The big picture outlook for January across much of the lower North American continent continues to trend further away from any serious chill and much of the central part of the United States will repeated visits from our friend El Torchy. New England appears well positioned to avoid large chunks of the this warm onslaught though I certainly would prefer a somewhat different jet configuration and a bit more arctic air at our disposal over the next two weeks and beyond. We have some good news on the snow side however and both pieces of news have to do with weather that will occur over the next week.
Our New Years Day system won't bring back the glory days of late November but it appears to be a solid base building event. Please excuse the prior post as I appeared to have my days and holidays mismatched and therefore gave an inaccurate version of the event timeline. New Years eve will indeed see generally cloudy skies with temperatures climbing from a morning low in the teens to afternoon readings up above freezing. Precipitation arrives just in time for 2019 and should arrive in the form of mostly snow with a bit of sleet mixed in. We are certainly capable of seeing some decent snowfall rates for a couple of hours before precipitation changes to mostly sleet before daybreak on New Years Day and eventually freezing rain and a bit of plain rain during the morning. Fear not however, though we aren't getting much in the way of powder, more of the 2-5 sleet/snow mash, we won't melt much of it on New Years Day. By the end of the day, much colder air will be arriving along with some snow flurries and what we hope will be a solid base to build upon down the road. If you are a particularly hungry powder hound and feel like venturing up toward the Canadian Border, Jay Peak will receive mostly snow and only a little sleet out of the New Years Day event (and no freezing rain) and certainly a healthier accumulation of around 6 inches. Go further north to Montreal and it's all powder and a very cold storm.
By the morning of January 2nd, temperatures will be back in single digit territory as will some sunshine and afternoon readings will only be in the teens. This airmass appeared quite formidable about a week ago but will have modified substantially by the it reaches New England and will continue to modify on Thursday Jan 3rd and Friday Jan 4th. Meanwhile the southern branch of the jet stream will continue to operate. It never wants to feel neglected during an El Nino winter so I must apologize failing to acknowledge its prominence. Our potential late-week system did in fact get a mention but certainly not a respectable one because there are strong indications that this will become a phased system by Thursday evening and a big precipitation producer by Thursday Night into Friday across New England. As I mentioned the cold is decaying by late in the week and rapidly so but the track of this storm, if it can choose an optimal course could deliver for Friday January 4th and into the weekend. I won't promise all powder and I can't even promise all snow yet but the storm certainly has my attention given our snow-starved status. This is the type of event that could deliver a foot or more of the good stuff so stay tuned and think positive thoughts.
We then have to contend with the ever-enhancing reality that January just isn't going to deliver much in the way of persistent cold weather this year. The PNA structure which looked so promising 4-5 days ago has disintegrated and most importantly, we simply can't shut down that pesky and strengthy Pacific jet stream. The various longer range ensembles remain at odds with what happens in the Pacific over the next 2-3 weeks but it doesn't appear likely that two key things will happen in that time frame. 1) The MJO will fully cycle into more favorable North American cold weather phases and weaken at least somewhat from its current strength 2) The development of a large scale high latitude blocking mechanism to counter the strengthy Pacific Jet and bring arctic cold southward.
We will likely have to make the best out of a marginal pattern and there is certainly hope we can do that this week. We are likely to get at least one mild day this upcoming weekend (Jan 5th-6th) before we get modestly chilly for a time next week. Yes, we are certainly capable of getting some additional snow in the January 7th-10th time frame but I can't promise any big stretches of sub-freezing temperatures though I think much of the warmth in this pattern will hit the central U.S. much harder than New England, milder air is certainly capable of reaching Vermont for shorter stretches of time
Sunday, December 30, 2018
Friday, December 28, 2018
Forecast for early January trends somewhat away from both cold and snow
Though not a catastrophic update, this is certainly not going to be one of my favorite blog posts this season. The outlook has shifted somewhat away from the more wintry and in our case optimistic vision of what we were hoping January would become. Though it doesn't appear as if El Torchy will dominate the weather across New England, arctic cold also appears as if it will have a much more minimal impact on North America than we had hoped. This isn't the end of the world in a month like January, but its a disturbing trend that I would like to see put to bed and quickly.
We have now endured two thaws in the past 10 days or so and incoming cold and accompanying snow flurries do not promise to provide much relief. There are some encouraging signs regarding the upcoming storm system which will be fueled by sub-tropical moisture in the western Gulf of Mexico on Sunday. The system, like the two priors, appears headed in a less than desirable direction but if you were to compare the track of these storms to one of my golf shots, at least this shot, though not a good one, might actually somehow end up somewhat playable. And this is essentially how I see this storm. Chilly air on Sunday December 30th will give way to a milder New Years Eve with temperatures up around 30 and a milder still New Years Day with afternoon readings near or above freezing. Precipitation will arrive on the evening of the 1st and is likely to fall as some snow or a snow sleet mixture for a time with a few inches of dense accumulation. A period of freezing rain is also possible by early Wednesday and so is another round of above freezing temperatures also early Wednesday. Unlike the two priors however, I doubt this storm provides a major opportunity for a thaw and may not at all. Much colder air will return by Wednesday evening and temperatures will be close to zero by Thursday morning.
Beyond Thursday January 3rd, the outlook doesn't appear terrible but I am especially disappointed at the disintegration of what once looked to be a prominent PNA structure. It still appears to be there but its rather pathetic looking. Furthermore, the lack of blocking at high latitudes is a glaring issue for North America and there is simply little mechanism available to eliminate a massive glob of anomalous warmth that will torch much of the eastern Rockies and central plains periodically through the first half of January. Though New England appears out of harms way, one would certainly feel more comfortable with more available arctic air. The cold air on January 3rd will quickly moderate by the weekend of January 5th and 6th and could give way to another round of above freezing temperatures, especially in valley locations. There is some southern branch energy around January 4th and 5th that appears largely cut off from a temporarily retreating and more dynamic polar branch of the jet. This part of the jet stream may return to provide New England with a return to colder weather around January 7th through the 10th but I had certainly hoped that the snow outlook up until the 7th and beyond the 7th would look better than it does. For now we have the snow/ice event on New Years and some weaker disturbances beyond that but nothing that looks especially significant.
We have now endured two thaws in the past 10 days or so and incoming cold and accompanying snow flurries do not promise to provide much relief. There are some encouraging signs regarding the upcoming storm system which will be fueled by sub-tropical moisture in the western Gulf of Mexico on Sunday. The system, like the two priors, appears headed in a less than desirable direction but if you were to compare the track of these storms to one of my golf shots, at least this shot, though not a good one, might actually somehow end up somewhat playable. And this is essentially how I see this storm. Chilly air on Sunday December 30th will give way to a milder New Years Eve with temperatures up around 30 and a milder still New Years Day with afternoon readings near or above freezing. Precipitation will arrive on the evening of the 1st and is likely to fall as some snow or a snow sleet mixture for a time with a few inches of dense accumulation. A period of freezing rain is also possible by early Wednesday and so is another round of above freezing temperatures also early Wednesday. Unlike the two priors however, I doubt this storm provides a major opportunity for a thaw and may not at all. Much colder air will return by Wednesday evening and temperatures will be close to zero by Thursday morning.
Beyond Thursday January 3rd, the outlook doesn't appear terrible but I am especially disappointed at the disintegration of what once looked to be a prominent PNA structure. It still appears to be there but its rather pathetic looking. Furthermore, the lack of blocking at high latitudes is a glaring issue for North America and there is simply little mechanism available to eliminate a massive glob of anomalous warmth that will torch much of the eastern Rockies and central plains periodically through the first half of January. Though New England appears out of harms way, one would certainly feel more comfortable with more available arctic air. The cold air on January 3rd will quickly moderate by the weekend of January 5th and 6th and could give way to another round of above freezing temperatures, especially in valley locations. There is some southern branch energy around January 4th and 5th that appears largely cut off from a temporarily retreating and more dynamic polar branch of the jet. This part of the jet stream may return to provide New England with a return to colder weather around January 7th through the 10th but I had certainly hoped that the snow outlook up until the 7th and beyond the 7th would look better than it does. For now we have the snow/ice event on New Years and some weaker disturbances beyond that but nothing that looks especially significant.
Wednesday, December 26, 2018
Pattern continues to look colder and increasingly favorable in longer range but next 5 days could certainly be better
It's a holiday week and we are trying to make the best out of 1-2 inches of snow and anxiously awaiting the return of more powdery conditions. Though this is one of those updates where I am afraid I might have to push the good news back just a bit, and from time to time I do have to do that, the outlook in the long range continues to look colder and snowier. In the short run however we still have one problematic weather system to get through Friday and right around the start of the new year which could deliver a bit of a mixed bag to the region. Hang tight though folks, winter will return.
Pretty close to a bluebird day on Thursday the 27th with temperatures remaining well below freezing but with winds about as calm as you can get on a winter day. The clouds and precipitation will arrive quickly on Friday however and its likely to arrive in the form of sleet and freezing rain just before daybreak. We aren't going to get any love from this storm track which appears poised to track north of the St Lawrence River Friday night. Additionally, there doesn't appear to be significant amounts of available moisture on Saturday when the colder air arrives. That said, the lingering cold on Friday will not get flushed out as easily as it did a week ago and most of the precipitation will fall with temperatures below or right near the freezing mark. We are likely to see temperatures surge into the 40's for a small window of time Friday night but conditions will turn sharply colder Saturday and we should see snow flurries accompany this colder change throughout the day. Sunday looks dry and chilly with temperatures ranging from near 5 in the morning to near 20 in the afternoon. The existing snow cover will have that "frozen hellscape" glisten yet again, a term that I fell in love with last year .
Something is brewing New Years Eve and Day but it involves another push of milder air. Models haven't entirely sorted this one out, but I think the Euro has the best handle on it as of Wednesday afternoon. Hopefully, the storm has a healthy overrunning induced front-side area of snow for us which is not exactly indicated right now but certainly possible in such a set up. Looking likely is some sleet and another period of ice. What doesn't appear likely is an extended thaw but temperatures could creep above freezing for a time on the afternoon of New Years Day. This is certainly a warmer change verses the last update when I had indicated that New Years Eve might mark the start of an extended stretch of below freezing temps.
I won't make such promises for this update but the ensembles continue to show a nice evolution to the upcoming pattern. The weakening jet in the Pacific is critical yes but what appears even more significant is the developing and rather beautiful looking positive PNA structure in the Yukon. This will bring some serious cold by January 6th and 7th and if we can keep the southern branch from going entirely dormant, we could see some serious East Coast action. Even before the arrival of the more intense arctic chill, there are hints of more storminess around January 3rd and 4th.
Pretty close to a bluebird day on Thursday the 27th with temperatures remaining well below freezing but with winds about as calm as you can get on a winter day. The clouds and precipitation will arrive quickly on Friday however and its likely to arrive in the form of sleet and freezing rain just before daybreak. We aren't going to get any love from this storm track which appears poised to track north of the St Lawrence River Friday night. Additionally, there doesn't appear to be significant amounts of available moisture on Saturday when the colder air arrives. That said, the lingering cold on Friday will not get flushed out as easily as it did a week ago and most of the precipitation will fall with temperatures below or right near the freezing mark. We are likely to see temperatures surge into the 40's for a small window of time Friday night but conditions will turn sharply colder Saturday and we should see snow flurries accompany this colder change throughout the day. Sunday looks dry and chilly with temperatures ranging from near 5 in the morning to near 20 in the afternoon. The existing snow cover will have that "frozen hellscape" glisten yet again, a term that I fell in love with last year .
Something is brewing New Years Eve and Day but it involves another push of milder air. Models haven't entirely sorted this one out, but I think the Euro has the best handle on it as of Wednesday afternoon. Hopefully, the storm has a healthy overrunning induced front-side area of snow for us which is not exactly indicated right now but certainly possible in such a set up. Looking likely is some sleet and another period of ice. What doesn't appear likely is an extended thaw but temperatures could creep above freezing for a time on the afternoon of New Years Day. This is certainly a warmer change verses the last update when I had indicated that New Years Eve might mark the start of an extended stretch of below freezing temps.
I won't make such promises for this update but the ensembles continue to show a nice evolution to the upcoming pattern. The weakening jet in the Pacific is critical yes but what appears even more significant is the developing and rather beautiful looking positive PNA structure in the Yukon. This will bring some serious cold by January 6th and 7th and if we can keep the southern branch from going entirely dormant, we could see some serious East Coast action. Even before the arrival of the more intense arctic chill, there are hints of more storminess around January 3rd and 4th.
Sunday, December 23, 2018
Not much new snow to promise in the short term but pattern looks better as we move toward 2019
After getting roughed up pretty good on Friday, we are obviously anxious for immediate relief and I can't promise much in the short term; in fact, we have another less than desirable set up late in the holiday week which we can detail a bit more today. That said, the jet in the Pacific will gradually weaken over the next two weeks, the PNA is expected to build and the outlook for the early part of 2019 looks colder and potentially snowy as well.
We do have a weaker weather system that has consolidated a small amount of moisture but has done mostly south of Vermont on Christmas Eve. As a result, the mountain won't see a lot of snow on Monday, just some flurries or a brief period of lighter snow which will amount to a coating or up to an inch. Those flurries will continue into the evening before conditions dry out and skies clear and allow for some limited sun on Christmas Day with temperatures starting out around 10 and rising into the 20's. An even weaker impulse will pass Wednesday but moisture is so limited that I would not hold out hope for much. It will remain below freezing Wednesday and that will continue through Thursday, a day which should feature more sun and some terrific visibility and relatively calm winds.
The Friday-Saturday situation has been and continues to be watched quite closely. If we are to salvage anything truly special out of this holiday stretch, it has to happen with this storm on the 28th or 29th. Unfortunately, we are still dealing with the by-products of an adverse pattern and a storm that will mature in the central Rockies and become a excellent snow producer for much much of the ski areas both in Colorado and New Mexico. With the storm reaching maturation in the central plains, some serious hurdles exist and another big warm push of air will make its way up the eastern seaboard. The situation however is not as trying as this past Friday. If one takes the consensus of available data, the track of the storm would be just north of the Canadian border and I've seen some simulations where the mild air fails in its efforts to reach the central and northern Green Mountains. There have been other simulations that have temperatures soaring well into the 40's again. In either case, I would expect a period of mixed precipitation early Friday with temperatures approaching the freezing mark and a possible period of rain later in the day if temperatures do indeed make that jump. This isn't etched in stone however, while last Friday's event more or less was by this point in time. Certainly worth checking back in a few days for an update.
In addition this weather situation evolves into Saturday as the front associated with this storm sags south, cold air reasserts itself across the state and rain potentially changes to a period of snow if a wave of low pressure along this boundary allows for such an extended period of precipitation. It is also possible that with the southward advance of what appears to be very chilly air Saturday, conditions simply dry out and precipitation is simply pushed too far south. Either way, I expect the drop in temperatures Saturday to mark the start of another extended period of sub-freezing temperatures and an opportunity to rebuild our damaged snowpack.
There has been lots of talk within the weather community and even in the media of looming and potentially historic arctic chill for January. The catalyst for such discussion is something called "Sudden Stratospheric Warming" or "SSW", a phenomenon which sometimes foreshadows extended periods of high latitude blocking in the jet stream and cold weather in lower North America. Dr Amy Butler out in Boulder who works at CIRES is a terrific follow on twitter @DrAHButler also has a blogspot page dedicated to SSW - Amy Butler's SSW Page, a phenomenon that has only gained attention within the last decade. Now, though a seemingly significant SSW is expected, it does not always lead to historic outbreaks of cold or even any outbreak of cold. Weather is very chaotic and historic weather requires a combination of factors to align in a specific way. From my vantage point, there is no evidence of historic cold but certainly a better looking pattern to start off 2019. This includes a softer Pacific jet and a positive PNA pattern capable of delivering a continuation of sub-freezing temperatures and most importantly an optimal storm track. I would thus expect 1-2 opportunities for snow New Years week, but can't promise anything big quite yet.
We do have a weaker weather system that has consolidated a small amount of moisture but has done mostly south of Vermont on Christmas Eve. As a result, the mountain won't see a lot of snow on Monday, just some flurries or a brief period of lighter snow which will amount to a coating or up to an inch. Those flurries will continue into the evening before conditions dry out and skies clear and allow for some limited sun on Christmas Day with temperatures starting out around 10 and rising into the 20's. An even weaker impulse will pass Wednesday but moisture is so limited that I would not hold out hope for much. It will remain below freezing Wednesday and that will continue through Thursday, a day which should feature more sun and some terrific visibility and relatively calm winds.
The Friday-Saturday situation has been and continues to be watched quite closely. If we are to salvage anything truly special out of this holiday stretch, it has to happen with this storm on the 28th or 29th. Unfortunately, we are still dealing with the by-products of an adverse pattern and a storm that will mature in the central Rockies and become a excellent snow producer for much much of the ski areas both in Colorado and New Mexico. With the storm reaching maturation in the central plains, some serious hurdles exist and another big warm push of air will make its way up the eastern seaboard. The situation however is not as trying as this past Friday. If one takes the consensus of available data, the track of the storm would be just north of the Canadian border and I've seen some simulations where the mild air fails in its efforts to reach the central and northern Green Mountains. There have been other simulations that have temperatures soaring well into the 40's again. In either case, I would expect a period of mixed precipitation early Friday with temperatures approaching the freezing mark and a possible period of rain later in the day if temperatures do indeed make that jump. This isn't etched in stone however, while last Friday's event more or less was by this point in time. Certainly worth checking back in a few days for an update.
In addition this weather situation evolves into Saturday as the front associated with this storm sags south, cold air reasserts itself across the state and rain potentially changes to a period of snow if a wave of low pressure along this boundary allows for such an extended period of precipitation. It is also possible that with the southward advance of what appears to be very chilly air Saturday, conditions simply dry out and precipitation is simply pushed too far south. Either way, I expect the drop in temperatures Saturday to mark the start of another extended period of sub-freezing temperatures and an opportunity to rebuild our damaged snowpack.
There has been lots of talk within the weather community and even in the media of looming and potentially historic arctic chill for January. The catalyst for such discussion is something called "Sudden Stratospheric Warming" or "SSW", a phenomenon which sometimes foreshadows extended periods of high latitude blocking in the jet stream and cold weather in lower North America. Dr Amy Butler out in Boulder who works at CIRES is a terrific follow on twitter @DrAHButler also has a blogspot page dedicated to SSW - Amy Butler's SSW Page, a phenomenon that has only gained attention within the last decade. Now, though a seemingly significant SSW is expected, it does not always lead to historic outbreaks of cold or even any outbreak of cold. Weather is very chaotic and historic weather requires a combination of factors to align in a specific way. From my vantage point, there is no evidence of historic cold but certainly a better looking pattern to start off 2019. This includes a softer Pacific jet and a positive PNA pattern capable of delivering a continuation of sub-freezing temperatures and most importantly an optimal storm track. I would thus expect 1-2 opportunities for snow New Years week, but can't promise anything big quite yet.
Thursday, December 20, 2018
Thaw looks increasingly damaging Friday, longer range looks a bit more promising
No, the situation this Friday is hardly ideal and the news hasn't gotten any better over the last few days. Based on the latest data, the track of this rainy weather system appears both farther north and less occluded which means southerly winds driving very warm air into the entire state. Rain begins Thursday night with temperatures in the 30's and will become periodically heavy by daybreak as temperatures warm slightly. The big rise in temperatures occurs during the day and will correspond to an increase in snow-eating southerly winds. As temperatures peak in the low 50's in many spots, thunderstorms are possible before most of the heavy stuff pushes off to the east during the evening. Really no way to sugarcoat this set of circumstances anymore, it will be a damaging thaw for ski areas across the entire state. Fortunately, there is some good news in the longer range outlook. Gradually we will gain access to more cold air and although the possibility remains for another mitigated thaw around the 29th, the chances for snowfall will grow in frequency as we advance toward 2019.
Colder air arrives Saturday but it will take some time, probably most of the day below 2500 feet, for temperatures to fall back below the freezing mark. The higher elevations across the northern half of the will see a bit of snow and the summits can expect a small accumulation, but with the exception of Jay Peak, I wouldn't expect much more than a rather paltry consolation prize after Friday's washout. We should see a limited return of sunshine on Sunday with calmer winds and sub-freezing temperatures ranging from the high teens in the morning to near 30 in the afternoon.
The first system worth watching arrives early on Christmas Eve. This is a clipper system of total insignificance that will attain some limited southern stream moisture and thus bears watching because these situations are often fluid and are often decided late in the forecast game. Snow would begin prior to daybreak and persist through at least part of the day. Accumulations appear to be pretty light but again, things can change. Christmas Day continues to appear dry but there is a weaker impulse on the weather map that could keep the snow flurry activity going and also help entrench some needed cold into the state. This airmass should keep the mountain sub-freezing through Thursday and a piece of a intensifying system in the Rocky Mountain region could still spread some snow into the state some time in this time frame though this appears less likely today verses a few days ago.
The aforementioned Rocky Mountain storm is indicated to take another less than optimal track late next week but thanks to the presence of more arctic cold, we remain in the mix for wintry precipitation. Another period of above freezing temperatures is also a possibility but this surge of warmth appears less both less intense and shorter in duration if it were to occur at all.
Though the longer range outlook, the part that includes the New Years holiday and beyond, continues to appear relatively neutral, there are indications of more snow possibilities. The better part of this story is the descending NAO index and the possibility that this evolves into a high latitude blocking event that helps anchor the pattern around and beyond New Years holiday. This wouldn't be the type of pattern to deliver bone chilling cold, such as what we got early in 2018, and I am not sure we really want that. Instead, it could be the pattern that sets the stage for a few winter storms which will be much needed after this latest sub-tropical breach.
Colder air arrives Saturday but it will take some time, probably most of the day below 2500 feet, for temperatures to fall back below the freezing mark. The higher elevations across the northern half of the will see a bit of snow and the summits can expect a small accumulation, but with the exception of Jay Peak, I wouldn't expect much more than a rather paltry consolation prize after Friday's washout. We should see a limited return of sunshine on Sunday with calmer winds and sub-freezing temperatures ranging from the high teens in the morning to near 30 in the afternoon.
The first system worth watching arrives early on Christmas Eve. This is a clipper system of total insignificance that will attain some limited southern stream moisture and thus bears watching because these situations are often fluid and are often decided late in the forecast game. Snow would begin prior to daybreak and persist through at least part of the day. Accumulations appear to be pretty light but again, things can change. Christmas Day continues to appear dry but there is a weaker impulse on the weather map that could keep the snow flurry activity going and also help entrench some needed cold into the state. This airmass should keep the mountain sub-freezing through Thursday and a piece of a intensifying system in the Rocky Mountain region could still spread some snow into the state some time in this time frame though this appears less likely today verses a few days ago.
The aforementioned Rocky Mountain storm is indicated to take another less than optimal track late next week but thanks to the presence of more arctic cold, we remain in the mix for wintry precipitation. Another period of above freezing temperatures is also a possibility but this surge of warmth appears less both less intense and shorter in duration if it were to occur at all.
Though the longer range outlook, the part that includes the New Years holiday and beyond, continues to appear relatively neutral, there are indications of more snow possibilities. The better part of this story is the descending NAO index and the possibility that this evolves into a high latitude blocking event that helps anchor the pattern around and beyond New Years holiday. This wouldn't be the type of pattern to deliver bone chilling cold, such as what we got early in 2018, and I am not sure we really want that. Instead, it could be the pattern that sets the stage for a few winter storms which will be much needed after this latest sub-tropical breach.
Tuesday, December 18, 2018
Rainy thaw still in line for Friday while holiday week appears to be a "hit and miss" situation
Winter has retreated over a large expanse of the eastern United States yet has maintained a somewhat tenuous grip on interior New England and much of Vermont over the past week. As of the 18th, much of interior New England has been the coldest, relative to normal, of any place in the country during the month of December. There are very special years when MRG can avoid serious thaws for 6-8 week stretches but even in those years, it typically doesn't happen in December and it certainly won't happen in 2018 in spite of the 80 inches so far this season. The mountain will bask in sunshine and great visibility Wednesday which will allow temperatures to rebound from a morning low of near 5 to an afternoon high not far from the freezing mark. Limited sunshine will continue into Thursday along with milder, above freezing afternoon temperatures.
Can we contain this late-week abomination ? Can we prevent a disastrous melt-off and the utter exasperation we all felt after losing all of our snow on January 12th last season. That was a crippling event that we would certainly rather avoid going into Christmas. I can honestly say that it looks rather bad, but perhaps only half as bad as January 12th, if we are to use that as a reference point. Clouds will blanket the region Thursday night and rain will begin at around daybreak Friday with temperatures in the lower to middle 30's. Yes, there could be some freezing rain in a few spots early but temperatures will warm into the 40's from Mt Snow northward to Jay Peak (it won't matter with this storm). Keeping temperatures in the low 40's would be critical however to containing the melt-off and we can do this if the storm occludes and effectively pinches off the northern edge of the warm sector. This will also help mitigate the wind which when combined with above-freezing dewpoints can eat up snow cover faster than Mookie Betts can run the bases. I don't think we can avoid a period of pretty heavy rain, which is predicted to fall during the midday hours Friday. By Saturday, the rain will be lighter and some colder air aloft will help change this rain to a bit of snow at the highest elevations, but I woudn't expect to see any snow until very late in the afternoon.
Colder air will, very gradually work its way back into Vermont and snow showers, which will begin late Saturday up high, will overspread the entire valley and is likely to drop a few inches of snow on the mountains by Sunday. There is some dissension among the various computer simulations as to the available moisture Sunday so we will need another day or two to clarify that and the potential for accumulating snow beyond Saturday night. Snow showers or flurries could continue into Christmas Eve but it appears as if drier weather will prevail as the day continues to progress. Christmas Day appears appears dry and seasonable with at least some limited sunshine.
Milder air will try make another push at the region late in the holiday week (between the 27th and 29th), but before that happens there is the potential to sneak in a snow event. There are indications that a wave of low pressure could advance out ahead of a bigger storm in the eastern Rocky Mountain region. This would open the door for some accumulating snow either on the 26th or 27th. What we would hope to avoid is a massive, consolidated storm advancing out of the Rocky Mountains late next week. Such a storm might end up delivering another significant thaw to the region but that is not what is currently indicated and although it's early in the speculation phase of the forecast game, it does appear as if there is more cold air to work with next week in spite of the less than ideal weather pattern. So it's worth remaining optimistic for now and expecting a mitigated round of milder temperatures in that period between the 27th and 29th which may include some snow and some mixed precipitation as well.
Looking beyond, there are continued signs that the intensity of the jet in the Pacific will weaken ever so gradually. That said, the pattern is not indicated to reverse into arctic mode but rather neutralize into no particular mode at all. There aren't indications of high latitude blocking or any mechanism that might deliver a widespread outbreak of arctic air to the region yet I've seen some press in recent days predicting such for January. In truth, January is not a great time for us to get the onslaught of polar air since it typically suppresses the action well to our south and thus a neutral pattern might end up being the the most productive, especially if we can effectively combine a few moist southern streamers with some limited arctic cold.
Can we contain this late-week abomination ? Can we prevent a disastrous melt-off and the utter exasperation we all felt after losing all of our snow on January 12th last season. That was a crippling event that we would certainly rather avoid going into Christmas. I can honestly say that it looks rather bad, but perhaps only half as bad as January 12th, if we are to use that as a reference point. Clouds will blanket the region Thursday night and rain will begin at around daybreak Friday with temperatures in the lower to middle 30's. Yes, there could be some freezing rain in a few spots early but temperatures will warm into the 40's from Mt Snow northward to Jay Peak (it won't matter with this storm). Keeping temperatures in the low 40's would be critical however to containing the melt-off and we can do this if the storm occludes and effectively pinches off the northern edge of the warm sector. This will also help mitigate the wind which when combined with above-freezing dewpoints can eat up snow cover faster than Mookie Betts can run the bases. I don't think we can avoid a period of pretty heavy rain, which is predicted to fall during the midday hours Friday. By Saturday, the rain will be lighter and some colder air aloft will help change this rain to a bit of snow at the highest elevations, but I woudn't expect to see any snow until very late in the afternoon.
Colder air will, very gradually work its way back into Vermont and snow showers, which will begin late Saturday up high, will overspread the entire valley and is likely to drop a few inches of snow on the mountains by Sunday. There is some dissension among the various computer simulations as to the available moisture Sunday so we will need another day or two to clarify that and the potential for accumulating snow beyond Saturday night. Snow showers or flurries could continue into Christmas Eve but it appears as if drier weather will prevail as the day continues to progress. Christmas Day appears appears dry and seasonable with at least some limited sunshine.
Milder air will try make another push at the region late in the holiday week (between the 27th and 29th), but before that happens there is the potential to sneak in a snow event. There are indications that a wave of low pressure could advance out ahead of a bigger storm in the eastern Rocky Mountain region. This would open the door for some accumulating snow either on the 26th or 27th. What we would hope to avoid is a massive, consolidated storm advancing out of the Rocky Mountains late next week. Such a storm might end up delivering another significant thaw to the region but that is not what is currently indicated and although it's early in the speculation phase of the forecast game, it does appear as if there is more cold air to work with next week in spite of the less than ideal weather pattern. So it's worth remaining optimistic for now and expecting a mitigated round of milder temperatures in that period between the 27th and 29th which may include some snow and some mixed precipitation as well.
Looking beyond, there are continued signs that the intensity of the jet in the Pacific will weaken ever so gradually. That said, the pattern is not indicated to reverse into arctic mode but rather neutralize into no particular mode at all. There aren't indications of high latitude blocking or any mechanism that might deliver a widespread outbreak of arctic air to the region yet I've seen some press in recent days predicting such for January. In truth, January is not a great time for us to get the onslaught of polar air since it typically suppresses the action well to our south and thus a neutral pattern might end up being the the most productive, especially if we can effectively combine a few moist southern streamers with some limited arctic cold.
Saturday, December 15, 2018
Nice dose of snow coming late Monday but outlook takes a bad turn on storm late next week
Though we still have a dose of terrain enhanced snow to look forward to early in the upcoming week, the outlook has taken a bad turn today regarding what appears to be a sizable late week weather system. The Euro model showed signs of this subtropical phasing early Friday and other computer guidance has jumped on board. Often times "phasing" is a good thing but not this far south and this far west. More on that below.
In the meantime I would try and enjoy this upcoming dose of terrain enhanced snow. Precipitation Monday morning could remain a mix of rain and snow but the polar jet involvement will provide both the instability and cold air and shift everything to snow by afternoon which should occasionally be rather heavy. The snow would be rather fluffy thanks to the convective nature of the precipitation but the wind will be blowing rather fiercely which will compact some of what falls. Tuesday appears to be the best day to get out and enjoy it with snow showers continuing through at least part of the day and temperatures holding in the teens after falling into the 20's by Monday evening. Between late Monday and midday Tuesday, I am guessing the snow will total 4-8 inches but we could find ourselves in the lucky spot and score something even nicer. We deserve it because what's coming after isn't pretty.
Some clearing skies Tuesday night will bring temperatures back to the single numbers and Wednesday will feature a good bit of sunshine and afternoon temperatures of up around 30. Thursday will also be precipitation-free but will feature a bit more cloudiness and temperatures about 8 degrees warmer. We then get to our late week storm which appears to be an example of Nino delivering a large and very unwanted Christmas gift. Models hadn't really indicated too much activity in the southern branch of the jet but during El Nino winters, this activity is almost always underestimated and suddenly it's there and very ominous looking. The storm will begin to take shape along the gulf coast in the form of thunderstorms but the forming low pressure will phase with southeastward advancing clipper system and explode. Sometimes this is fantastic but we don't have the cold air and the phasing will simply occur way too early which allows the storm to suck very warm Atlantic Ocean air well inland, which it will do by late Friday all over New England from Cape Cod to Mt Washington. Rain will arrive early Friday and temperatures will continue to warm quite possibly making a run at 50 sometime Friday evening. We have to hope that the storm will simply occlude which will pinch off the northwestward advance of mild air and allow for a more modest thaw as opposed to a devastating one. If that happens, perhaps some of the most intense rain and mild air can confine itself to the coast and we can think of ourselves as lucky limit the rainfall to under a half an inch.
The high country will see a return to near freezing temperatures Saturday but the melt will continue across the low lying valleys. Snow showers will also return to areas above 2000 feet and we might see some accumulation as the storm proceeds into the Canadian Maritimes
The remaining issue for us is the continued presence of this positive EPO structure which is now indicated to persist through the Christmas holiday and probably through New Years as well. This does not appear to be a full fledged Evil Empire wrought with multiple rounds of Sir El Torchy, but we will need more help from our teleconnection friends to turn this weather pattern in the right direction and we could more high latitude blocking in the jet stream to send arctic air back in our direction. All of this said, since the EPO isn't overwhelmingly intense, both cold air and some snowfall will remain a possibility during the Xmas week though so does the possibility for another thaw. Lets give us some credit for surviving a pretty healthy chunk of this adverse MJO phase but we can't survive forever. When the MJO finally cycles through these phases, which it is doing slowly, we will slow the jet in the Pacific and get a pattern more conducive for cold and snowy conditions. I was hoping this might happen right around Christmas but unfortunately, we have to shift those expectations somewhat in light of what is being currently indicated.
In the meantime I would try and enjoy this upcoming dose of terrain enhanced snow. Precipitation Monday morning could remain a mix of rain and snow but the polar jet involvement will provide both the instability and cold air and shift everything to snow by afternoon which should occasionally be rather heavy. The snow would be rather fluffy thanks to the convective nature of the precipitation but the wind will be blowing rather fiercely which will compact some of what falls. Tuesday appears to be the best day to get out and enjoy it with snow showers continuing through at least part of the day and temperatures holding in the teens after falling into the 20's by Monday evening. Between late Monday and midday Tuesday, I am guessing the snow will total 4-8 inches but we could find ourselves in the lucky spot and score something even nicer. We deserve it because what's coming after isn't pretty.
Some clearing skies Tuesday night will bring temperatures back to the single numbers and Wednesday will feature a good bit of sunshine and afternoon temperatures of up around 30. Thursday will also be precipitation-free but will feature a bit more cloudiness and temperatures about 8 degrees warmer. We then get to our late week storm which appears to be an example of Nino delivering a large and very unwanted Christmas gift. Models hadn't really indicated too much activity in the southern branch of the jet but during El Nino winters, this activity is almost always underestimated and suddenly it's there and very ominous looking. The storm will begin to take shape along the gulf coast in the form of thunderstorms but the forming low pressure will phase with southeastward advancing clipper system and explode. Sometimes this is fantastic but we don't have the cold air and the phasing will simply occur way too early which allows the storm to suck very warm Atlantic Ocean air well inland, which it will do by late Friday all over New England from Cape Cod to Mt Washington. Rain will arrive early Friday and temperatures will continue to warm quite possibly making a run at 50 sometime Friday evening. We have to hope that the storm will simply occlude which will pinch off the northwestward advance of mild air and allow for a more modest thaw as opposed to a devastating one. If that happens, perhaps some of the most intense rain and mild air can confine itself to the coast and we can think of ourselves as lucky limit the rainfall to under a half an inch.
The high country will see a return to near freezing temperatures Saturday but the melt will continue across the low lying valleys. Snow showers will also return to areas above 2000 feet and we might see some accumulation as the storm proceeds into the Canadian Maritimes
The remaining issue for us is the continued presence of this positive EPO structure which is now indicated to persist through the Christmas holiday and probably through New Years as well. This does not appear to be a full fledged Evil Empire wrought with multiple rounds of Sir El Torchy, but we will need more help from our teleconnection friends to turn this weather pattern in the right direction and we could more high latitude blocking in the jet stream to send arctic air back in our direction. All of this said, since the EPO isn't overwhelmingly intense, both cold air and some snowfall will remain a possibility during the Xmas week though so does the possibility for another thaw. Lets give us some credit for surviving a pretty healthy chunk of this adverse MJO phase but we can't survive forever. When the MJO finally cycles through these phases, which it is doing slowly, we will slow the jet in the Pacific and get a pattern more conducive for cold and snowy conditions. I was hoping this might happen right around Christmas but unfortunately, we have to shift those expectations somewhat in light of what is being currently indicated.
Friday, December 14, 2018
Big improvements for the snow outlook next week with some substantial snow amounts possible for high country Mon/Tue
Thanks to the combination of northwest flow at jet stream level and the refrigerating effect of the existing deep December snowpack, cold air continues to dominate interior New England in unique fashion. Unique because the region is about the only place in the United States which is experiencing winter conditions as the cold has been largely scoured away from much of the rest of the nation. It's been a long time since I remember a weather pattern that has left us this distinguished. I certainly recall a few years in the early 90's where New England was the coldest relative to average for the winter season and one season in particular, 1991-92 which especially stands out because of how dramatic it was and because it was also a El Nino winter, much like this one and of a similar intensity.
I am delighted to report that the outlook going forward continues to improve. There are no particular indications of any big storms and the weather pattern continues to look non-arctic both for Vermont and for much of the lower half of North America. That said, the outlook on temperatures continues to move in the "not as mild" direction and what's better is the introduction of some accumulating snowfall to the outlook for at least early next week and quite possibly later in the week as well.
All of that talk about the tightened jet stream in the Pacific will finally bring some milder temperatures to Vermont, but we aren't expecting much if any rain. Temperatures will sneak above the freezing mark by evening on Friday and stay there for a good part of Saturday but will will remain below the 40-degree mark. In addition, much of the rain will stay to the south of Vermont and winds will remain calm. This basically means very little damage to the existing snow and clearing skies Saturday night will allow temperatures to chill back down to well-below freezing levels. Some early sun will send readings back toward the freezing mark Sunday before clouds encompass the region in advance of our next interesting little weather system.
It would be wrong to call it a Alberta Clipper since it won't enter the nation via that route. For now, lets just refer to it as the "Provincial Plunger" since the impulse originates from a vigorous Canadian storm system that will travel across central Canada over the weekend. This particular weather feature will grab the polar jet and yank it southward toward northern New England. Though the storm isn't flush with moisture, it has a little bit and will also bring the combination of instability and a very favorable wind direction for the north central Green's. Snowfall across the high country will begin early Monday and persist through much of the day into Monday night and even Tuesday. Accumulations will be elevations sensitive and the snow will be squally in nature but could be substantial. It would be very early to promise a foot-plus but that is within the range of possibilities. For now, I think 6 inches over that two day span (Monday-Tuesday) is a conservative guess and this is with modest temperatures mostly in the twenties. Though the rest of the week looks mild over the rest of the United States and not especially cold in New England, readings will generally remain below the freezing mark and the late week period brings the possibility for more snowfall or at worst some mixed precipitation (if everything goes wrong and that is not the trend). This second system is more of a traditional clipper-like storm which may or may not travel far enough south to deliver more snowfall but I have to admit, the outlook looks vastly improved.
Moving forward into the days immediately prior-to and during the X-Mas holiday, we are still contending with some adverse drivers in the weather pattern. The Arctic Oscillation is expected to be more negative now verses expectations from a few days ago and this will counter the negative influences from the MJO-EPO. But those influences will remain somewhat in play going into the holiday at a slightly weaker level. Can we again produce a little more late-2018 magic ? Quite possible again, but it would be disingenuous of me to suggest that we are obstacle-free in the Dec 21-26 range.
I am delighted to report that the outlook going forward continues to improve. There are no particular indications of any big storms and the weather pattern continues to look non-arctic both for Vermont and for much of the lower half of North America. That said, the outlook on temperatures continues to move in the "not as mild" direction and what's better is the introduction of some accumulating snowfall to the outlook for at least early next week and quite possibly later in the week as well.
All of that talk about the tightened jet stream in the Pacific will finally bring some milder temperatures to Vermont, but we aren't expecting much if any rain. Temperatures will sneak above the freezing mark by evening on Friday and stay there for a good part of Saturday but will will remain below the 40-degree mark. In addition, much of the rain will stay to the south of Vermont and winds will remain calm. This basically means very little damage to the existing snow and clearing skies Saturday night will allow temperatures to chill back down to well-below freezing levels. Some early sun will send readings back toward the freezing mark Sunday before clouds encompass the region in advance of our next interesting little weather system.
It would be wrong to call it a Alberta Clipper since it won't enter the nation via that route. For now, lets just refer to it as the "Provincial Plunger" since the impulse originates from a vigorous Canadian storm system that will travel across central Canada over the weekend. This particular weather feature will grab the polar jet and yank it southward toward northern New England. Though the storm isn't flush with moisture, it has a little bit and will also bring the combination of instability and a very favorable wind direction for the north central Green's. Snowfall across the high country will begin early Monday and persist through much of the day into Monday night and even Tuesday. Accumulations will be elevations sensitive and the snow will be squally in nature but could be substantial. It would be very early to promise a foot-plus but that is within the range of possibilities. For now, I think 6 inches over that two day span (Monday-Tuesday) is a conservative guess and this is with modest temperatures mostly in the twenties. Though the rest of the week looks mild over the rest of the United States and not especially cold in New England, readings will generally remain below the freezing mark and the late week period brings the possibility for more snowfall or at worst some mixed precipitation (if everything goes wrong and that is not the trend). This second system is more of a traditional clipper-like storm which may or may not travel far enough south to deliver more snowfall but I have to admit, the outlook looks vastly improved.
Moving forward into the days immediately prior-to and during the X-Mas holiday, we are still contending with some adverse drivers in the weather pattern. The Arctic Oscillation is expected to be more negative now verses expectations from a few days ago and this will counter the negative influences from the MJO-EPO. But those influences will remain somewhat in play going into the holiday at a slightly weaker level. Can we again produce a little more late-2018 magic ? Quite possible again, but it would be disingenuous of me to suggest that we are obstacle-free in the Dec 21-26 range.
Monday, December 10, 2018
Though the pattern appears far from ideal in the 10 days leading up to Xmas, we may find a way through most of it
It has a mid-winter feel to it across Vermont thanks to the recent outbreak of colder temperatures, a little bit of new snow and plenty of existing snow from previous storms. We all know how totally erratic early December can be and to be perfectly frank, it usually sucks. December is now 4-6 degrees below average thanks to the weekend cold spell and the skiing remains incredibly good given the early date so we have no right to complain. Additionally we have some good news. Though the pattern leaves a few things to be desired in the 10 days leading up to Christmas, we may be able to find a way through most of it. Furthermore, gazing way out beyond the Christmas holiday, there are signs of some improvement and the possibility of infusing more cold into the mix as we approach the New Years holiday.
On twitter, I had teased about the possibility of some mid-week snow. This situation is real thanks to the fact that New England will be about the only location encompassed by cold this week and is at the clashing point between this existing cold and the advancing mild air building across the middle part of North America. A clipper system would be the catalyst for snow but this system appears very devoid of moisture. Still, we get a pretty good wind direction Tuesday night and early Wednesday so we might be able to squeeze out a 1-3 inch refresher. Most of this week however will simply remain chilly thanks to that northwest flow in the jet stream. This will mean low temperatures in the single numbers and teens and high temperatures in the 20's. We can also expect some intervals of sunshine through Thursday and more clouds by Friday.
Speaking of Friday, it continues to look like the beginning of a more adverse stretch of weather conditions. That said, it continues to trend in the "not that bad" direction. This is an example of some of the positive aspects of an El Nino. In this case, the southern branch of the jet stream appears powerful enough to potentially push this storm through to the Atlantic Coast rather than allowing the system to make a northward turn toward the Great Lakes and central Quebec. It also helps to have all that early season November cold effectively chill the Great Lakes aggregate down and this lessens some of that thermal gravity which can also pull storms in that aforementioned unfavorable direction. In spite of all this, temperatures are still expected to moderate toward the freezing mark by late Friday or early Saturday and it remains possible to see a bit of freezing rain or rain but it's also quite possible that we get through the entire weekend without much of any precipitation. Given the circumstances one would have to consider this a massive victory.
The above average temperatures which will commence in this Friday/Saturday time frame will continue through Sunday and into the upcoming week in the days approaching the Christmas holiday. Though it doesn't appear to be a blowtorch, temperatures will get above freezing multiple times and it's likely that we see some additional rainfall. The strength of the Pacific Jet and some of the adverse MJO phases that are contributing to this strength will peak in the current week and slowly subside as we move into next week. In the days just prior to Xmas the pattern appears neutral and it even appears possible, as mentioned, that we can introduce some arctic air back into the mix.
On twitter, I had teased about the possibility of some mid-week snow. This situation is real thanks to the fact that New England will be about the only location encompassed by cold this week and is at the clashing point between this existing cold and the advancing mild air building across the middle part of North America. A clipper system would be the catalyst for snow but this system appears very devoid of moisture. Still, we get a pretty good wind direction Tuesday night and early Wednesday so we might be able to squeeze out a 1-3 inch refresher. Most of this week however will simply remain chilly thanks to that northwest flow in the jet stream. This will mean low temperatures in the single numbers and teens and high temperatures in the 20's. We can also expect some intervals of sunshine through Thursday and more clouds by Friday.
Speaking of Friday, it continues to look like the beginning of a more adverse stretch of weather conditions. That said, it continues to trend in the "not that bad" direction. This is an example of some of the positive aspects of an El Nino. In this case, the southern branch of the jet stream appears powerful enough to potentially push this storm through to the Atlantic Coast rather than allowing the system to make a northward turn toward the Great Lakes and central Quebec. It also helps to have all that early season November cold effectively chill the Great Lakes aggregate down and this lessens some of that thermal gravity which can also pull storms in that aforementioned unfavorable direction. In spite of all this, temperatures are still expected to moderate toward the freezing mark by late Friday or early Saturday and it remains possible to see a bit of freezing rain or rain but it's also quite possible that we get through the entire weekend without much of any precipitation. Given the circumstances one would have to consider this a massive victory.
The above average temperatures which will commence in this Friday/Saturday time frame will continue through Sunday and into the upcoming week in the days approaching the Christmas holiday. Though it doesn't appear to be a blowtorch, temperatures will get above freezing multiple times and it's likely that we see some additional rainfall. The strength of the Pacific Jet and some of the adverse MJO phases that are contributing to this strength will peak in the current week and slowly subside as we move into next week. In the days just prior to Xmas the pattern appears neutral and it even appears possible, as mentioned, that we can introduce some arctic air back into the mix.
Thursday, December 6, 2018
Short term forecast remains cold but with limited snow, while challenges remain in the longer range
We have a relatively tranquil blog update which includes an ever so slightly colder outlook in the short term, still some challenges looming beyond December 13th and only limited chances for new snow. Beyond the clipper system Thursday night, a weak impulse and some warm advection is expected to spread some clouds and some light snow into the region for a time late Saturday and Saturday night. The story for the next few days is simply the cold weather however which appears now to be the coldest of the season so far. The arctic air mass will keep temperatures in the teens for much of the day Friday, provide for some blue skies late in the day and set the stage for sub-zero readings Friday night and early Saturday. Saturday will also see some sunshine but only enough to boost temperatures up to around 20 before clouds move in. Sunday's readings will approach 30 as the arctic air erodes somewhat and we get some limited sunshine on the heels of what should be a light accumulation of snow Saturday night if at all.
Looking at the big picture, the story for the next week remains the tightening Pacific jet and the rapidly increasing EPO index. Though the models hedged and debated for a time on the intensity of the EPO change, it is expected to more or less max out around the 12th or 13th and then weaken somewhat beyond that. A shift of that magnitude is going to cause a substantial response from the standpoint of actual weather across North America and unsurprisingly, the biggest is the arctic air going into retreat-mode. Interestingly, in spite of milder temperatures across a large portion of the midwest and plains, northwest flow at jet stream level will keep it on the chilly side across New England for almost another week. The deep snowpack that remains doesn't hurt either. Barring a miracle, we won't taste any part of the big southern streamer Sunday into Monday and snowfall through the middle part of next week will be minimal, though we may be able to squeeze out an inch here and there.
Once we move toward the 14th and 15th the thaw questions loom. The good news here is that it remains just a question. Though we know how limited the availability of arctic cold will be by this point in time, the southern branch of the jet is still a force to be reckoned and will likely keep the storm track to the regions south, likely stunting the intensity of the mild air. Yes, it's within the possibility spectrum to miraculously turn this potential thaw into some sort of winter weather event but it's asking a lot with eastern Canada almost entirely devoid of serious cold.
The aforementioned conundrum is likely to continue beyond the 15th. The pattern doesn't appear overwhelmingly mild but glaringly non-arctic. Certainly a scenario very common during El Nino winters, and although this ENSO isn't nearly the magnitude of 2015-2016, it has strengthened in the last few weeks to about 1.2 C above normal. On the flip side, we just recorded a massive snow cover number in the Northern Hemisphere during the month of November. This colder feedback will help to counteract some of the warmer feedbacks caused by the state of the ENSO going forward or at least that is my hope.
Tuesday, December 4, 2018
Forecast trends drier with chilly temperatures prevailing though Dec 12 and a possible thaw Dec 14-15
Colder temperatures have arrived and a few inches of snow came with it. Tuesday was the beginning of an extended stretch of sub-freezing temperatures, but the forecast has trended drier over the past 48 hours. We also are expecting some of the cold to retreat somewhat during the middle of the month, but this "retreat" doesn't appear especially severe right for now and temperatures appear just slightly above average in the period starting December 13th to about the solstice which is about as far out as we can reasonably prognosticate.
Wednesday will finally feature more than a glimpse of sunshine which will help boost temperatures into the 20's along with relatively calm winds. Clouds are expected to return Thursday and some light snow is expected from a clipper system Thursday night. Honestly, I had higher hopes for this system as it appears totally deprived of moisture and appears way too far north for any late coastal strengthening. Still, it will bring with it another charge of arctic cold, rivaling the Thanksgiving cold outbreak with temperatures below zero Saturday morning and rising toward 20 Saturday afternoon. Saturday will feature more sunshine however which is a welcome sight during what is the darkest days of the season.
Forecasters are watching the big southern streamer which is expected to slam the Gulf Coast with rain and thunderstorms this weekend. By Sunday evening, the storm will continue to be a sizable weather producer centered near the Carolina coast. Given the right configuration in the jet stream, this storm could make a northward turn and cripple the entire northeast with snowfall but the circumstances just aren't right this time. The polar jet is retreating and a large ridge in the jet stream is expected to build over south-central Canada just as the storm reaches the coastline. This simply does not provide a clear northward or northeastward avenue for this storm to travel and its speed is expected to slow, perhaps even stall and thus keeping the impact area smaller. Some snow could certainly fall across inland portions of Virginia and West Virginia but at this point I would be surprised to see this storm become a serious New England impact, even in southern sections though one can never say never, not with northeast weather.
As mentioned in previous posts, the jet in the Pacific will be tightening and strengthening and will force the polar jet and arctic air to go into retreat mode. This appears to be a slow process right now however for a couple reasons. First, given the time of the year and the low sun angle, it will take some time for the cold air to erode and will need some advection to do it. Secondly, the Pacific will go into full "evil empire" mode. No, we could certainly do a lot better but we've also seen a lot worse. Temperatures are thus expected to remain below freezing through at least the 12th or 13th of December. Barring a miracle from the aforementioned coastal storm, snowfall will also be minimal but there is a small disturbance capable of delivering a light accumulation this weekend.
We are likely to see a round of above freezing temperatures and rainfall sometime around the 14th-15th of the month which coincides fairly well with the peaking EPO (Pacific Jet strength). There doesn't appear to be any mechanism to provide for the return of arctic air after the 15th but the pattern doesn't appear to be terrible. If I had to guess, temperatures would likely remain above average but we might be able to reintroduce the possibility for snow with what looks to be the continuation of a stormy pattern overall.
Wednesday will finally feature more than a glimpse of sunshine which will help boost temperatures into the 20's along with relatively calm winds. Clouds are expected to return Thursday and some light snow is expected from a clipper system Thursday night. Honestly, I had higher hopes for this system as it appears totally deprived of moisture and appears way too far north for any late coastal strengthening. Still, it will bring with it another charge of arctic cold, rivaling the Thanksgiving cold outbreak with temperatures below zero Saturday morning and rising toward 20 Saturday afternoon. Saturday will feature more sunshine however which is a welcome sight during what is the darkest days of the season.
Forecasters are watching the big southern streamer which is expected to slam the Gulf Coast with rain and thunderstorms this weekend. By Sunday evening, the storm will continue to be a sizable weather producer centered near the Carolina coast. Given the right configuration in the jet stream, this storm could make a northward turn and cripple the entire northeast with snowfall but the circumstances just aren't right this time. The polar jet is retreating and a large ridge in the jet stream is expected to build over south-central Canada just as the storm reaches the coastline. This simply does not provide a clear northward or northeastward avenue for this storm to travel and its speed is expected to slow, perhaps even stall and thus keeping the impact area smaller. Some snow could certainly fall across inland portions of Virginia and West Virginia but at this point I would be surprised to see this storm become a serious New England impact, even in southern sections though one can never say never, not with northeast weather.
As mentioned in previous posts, the jet in the Pacific will be tightening and strengthening and will force the polar jet and arctic air to go into retreat mode. This appears to be a slow process right now however for a couple reasons. First, given the time of the year and the low sun angle, it will take some time for the cold air to erode and will need some advection to do it. Secondly, the Pacific will go into full "evil empire" mode. No, we could certainly do a lot better but we've also seen a lot worse. Temperatures are thus expected to remain below freezing through at least the 12th or 13th of December. Barring a miracle from the aforementioned coastal storm, snowfall will also be minimal but there is a small disturbance capable of delivering a light accumulation this weekend.
We are likely to see a round of above freezing temperatures and rainfall sometime around the 14th-15th of the month which coincides fairly well with the peaking EPO (Pacific Jet strength). There doesn't appear to be any mechanism to provide for the return of arctic air after the 15th but the pattern doesn't appear to be terrible. If I had to guess, temperatures would likely remain above average but we might be able to reintroduce the possibility for snow with what looks to be the continuation of a stormy pattern overall.
Sunday, December 2, 2018
Cold returns in the short term but some critical questions remain unanswered for the middle of the month
We had to make a temporary retreat from our trip to fantasy island Sunday as temperatures warmed and snow changed to rain. After a balmy night, colder air will gradually regain control of the region's weather and another extended stretch of sub-freezing temperatures will commence beginning Monday afternoon. All of this has been well foretold but we have a nice addition to the incoming cold which comes in the form of a period of light snow during the day Monday. Nothing exceptional is expected but the northern Vermont high country (especially the very norther part) will see one to as much as 4 inches.
No complaints from me since I would trade snow for sun at any point during the ski season, but the sun is something we haven't seen much of going back nearly 10 days now. Our best chance for that comes Tuesday and Wednesday. I am not going to promise a lot, but we should see a few hours each day with better visibility and temperatures generally in the teens and 20's. On Thursday, an incoming clipper system should spread more clouds into the region and eventually bring some light snow. The clipper will also bring a re enforcing shot of stronger arctic cold. This means another day with some sunshine Friday, but with temperatures hovering in the teens and then approaching the zero-degree mark Friday night.
The outlook for the upcoming weekend (December 8th and 9th) revolves around a potent southern streamer which seems poised to impact some part of the east coast. In truth, most of the weekend across northern New England looks just tranquil and cold. There are hints of a weak disturbance being the catalyst for some light snow Saturday with temperatures recovering into the low 20's after a near zero start. If we get any impact from the aforementioned storm, clouds from this arrive Sunday with precipitation arriving later in the day. Vermont is on the northern end of a range of the possible impact zones but a slightly different interaction of jet stream impulses could change the look of this storm quite dramatically so I would be hesitant to write this one off so early. The polar jet will also be in the process of weakening some around this time keeping the door ajar for east coast storms to make that northward turn under the right circumstances.
The weakening polar jet and retreating arctic air comes in response to a tightening of the jet in the Pacific. This topic has been center of debate activity as it relates to the weather pattern across the central and eastern parts of North America during the middle of December and beyond that into the Xmas holiday. The European model and its ensembles show a more resounding tightening in the jet which is illustrated well when one views how the model is simulating the changes in the MJO phase and EPO index (in both cases it predicts those will turn unfavorable). In this scenario, the pattern would turn more adverse for snow and cold in a very widespread fashion. Both the American GFS and Canadian Ensembles shows considerably less tightening in the Pacific however. The pattern does allow the cold to retreat some by December 11-12th but "El Torchy" would be very subdued and arctic cold would remain somewhat of a factor. No doubt this is a hugely critical question as we head further into December. In spite of the respect I have for the Euro model, I remain optimistic we can avoid much of that outcome for now.
No complaints from me since I would trade snow for sun at any point during the ski season, but the sun is something we haven't seen much of going back nearly 10 days now. Our best chance for that comes Tuesday and Wednesday. I am not going to promise a lot, but we should see a few hours each day with better visibility and temperatures generally in the teens and 20's. On Thursday, an incoming clipper system should spread more clouds into the region and eventually bring some light snow. The clipper will also bring a re enforcing shot of stronger arctic cold. This means another day with some sunshine Friday, but with temperatures hovering in the teens and then approaching the zero-degree mark Friday night.
The outlook for the upcoming weekend (December 8th and 9th) revolves around a potent southern streamer which seems poised to impact some part of the east coast. In truth, most of the weekend across northern New England looks just tranquil and cold. There are hints of a weak disturbance being the catalyst for some light snow Saturday with temperatures recovering into the low 20's after a near zero start. If we get any impact from the aforementioned storm, clouds from this arrive Sunday with precipitation arriving later in the day. Vermont is on the northern end of a range of the possible impact zones but a slightly different interaction of jet stream impulses could change the look of this storm quite dramatically so I would be hesitant to write this one off so early. The polar jet will also be in the process of weakening some around this time keeping the door ajar for east coast storms to make that northward turn under the right circumstances.
The weakening polar jet and retreating arctic air comes in response to a tightening of the jet in the Pacific. This topic has been center of debate activity as it relates to the weather pattern across the central and eastern parts of North America during the middle of December and beyond that into the Xmas holiday. The European model and its ensembles show a more resounding tightening in the jet which is illustrated well when one views how the model is simulating the changes in the MJO phase and EPO index (in both cases it predicts those will turn unfavorable). In this scenario, the pattern would turn more adverse for snow and cold in a very widespread fashion. Both the American GFS and Canadian Ensembles shows considerably less tightening in the Pacific however. The pattern does allow the cold to retreat some by December 11-12th but "El Torchy" would be very subdued and arctic cold would remain somewhat of a factor. No doubt this is a hugely critical question as we head further into December. In spite of the respect I have for the Euro model, I remain optimistic we can avoid much of that outcome for now.
Thursday, November 29, 2018
Some milder air/rain Sunday is the only blemish on a good looking first 10 days of December then pattern may turn milder for middle of month
With the amazing month of November coming to a close, I wanted to take just a moment to savor what was one of the most stunning stretches of weather I've seen in Vermont. Some have implied that I have been guilty of some wishcasting in the past, but I don't think I would be even capable of wishcasting a month like this, even with 110-percent effort. Most of the state saw temperatures between 4-6 degrees below average, easily the coldest November of this young century and actual temperatures on the mountain averaged between 25-30 degrees depending on elevation. Most locations also doubled their monthly precipitation amounts, which is a somewhat unique element of November 2018 when compared to other unusually cold months in the November-March period. Most importantly though was of course the snowfall which was simply historic. Almost 6-feet across much of the northern Vermont high country and much of it remains firmly in place going into December. Simply driving above 2000 feet gives one a clear sense of the amount of snow on the ground right now and it's also quite a contrast to some low lying areas which saw substantially less snow this month and especially during the very elevations-sensitive recent storm.
The first half of December promises to bring a bit of everything to the region. There are certainly some signs of trouble during the middle of the month which I will try and detail as best as I can but instinct has been telling me that this will likely be one those years when many warm-ups will get thwarted and that a healthy percentage of the snow that has fallen will help anchor the base for the duration of this winter and into early spring. That's intuition talking and hopefully not too much wishcasting.
In the short term, we will get a small stretch of tranquil weather including some very limited sunshine Friday or at least some decent visibility. Temperatures on the mountain will continue to remain below the freezing mark through most of Saturday when clouds will thicken in advance of a push of milder air. Precipitation will accompany the warm front, arriving early Sunday, perhaps as a brief period of snow and then changing to freezing rain or rain with temperatures hovering right around the freezing mark and eventually rising by the evening. Much of Sunday night will feature readings near 40-degrees which means some limited melting.
Colder air and snow flurries will push back into the region on Monday and although the polar jet has yet to attain any serious strength (it typically doesn't in early December), it will nonetheless begin to have an impact on the regions weather. Snow is likely to fall from at least one clipper-like system sometime during the middle of the week. We are also operating under the assumption that the active southern branch of the jet will keep its activity further south, but this is likely to be a dangerous assumption without an overpowering polar jet so we will have to keep an eye out for that as well. The less-than over-powering polar jet will keep temperatures on the chilly side. Certainly below freezing beginning Monday night, and some single digit overnight temperatures in the middle to later part of the week. The cold is likely to get re-enforced in some fashion for the weekend of December 8th and 9th and we certainly could see some snow along temperatures readings between zero and 20.
Though the colder air is likely going to carry us through at least December 10th, there are now more declarative indications of some key changes in the jet stream in the Pacific. Specifically, that dreaded tightening which is expected to focus much of the unsettled weather on the west coast for a time and allow some of the arctic cold to retreat over the middle to eastern portions of North America. The cold will retreat from middle sections of the U.S. first and will likely linger across New England the longest but the impact stremming from these changes in the Pacific will be pretty widespread and will ultimately lead to a few milder days, even for us, sometime between December 13-20.
The first half of December promises to bring a bit of everything to the region. There are certainly some signs of trouble during the middle of the month which I will try and detail as best as I can but instinct has been telling me that this will likely be one those years when many warm-ups will get thwarted and that a healthy percentage of the snow that has fallen will help anchor the base for the duration of this winter and into early spring. That's intuition talking and hopefully not too much wishcasting.
In the short term, we will get a small stretch of tranquil weather including some very limited sunshine Friday or at least some decent visibility. Temperatures on the mountain will continue to remain below the freezing mark through most of Saturday when clouds will thicken in advance of a push of milder air. Precipitation will accompany the warm front, arriving early Sunday, perhaps as a brief period of snow and then changing to freezing rain or rain with temperatures hovering right around the freezing mark and eventually rising by the evening. Much of Sunday night will feature readings near 40-degrees which means some limited melting.
Colder air and snow flurries will push back into the region on Monday and although the polar jet has yet to attain any serious strength (it typically doesn't in early December), it will nonetheless begin to have an impact on the regions weather. Snow is likely to fall from at least one clipper-like system sometime during the middle of the week. We are also operating under the assumption that the active southern branch of the jet will keep its activity further south, but this is likely to be a dangerous assumption without an overpowering polar jet so we will have to keep an eye out for that as well. The less-than over-powering polar jet will keep temperatures on the chilly side. Certainly below freezing beginning Monday night, and some single digit overnight temperatures in the middle to later part of the week. The cold is likely to get re-enforced in some fashion for the weekend of December 8th and 9th and we certainly could see some snow along temperatures readings between zero and 20.
Though the colder air is likely going to carry us through at least December 10th, there are now more declarative indications of some key changes in the jet stream in the Pacific. Specifically, that dreaded tightening which is expected to focus much of the unsettled weather on the west coast for a time and allow some of the arctic cold to retreat over the middle to eastern portions of North America. The cold will retreat from middle sections of the U.S. first and will likely linger across New England the longest but the impact stremming from these changes in the Pacific will be pretty widespread and will ultimately lead to a few milder days, even for us, sometime between December 13-20.
Monday, November 26, 2018
Nice looking storm for the Vermont high country should yield 1-2 feet through Wednesday PM
What seemed like a garden variety event for the Vermont high country with some possible upslope-related upside has evolved into what appears to be the most exciting event for interior New England so far this season. This of course is saying alot with the three feet of snow that has already fallen in many areas. Temperatures will be marginal both Monday evening and throughout much of Tuesday but with the help of some elevation, accumulations could be very impressive and will likely give the mountains the most impressive pre-December snow-pack in recent memory.
This storm system has already left its mark on the Midwest with high winds and heavy snow and is expected to recenter itself somewhere near the New England coastline by very early Tuesday, using the relative warmth of the Atlantic Ocean to restrengthen one last time. The consolidation of this storms energy south of Vermont was not much of a question, but the rate at which this happens and where exactly does this happen has big implications for snowfall across the interior New England high country. Based on the information we have, the phasing, strengthening and position of this storm look fantastic. The coastal system will form near the southern New England coastline and track not far from Boston while strengthening quickly. Temperatures are certainly a bit more marginal than we would like, but that might only hold back accumulations for valley areas and really hurt the Champlain Valley which likely see only a minimal snow accumulation and could see more rain.
Mixed precipitation across the valleys and snow across above 1500 feet will begin Monday evening. As precipitation intensifies, I expect that all locations in the MRV will be snow, but the snow will be on the gloppier side in the valley. Higher up, any initial wetter snow should become drier as temperatures cool into the middle 20's and rain there through much of the rest of the storm. Snowfall rates appear the heaviest Tuesday morning and then will lessen to more occasional snow showers by Tuesday afternoon. Winds will be substantial at the summits Monday evening night but will gradually diminish as Tuesday progresses. We do have some lingering instability associated with this event and snow showers will continue through Tuesday night into Wednesday. The wind direction favors the far northern mountains for the best terrain enhanced snows but Mad River should scores some of this as well.
My guess on accumulations is this
8-14 by midday Tuesday
2-5 later Tuesday and Tuesday night
2-5 Wednesday - Wednesday night
Thus yielding an 84 hour total of 1-2 feet
Temperatures will remain relatively seasonable throughout the week and generally below freezing on the mountain. Snowfall should be pretty minimal Thursday and Friday and the next chance for precipitation comes in the form of snow thanks to a push of warmer temperatures on Saturday. This warmer push appears more subdued over the past few days but is still likely to lead to a period of above freezing temperatures later in the weekend into December 2nd and third. There remains a chance of some adverse precipitation types as well; but again, it doesn't look quite as bad as 48 hours ago.
As we progress further into December, the pattern looks just slightly favorable. We should get a decent push of colder weather sometime around December 4th and this chill should keep us in good hands through the December 7th-9th period. Teleconnection indices looked more mixed thereafter and the jet in the Pacific does show signs of tightening some with a large mid to high latitude ridge expected to form south of the Bering Sea. That's way out there though and I fully expect some fluidity in the outlook.
This storm system has already left its mark on the Midwest with high winds and heavy snow and is expected to recenter itself somewhere near the New England coastline by very early Tuesday, using the relative warmth of the Atlantic Ocean to restrengthen one last time. The consolidation of this storms energy south of Vermont was not much of a question, but the rate at which this happens and where exactly does this happen has big implications for snowfall across the interior New England high country. Based on the information we have, the phasing, strengthening and position of this storm look fantastic. The coastal system will form near the southern New England coastline and track not far from Boston while strengthening quickly. Temperatures are certainly a bit more marginal than we would like, but that might only hold back accumulations for valley areas and really hurt the Champlain Valley which likely see only a minimal snow accumulation and could see more rain.
Mixed precipitation across the valleys and snow across above 1500 feet will begin Monday evening. As precipitation intensifies, I expect that all locations in the MRV will be snow, but the snow will be on the gloppier side in the valley. Higher up, any initial wetter snow should become drier as temperatures cool into the middle 20's and rain there through much of the rest of the storm. Snowfall rates appear the heaviest Tuesday morning and then will lessen to more occasional snow showers by Tuesday afternoon. Winds will be substantial at the summits Monday evening night but will gradually diminish as Tuesday progresses. We do have some lingering instability associated with this event and snow showers will continue through Tuesday night into Wednesday. The wind direction favors the far northern mountains for the best terrain enhanced snows but Mad River should scores some of this as well.
My guess on accumulations is this
8-14 by midday Tuesday
2-5 later Tuesday and Tuesday night
2-5 Wednesday - Wednesday night
Thus yielding an 84 hour total of 1-2 feet
Temperatures will remain relatively seasonable throughout the week and generally below freezing on the mountain. Snowfall should be pretty minimal Thursday and Friday and the next chance for precipitation comes in the form of snow thanks to a push of warmer temperatures on Saturday. This warmer push appears more subdued over the past few days but is still likely to lead to a period of above freezing temperatures later in the weekend into December 2nd and third. There remains a chance of some adverse precipitation types as well; but again, it doesn't look quite as bad as 48 hours ago.
As we progress further into December, the pattern looks just slightly favorable. We should get a decent push of colder weather sometime around December 4th and this chill should keep us in good hands through the December 7th-9th period. Teleconnection indices looked more mixed thereafter and the jet in the Pacific does show signs of tightening some with a large mid to high latitude ridge expected to form south of the Bering Sea. That's way out there though and I fully expect some fluidity in the outlook.
Saturday, November 24, 2018
Happy early opener ! We've got a bit of everything over the next few days but we can still hope that the upcoming week is a snowy one
Happy opening day ! Skiers were greeted with a calm, crisp, great visibility morning on the single and an incredible amount of November snow on the hill. Savor this, cuz it won't happen much. We have lots of weather over the next few days and beyond. It starts very early Sunday morning as arrival of precipitation unfortunately coincides with the retreating cold. Though temperatures aloft won't be too far from freezing, models are suggesting that this warm layer is thick enough to prevent significant snow and precipitation instead will fall as rain or some freezing rain between 5 and 10 am. As Sunday progresses, the warm layer aloft will cool somewhat and the rain could mix with or change to snow, especially across the high country before ending sometime in the afternoon. The melt will be pretty minimal, but rain is rain and the November powder party will temporarily get shut down.
The Sunday weather system has a follow-up act Monday/Tuesday that has looked more and more promising. The temperatures situation still looks tenuous but I think the mountain is on the right side of this "tenuous" . Even without the influx of any serious cold, this early week weather system is a deeper one and will be supported by the development of a coastal low pressure system which will help enhance the moisture fee and stunt any significant intrusion of warm air. Models have been simulating a wide variety of accumulation totals mainly because the rate at which this storm matures remains somewhat a question. Temperatures in low lying areas will also hover at or just above the freezing mark meaning a rather gloppy accumulation below 1500 feet while a drier snow falls across the high country. Though we still have time to raise expectations some, a 4-8 inch storm is my early first guess by midday Tuesday with lesser and gloppier amounts below 1500 feet.
The Monday/Tuesday storm is supported by a pool of general instability that will allow flurries and snow showers to continue through as long as Thursday. The wind direction later Tuesday, Tuesday night and Wednesday appears light but blowing from the west, southwest which is likely to focus much of the convective snow activity on the far northern mountains of Vermont. By later Wednesday that wind direction is expected to turn and become more northwesterly allowing some of those snow showers to impact areas further south. It won't be especially arctic with temperatures not too far from seasonable levels but remaining mostly sub-freezing on the mountains while creeping above freezing in the valley areas on Tuesday, Wednesday and Thursday. Colder nights will accompany some clearing very late in the week and this should set the stage for a sunny start and seasonable start to December.
We've had it very good the last two thirds of November. Certainly one of the snowiest I can remember in a while but no good thing lasts forever. The pattern actually remains somewhat favorable through early December but there are signs of a disconcerting warm intrusion around the 2-3rd of the month which coincides with a temporary weakening of the negative EPO which has been so incredibly supportive of this recent November snowy onslaught. Cold weather is expected to return by the 4th or 5th of the month and this is supported by negative Arctic Oscillation and what we expect to be some weaker ridging in western North America.
The Sunday weather system has a follow-up act Monday/Tuesday that has looked more and more promising. The temperatures situation still looks tenuous but I think the mountain is on the right side of this "tenuous" . Even without the influx of any serious cold, this early week weather system is a deeper one and will be supported by the development of a coastal low pressure system which will help enhance the moisture fee and stunt any significant intrusion of warm air. Models have been simulating a wide variety of accumulation totals mainly because the rate at which this storm matures remains somewhat a question. Temperatures in low lying areas will also hover at or just above the freezing mark meaning a rather gloppy accumulation below 1500 feet while a drier snow falls across the high country. Though we still have time to raise expectations some, a 4-8 inch storm is my early first guess by midday Tuesday with lesser and gloppier amounts below 1500 feet.
The Monday/Tuesday storm is supported by a pool of general instability that will allow flurries and snow showers to continue through as long as Thursday. The wind direction later Tuesday, Tuesday night and Wednesday appears light but blowing from the west, southwest which is likely to focus much of the convective snow activity on the far northern mountains of Vermont. By later Wednesday that wind direction is expected to turn and become more northwesterly allowing some of those snow showers to impact areas further south. It won't be especially arctic with temperatures not too far from seasonable levels but remaining mostly sub-freezing on the mountains while creeping above freezing in the valley areas on Tuesday, Wednesday and Thursday. Colder nights will accompany some clearing very late in the week and this should set the stage for a sunny start and seasonable start to December.
We've had it very good the last two thirds of November. Certainly one of the snowiest I can remember in a while but no good thing lasts forever. The pattern actually remains somewhat favorable through early December but there are signs of a disconcerting warm intrusion around the 2-3rd of the month which coincides with a temporary weakening of the negative EPO which has been so incredibly supportive of this recent November snowy onslaught. Cold weather is expected to return by the 4th or 5th of the month and this is supported by negative Arctic Oscillation and what we expect to be some weaker ridging in western North America.
Tuesday, November 20, 2018
So long as we keep El Nino at bay, I expect plenty of snow to be on the way
'Tis
that time of year again. The days are darker and many are gloomy, the weather
has gotten continuously colder and lots of snow has already been flying across
the Vermont countryside. Though many don't share our collective enthusiasm, we
remain steadfastly proud of our affinity for winter. Without the colder temperature and abundant snowfall, all that would be left is months of
incredibly short days and an unskiable Mad River Glen. So yes, we throw out the
welcome mat for another winter season on the mountain and another season of
talking weather on the blog. As always,
its always a privilege discussing this stuff with this cohort of winter
weather fanatics, many of them skiers at MRG but plenty of others who engage in
an assortment of snow-related activities across the state.
The scary blob of red off the coast early this fall
I will
admit to harboring some rather serious trepidation about the coming winter
season through much of September. It wasn't simply the continuous stretch of
warmth that encompassed all of New England from July through September but
rather what I believed to be the major cause of that warmth. Though never
attaining any serious attention from my blogging efforts, sea surface
temperatures, regionally speaking, like within several hundred miles of the New
England coast, do play a rather significant role in the weather across all of
of New England not just coastal sections. There's some neglect to go around for
not discussing SST anomalies more often on a regional level but I don't recall
ever witnessing a time where sea surface temperatures in the Atlantic achieved
such a warm state in a relative sense. The impact was undeniable and several of
our favorite regional weather personalities made a point to mention the number
of days featuring 70-plus dewpoints or 65-plus dewpoints or the number of nights
where temperatures failed to break 70 or 65. It may not have been the hottest
summer on record, but was arguably one of the more humid summers in a
generation and perhaps more. Furthermore, coastal areas were hit with a
succession of heavy rain events, many of which caused localized flooding and
have largely contributed to well-above normal rainfall amounts for the year.
Vermont has largely avoided this and rainfall amounts of remained in the rather
ordinary range during the summer and also during the autumn months. The
anomalous warmth persisting in the coastal Atlantic Ocean waters and the
apparent feedback resulting from it, on a regional scale, caused a bit of a
fire alarm regarding my thoughts on the upcoming winter. We had to somehow rid
ourselves of this warm blob in the Atlantic or else face some rather difficult
headwinds. Fortunately, we have for the most part. Whether it be attributed to
the pattern shift in mid-October, localized storminess or localized chaos of
ocean currents, much of the warmth that
was focused along the New England coast has been swept well to the south and
water temperatures have returned to normal, and with that, we can go back to
our regularly scheduled programming.
Sept SST's
Nov SST's
What's up with El Nino
The
state of the ENSO invariably plays a large role in pre-season outlooks and
along with the aforementioned coastal Atlantic Ocean water temperatures, raised
some alarms. Us Vermont powderhounds are likely still feeling pretty wounded
after the 2015-2016 Super Nino abomination. Any talk of a coming El Nino is
thus not likely to foster much positive energy. Though those feelings are quite
understandable, large distinctions need to be made regarding various ENSO
events and the stark differences between the varying intensities of El Nino and
the overall impact it has on New England winters. The Super Nino years,
particularly the last two ('97-'98 & '15-'16) both featured exceedingly
mild temperatures and only in the former were we able to scrape out some
halfway decent snowfall. Many of the El Nino years in our recent sample size
however can be more accurately catorgorized as weak or garden variety and those
have yielded considerably different outcomes for Vermont especially on the
temperature side. The concern this year was that a weak El Nino would quikcly
evolve into a much stronger event but those concerns, just in the last two
weeks have eased as temperatures in the critical regions of the equatorial
Pacific have relaxed somewhat.
This
isn’t to say that garden variety El Nino winters or weak El Nino winters
guarantee us a season of epic ness. The many in our sample size have yielded
mixed results but one thing is clear in the aggregate, El Nino’s of the
“weaker” variety have a much more subdued impact on temperature. Furthermore, a
few in our sample size that I’ve shown below turned out to either somewhat or
even more significantly epic. The key figure to watch are those actual SST
anomaly values in the critical regions of the equatorial Pacific. If we can
keep those numbers below 1.5 C or better yet 1 C above normal then we have a
much better shot at avoiding the extended blowtorch that often accompanies stronger
El Nino or Super Nino winter seasons. Let us not forget that there is one very
positive byproduct of most El Nino, the revved up southern branch of the jet
stream, responsible for juicy southern streamers that have been known to
produce big east coast snows across both coastal areas and the interior. We’ve
already gotten one of those and we aren’t yet though November. So long as we
can keep El Nino somewhat alive there will be more to come.
In the below graph, I color coded the temperature results and then gave a verbal description of how the actual snow season was.
Watching the Pacific as always
The
next variable on our checklist is the PDO or the Pacific Decadal Oscillation. We’ve
watched this “bad boy” every year. The PDO describes the configuration sea
surface temperature anomalies across the mid-latitude more generally and
geometrically as opposed to the ENSO (El Nino/La Nina) which specifically
relates to whether water temperatures are above or below normal in equatorial
regions. At first glance, the PDO doesn’t appear to tell us a lot this year.
The last reading of .09 is pretty neutral on the scale of things. The super
+PDO winter of 2014/15 had an index well above 2 by way of comparison. That
said, water temperature anomalies, specifically in the Gulf of Alaska and over
the Bering Sea have been especially noteworthy.
The
Bering Sea water temperatures have a lot to do with the incredible loss of sea
ice in that region over the last years. Yes, some of it relates our warming
climate which has had strikingly massive impacts at high latitude regions such
as the Bering Sea. Some of it is also variability. The Bering Sea is just a
particular region where sea ice has been running especially low recently, in
other arctic regions, it has been higher. The loss of this ice however and
persistent warmth in that region has created a blob of anomalous sea surface
temperature warmth that is especially noteable. When climate scientists
attribute mid-latitude cold waves to the warming climate, they are often
referring to the altering of the polar air pathways that are induced by some of
these sea surface temperature features. In the case of this year, much of this
warmth in the Bering Sea extends to the Gulf of Alaska. If this blob of warmth
remains in this locale, the pattern will tend to favor more high latitude
ridging in western North America and troughing and general storminess focused
on eastern North America. Interestingly, this is exactly what has transpired
when this particular sea surface temperature pattern developed.
Snow and Ice expansion so far
Last on
the list of “measurable” variables is the build-up of snow and ice on a hemispheric
scale. Though one can argue on the validity of some of the inferences drawn
from using this data, I tend to be among the people that considers it an
important item to watch. We’ve seen some very healthy build-ups of snow in the
autumn months over the last 6 winters or so. A few of these winters turned out
to be pretty cold, and a few were taken over by El Torchy. The build-up of snow
actually got off to a pretty slow start this autumn but picked up substantially
in October and the final number that month was 20.06 (millions of square KM’s).
This is above the 50-year average but the lowest value since 2011. It’s
probably not a good year to use this variable as a serious determinant and
focus instead on other factors.
Any tells ?
Lastly,
I want to focus a little on any atmospheric “tells”. You know, how a seriously
flawed Texas Holdem player might act when he gets dealt a pair of kings and manages
to get the entire table to fold before any bets are placed. Mother Nature is
actually a much more skilled poker player. She might reveal a few things about
the way she might behave in advance of a winter but she can throw a bluff your
way as well and lead you straight to prognosticator purgatory. Still, who can’t
resist a game of poker with Mother Nature so lets play.
The two
things that stand out about the weather in the past 6 months is what was
mentioned above about regional sea surface temperatures in the North Atlantic.
We absolutely needed to rid ourselves of this plague and we did it in the nick
of time. More importantly, it is the way we did it. An abrupt pattern change
that allowed the weather to go from summer in Vermont with warmth and humidity
in early October to snow and very chilly temperatures in late October. Since
then the pattern has largely been driven by a very negative EPO or loosened
Pacific Jet. Long gone is any hints of an “Evil Empire” in the Pacific and this
has stood out to me and largely driven the very cold/snowy pattern in recent
weeks. Basically, we needed something overwhelming eliminate some of that problematic
ocean water on the Atlantic Coast and we got it. The EPO, the Andrew Benintendi
of variables, coming through in the clutch turning around what appeared to be a
less than mediocre winter outlook.
The actual forecast for this season
So lets
get some of that “Andrew Benintendi” into a forecast for the winter. I still
retain a bit of consternation on temperatures. El Nino is El Nino and most of
those are on the warmer side of average, even the weaker ones. If we keep El
Nino in check, the adverse effects on temperatures that we typically see in
strong ENSO winters will be negated mostly by the EPO, which seems intent on
assuming a more negative state for reasons discussed above though it will
fluctuate. When the EPO does fluctuate we are likely to see some adverse
conditions. Overall, I would still predict that temperatures come in on the
above side of average aggregating over the entire ski season but not by much.
If the forecast period begins on opening day, now slated for November 24th
and ends sometime in early to mid April, I would expect temperatures to come in
between 0-2 above average. Last year came out about +1 over the same period
which as you might remember, including both some very cold and some very warm.
Where
we should see a noticeable difference relative to last year is on the snow
side. The winter storm which slammed the eastern seaboard on November 15th,
foreshadows what I believe will be a very active winter full of juicy east
coast storms systems. The combination of the weak El Nino and negative EPO will
be the culprit for what I believe portends a stormy winter season. We have to
expect a significant slump in conditions at some point and we also have to hope
that the storm track is favorable enough to deliver us a chunk of the goods. My
expectation however is that it will, we will have an above normal snow season,
and a good ski season overall shared largely with other locations across the
eastern United States. So with that, another season begins with the earliest
opening I can remember in at least 15 years.Get after it !
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