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Wednesday, February 28, 2018

Big storm poised to slam much of East Coast, but much of Vermont is just not positioned well for the best snow

Our late-week east coast storm is now taking shape and deserves a disproportionate amount of analysis this update. It's a big storm and a challenging one to forecast and will continue to be even within hours of the event. By Thursday morning the storm will be centered over Illinois and Indiana and move due eastward into Ohio and Pennsylvania before transitioning the bulk of its energy to either the New Jersey coastline or the Delmarva. The question of where this transition occurs is one of a few critical questions plaguing prognosticators as we get closer to event time. Fortunately, I only have to answer for Vermont but the storm will have a broad impact and will likely produce coastal flooding, heavy rain flooding, high winds and heavy snow in multiple states.

I continue to hold out hope that we see a shift in some of the data. This still could occur even at the eleventh hour and the high country of Vermont would perform exceptionally well. Given the current expectations and the data available to us, we are not in the greatest position to see heavy snowfall from this storm. The biggest issue with the storm is the following. With most storms, the best areas of precipitation are found to the north and to the west of the area of lowest central pressure. This varies depending on the character of the storm and specifically on the maturation of the storm. This particular storm is expected to undergo a very early maturation across the Midwest, peak somewhat across Ohio and then have a 2nd peak somewhere off the east coast after it makes its coastal transition. The early maturation is going to allow a strong upper air low pressure center to form and across Pennsylvania and close off. A closed upper low shifts the areas of best precipitation from the aforementioned north and west of the area of lowest central pressure to the west and south of the area of lowest central pressure. Essentially it takes all the moisture and rotates it counterclockwise 90-degrees, sometimes more, sometimes less depending on the strength of the upper air low and the occlusion. Vermont will be positioned decidedly north of the big low pressure center, not a bad position traditionally speaking but bad for a storm like this. We won't be where the coldest air is and we will have a tough time getting into some of the deep moisture which is likely to be confined to the south and west of us.

Our first day of March will be cooler than the last few in February but readings are expected to remain above freezing for the most part as both rain and snow advance into New York State. The snow is expected to become heavy over parts of central and most of western New York Thursday night and some of the moderate snow is expected to make some inroads into Vermont Friday morning but mainly across the high country with marginal temperatures supporting only mixed precipitation or rain in the low lying areas. The heavier precipitation might even reach the Mad River Valley for a time producing the same elevation sensitive snowfall. Given the current data however, the best snow will fall across the Finger Lakes region of New York, the Catskills of New York and the Pocono Plateau of Pennsylvania along with other elevated areas of northern Pennsylvania. If we get northward shift in subsequent data I would raise my expectations for Vermont but right now I think its 1-6 inches across the north and 4-10" across the south. It will range from not much of anything for locations like Jay Peak to perhaps as much as 10 across for the summits of places like Stratton and Mt Snow. The Catskills of New York will also see elevation sensitive snowfall but are in a much better position to get the deep moisture and are could see 2-3 feet of snow. Given the strength of the storm, we could see some very gusty north winds Friday even if its not snowing hard. 

Most of the precipitation will be over by Friday night in Vermont and across most of the east coast by early Saturday though the mountains could see flurries continue throughout the day along with temperatures in the 30's. Sunday will feature more of the same on temperatures but perhaps a little more sunshine. Early part of next week appears dry and at least partly sunny with seasonable March temperatures and calmer winds verses the weekend.

A very substantial amplification in the jet stream still appears likely by the middle of next week and thus another east coast storm is a likely result. Once again, this situation looks just a touch more promising but will require some big secondary east coast action to occur. The initial storm, as mentioned in the last post will likely occlude deep in the Midwest and won't be good for much of anything. This is a terrific pattern for all kinds of east coast action but we obviously just need the right kind of storm. Next week marks another good chance, but likely not the last as the "cool and stormy" mid latitude pattern is set to continue at least until the middle of March.

Monday, February 26, 2018

Late week storm track shifts southward just a bit and snow potential takes a hit as a result

Got a few more days upcoming that are more typical of late March weather. Muddy roads freezing overnight only to becoming muddier roads the following day as temperatures climb yet again. This will be the case for both Tuesday and Wednesday. Tuesday appears to be the sunnier of the two days, Wednesday will have more clouds but both will feature temperatures well up in the 40's across valley locations and 30's in the high country.

The big story remains the late week storm. A weak push of colder air will try and advance into Vermont late Wednesday. A wave of low pressure associated with this cold nudge will allow some snow to enter the state Wednesday evening. Unless we can gain access the the chillier weather a little quicker, most of the snow associated with this will fall from Stowe northward Wednesday night into early Thursday with 3-5 inches likely toward Jay Peak. Mad River is probably looking at a gloppier inch or two above 2000 feet and mainly mixed precipitation across the valleys. The rest of Thursday should be mainly overcast as the storm gathers strength across Indiana and Ohio.

I've alluded to the notion that a lot could go wrong with this storm. We've got a strong blocking feature in the jet stream northeast of us, a limited supply of cold air and a potential early occlusion as potential road blocks and it appears, based on the last 24 hours or so of data, that all 3 will pose a problem. Though the storm will gather a healthy supply of convective moisture and take a hard run at the Midwest metropolitan areas, it will swerve right across PA as it encounters more of the blocking in the let stream. This would be fine by itself, but the storm is likely going to close off across the Midwest as well which will confine much of the snowfall to the east-southeastward moving upper low rather than allow the snow to advance northward into New England as it typically does. Though this is still a nice looking storm, the best snowfall is likely to occur across the states of Michigan, Ohio and Pennsylvania rather than Vermont. Still, the frontogenetics across the region aren't terrible and the airmass doesn't appear overwhelmingly dry. There have been instances where the models have grossly underpredicted the northward advance  of the moisture in similar situations. The easiest example would be the early March event from 2001 (one of the greatest snow events ever for the state) which also was powered by a very negative NAO. I am thus retaining a small amount of hope for this storm but the data over the last 24 hours was, needless to say, not encouraging. Given current model trends, this system is likely to mostly be a non event for all of northern New England and southern New England may not do much better.

All hope is not lost for big snow however (at least not yet). We didn't get the trend we were looking for on the March 2nd event but the data is a bit more promising regarding a potential midweek event next week (March 7th or thereabouts). This is a slow evolving jet amplification that will again close off a bit early across the Midwest. There's a bit more available cold air with this one however and since the occlusion is likely to occur so far north in the Upper Midwest, there will be an opportunity for east coast action as the upper low advances slowly toward the coast. Another situation with a large upside potential but shut-out potential as well.

There's been some chatter in the weather circles about the warm arctic and cold wave currently gripping Europe including pictures of snow in Rome (Not Rome, NY). This relates to much of what we've discussed about the overall pattern configuration early in March with colder temperatures favored at the mid-latitudes and warmer temperatures favored at the north pole. There is stronger evidence today that some split flow in the jet stream could produce some fun stuff as we approach the middle of the month  and at the very least should keep the snow falling across the western ski areas. The cold is expected to peak across the east coast immediately following the potential storm next week before waning somewhat after March 10th. Still no indications of extreme below normal temperatures but the first half of March should at least feature a consistent run of sub-freezing nights and temperatures struggling to reach 40 during the days.

Saturday, February 24, 2018

Forecast growing more wintry both in the near term and as we head into March

Much of the state remains afflicted with a glaring lack of snow for late February. Seems to be some cynical attitudes out there but I know Mad River hasn't given up and I certainly haven't given up which is wise considering how we roared back to life last year. There's plenty to talk about anyway with some wintry weather expected Sunday and some big storm potential for the back end of the upcoming week in the first weekend of March.

A low pressure conglomeration will approach the region tonight as a weakened area of cold high pressure tries to establish a layer of temperatures supportive for a winter storm. We are late in the ball game here and the ingredients appear to be thrown together at the last second but we are very close to a decent winter storm across central and northern Vermont as precipitation arrives Sunday morning. Temperature profiles in the lower troposphere appear to be mostly supportive of a sleet event but looking more closely, the above freezing layer, though several thousand feet thick is awful close to the freezing mark, and may be incapable of melting the snow while the heaviest precipitation is falling during the mid and late morning hours Sunday. Surface temperatures are likely to hover around the 30-34 mark (depending on elevation) but we should see a decent period of sleet and snow mixed with a period of heavy snow possible at some point before noon. The farther north you go across the state, the higher snow/sleet accumulations will be. Across the Mad River Valley, I would expect a dense 1-4 inches. It will make for a good foundation layer though I know it's a bit late in the season to care about that.

It does not look especially chilly in the wake of Sunday's precipitation mixture. With the help of sunshine, Monday and Tuesday, the last two in what has been a disappointing February will be spring-like with readings soaring into the middle 40's while dropping into the 20's at night. Wednesday should feature more clouds but similar temperatures.

In spite of the continuation of mild weather, the large block across Greenland will be building as advertised and will cause big changes in the behavior of the jet stream going into March.  The negative NAO will be aided by a negative AO and a weakened Pacific jet stream and is likely going to produce one of the more sustained stretches of wintry weather we have seen since early January. We don't have the support from the PNA however and in addition, it's March, so the intensity of the chill just won't be there. There should be plenty of discussion relating to storms however. Some will miss, some will hit but I will rather boldly suggest that the end of March could feature more snow on the ground than the beginning.

Talk of storms begins right now with a potentially big one in the works, bringing precipitation to the east coast as early as late on Thursday. The storm is expected to gather strength in the central Plains, make a direct run at some of the major Midwest metropolitan centers like Detroit and Chicago and then get forced eastward and perhaps even south of eastward as the very mighty block in Greenland puts an end to the run of warmer storm tracks. The setup has a ton of potential but remains a tenuous one. Cold air is lacking as evidenced by the warm forecast leading up to the storm. If the storm gathers strength and closes off too hard and too early, warm air could get sucked right into New England in spite of the favorable storm track. The storm might also get shunted too far south.

I can say this much as of now. If we can attain access to the healthy conveyor of moisture associated with this storm, we should get decent amounts of snow. The big accumulations might be confined to the mountains above 2000 feet but there's a very lofty best case scenario so stay tuned. The storms evolution along the east coast coast is also a question and mark and the possibility of a stall along the coast exists. Precipitation timing hypothetically speaking would involve a start around Thursday evening, continuing through Friday and quite possibly into Saturday given the right kind of east coast "stall". 

Another potential storm follows around the time of March 5th. This was part of the reason the American GFS model was suggesting 4-5 feet of snow yesterday in Vermont but data over the last 24 hours has this system well south of us. Lots of time remains however so lets wait and watch.

Biggest reason to be optimistic relates to my good friend who is the biggest snow-magnet I've ever seen in my life. Every where he goes, mother nature delivers 3 feet. He plans on arriving in Vermont late Friday.

Thursday, February 22, 2018

Won't get much help from the precipitation producers this weekend, could be a different story late next week though

It was El Torchy extraordinaire on Wednesday as historically warm temperatures encompassed the entire east coast including Vermont. Readings were well into the 60's way up on the mountain and touched 70 in a few spots across the low lying valleys. The excessive warmth was the result of a ridge in the jet stream which could rival conditions one might see in a summer. That ridge has been beaten back somewhat as of late this week and will continue to gradually diminish in the days to come. Needless to say, the Vermont snowpack took quite a hit and the northern part of the state missed out on some surprise snowfall that impacted parts of central and western New York and parts of Massachusetts.

Active weather will continue as subtropical moisture feeds a rather intense clashing of air masses as we enter the last full weekend of February. Tough temperatures have returned to below freezing levels, the area of cold will become stale as precipitation arrives from an innocuous area of low pressure that will pass to the region's northwest. Sleet should arrive during the afternoon across much of the central and northern part of the state and will change to a period of freezing rain during the evening. The precipitation won't amount to much and most of it will end by Saturday morning. The rest of Saturday appears balmy yet again, perhaps not the 60-degree kind of warmth we saw Wednesday but readings should climb into the 40's and the clouds should give way to some blue sky as the day progresses. A low pressure area of more substance will bring clouds back into the region Saturday night. As this is happening, a very minimal amount of cold air will drain into northern New England from the northeast. Though the primary area of low pressure is expected to track to our northwest again Sunday, severely denting our chances at significant snow, the subtropical connection will help a new area of low pressure to form along the southern New England coastline. Though we won't see the big snow, as mentioned, temperatures are likely to remain close to the freezing mark with a mix of wintry precipitation beginning Sunday morning. My guess right now is for a brief period of wet snow Sunday morning followed by some sleet, freezing rain and some rain, especially in the Champlain Valley. The mountains are likely to finish the the weekend with more "white" than when they started, but it will be sloppy and you'll have to head pretty far north to get out of that "slop".

The early part of next week through Wednesday March 1 appears milder with readings up around 40 during the day and in the 20's at night. Aside from some flurries in the northern mountains Monday, these days appear tranquil with decent amounts of sunshine both Tuesday and Wednesday. Then it gets interesting. It always seems to  happen when a big Greenland jet stream blocking feature enters the ball game and that's exactly what will transpire as we approach the first full weekend of March. A storm will approach from the west and like its predecessors, will head fake a Great Lakes -> Canadian province track. Not this time however. The blocked jet stream across the Davis Straits and Greenland is likely to force the storm south and perhaps really hog-tie it to the Atlantic Coastline. That's where all the craziness could ensue with all kinds of precipitation along with wind and coastal flooding. There is a glaring lack of arctic cold available but it doesn't appear excessively mild either.  So long as Vermont attains access to one of the storms moist conveyors, we should be able to get a decent elevation event at the very least. The blocking across Greenland is very severe however and is certainly capable of suppressing all of the precipitation to the south.

The storm late next week, wherever it goes, marks a general shift in the jet stream personality across not only North America but a large portion of the Northern Hemisphere. By the time of March 5th, the pattern will favor cooler weather across middle latitude locations and warmer conditions across the high latitude areas. Not a bad looking set up for March skiing not only for Vermont but also out west which has finally turned the corner in recent weeks and has gotten some decent snow. Vermont just needs the precip in March. If we get it, we should see some snow and perhaps significant amounts of it, if the jet sags too far south, it will mean a rather useless stretch of cooler weather.

Tuesday, February 20, 2018

Pattern to become gradually more supportive of snowfall after Wednesday Feb 21, but only slight chance we get some first aid by the end of weekend

El torchy has managed to get its hands on the state of Vermont. Some of the rainfall that's impacted the northern half to third of the state will push northward Tuesday night and allow for some limited sunshine Wednesday. This will allow temperatures to reach the excessive levels that many have already seen in the forecast. Even at the base of MRG, readings are likely to reach 60 while temperatures reach the 50's even across the high country. Though the corn horn will surely be sounding, the combination of winds and the excessive temperatures are sure to put a massive dent in the snow pack by Wednesday night. A strong cold front will allow some modified arctic air to drop into the region by early Thursday and temperatures are expected to be well below freezing as a result (20 degrees).

The weekend forecast has gained a bit of intrigue but we aren't where we need to be just yet. The strong Nina-like southeast upper ridge will still be a major player, but the falling NAO index is seeking to be part of the weekend equation and will likely keep El Torchy at bay somewhat. Subtropical moisture is also expected to be involved in what appears to be two garden variety precipitation producers. The decaying of cold weather will still be in place Friday and may allow for a period of snow or mixed precipitation Friday afternoon before precipitation ends as rain or a bit of freezing rain depending on your location Friday evening or at night. Saturday will then become mild though readings should stay in the 30's and 40's this time while a 2nd storm system gets better organized in the southern Plains and tracks northeastward toward the lakes. This 2nd system has virtually not cold air to work with at the start, but a limited amount of Canadian chill could get entrained into the storm if the storm's energy makes a decisive transfer to the Atlantic coast. Models weren't especially keen on that idea Tuesday afternoon but it remains a possibility. As of now, rain, mixed precipitation and snow could all happen Sunday and though the chances of significant snow remain small, it does exist.

Temperatures are expected to remain on the milder side of average through early next week and thus the remainder of the month but the excessive thawing will be over. Readings will generally be in the higher 30's Monday and lower 30's Tuesday. We will be watching some sort of storm, hopefully a strong one for later in the week. The big southeast ridge will be almost dead and by that point the negative NAO will begin driving the pattern for a time. We don't want to kill the warm ridge off too quickly or we might just see a suppressed storm track later in the week. Additional storms are likely in the week to follow but the question will revolve entirely on the track.  Without the support of the PNA and only a slightly weakened Pacific Jet, the temperature outlook early in March doesn't look especially cold; in fact, it may not even be below average but the pattern does support snowfall given the right storm. 

Sunday, February 18, 2018

A big push of spring-like warmth is on the way

All things considered, Vermont ski country managed to do decently well this holiday weekend. Our massive spring-like wave of warmth is coming however and it would be accurate to refer to it as "warm" as opposed to "mild". Temperatures will be near 20 to start our 2018 President's Day Monday but gradually warm past the freezing mark as clouds advance into the region. By the time precipitation arrives in association with this formidable warm front late in the day Monday, temperatures will be up around 40 and rain will be the result. For much of Monday night into Tuesday, the aforementioned front will remain situated in close enough proximity (roughly the Canadian border) to keep the showery weather and clouds close. Rainfall will be more prevalent, the farther north you are in Vermont but the Mad River Valley and most of the rest of the state will be decidedly in the warm sector. This means temperatures make a push into the 50's Tuesday and the corn horn gets blown. Wednesday appears downright tropical. The surge of warmth makes another northward push allowing for a good amount of sunshine to mix down some of the excessive mid-level warmth. Readings are likely to reach 60 even at the base of MRG (1700 feet or so) and well into the 60's across the low lying valleys.

A cold front will put an end to the spring extravaganza Wednesday night and will bring a few showers to the region as it does so, though heavy rain is not expected. Temperatures will remain well above average and in many areas, above freezing Thursday but will finally cool into the 20's Thursday night thanks to a clear sky and calm winds. Friday appears quite sunny for much of the day with temperatures approaching or crossing the freezing mark but clouds in advance of the next storm system may make an appearance at some point before evening. This weekend weather producer has more subtropical juice and only a minimal amount of cold weather. Most importantly, models are concurring that it tracks up through the central or eastern Great Lakes. Precipitation may start as a mixed bag early Saturday and then change to ice and rain as the day progresses. It would be wise to leave some leg-room for changes as we get closer to the weekend but the prevailing weather pattern is quite mild which encourages these types of storm tracks. Saturday's precipitation might also not be the last of the weekend weather though it is tough to tell as of now what type of storm might follow, if at all for Sunday or Monday.

Changes in the jet stream are expected to occur on time and a block is expected to form close to Greenland by early next week. This will put an end to the excessive temperatures across eastern North American generally but readings will only slowly drop in Vermont. Temperatures are likely to spend a chunk of the last weekend in February above freezing and this might continue into Monday and Tuesday. The February 28th/March 1st time frame is finally when we get our first legitimate shot at some new snow but arctic air appears to have a very minimal presence over New England and any day where precipitation isn't falling, temperatures are likely to climb above freezing.

Thursday, February 15, 2018

We get a quick burst of winter this weekend, but mild weather is expected to dominate the region generally through February 26th

There is some improvement way out on the horizon around the time of February 26th or so thanks to the development of a block in the jet stream across Greenland which will help turn the NAO negative. Until then, the pattern continues to appear extremely adverse, bringing back the painful memories of the blowtorch we saw at the end of February last year. The warmer temperatures will soften snow conditions Thursday as readings rise into the 40's. The short term forecast also has northern Vermont avoiding much of the rainfall, which will be prevalent across southern New England Thursday night up to about southern Vermont. MRG will likely see a bit of light rainfall Thursday night, but an arctic boundary arrives by early Friday and will end round 1 "El Torchy" and the chance for any rainfall.

The burst of wintry weather arrives in time for the upcoming holiday weekend. The arrival of the cold will be accompanied by a short window where both low level instability and prevailing winds are favorable for snow showers from the Mad River Valley up to Stowe. We should see snow showers and a few snow squalls for a few hours on Friday across the high country. Accumulations will be limited by the time skies clear Friday night, but the mountains could see 1 to as much as 4 inches. Saturday is a seasonable day with diminishing winds and about as bluebird and bluebird can get. We won't be able to brag about the snow pack but I do appreciate those rare days in the winter where we can get great views of both the Adirondacks to the west and White Mountains of NH to the east.

More subtropical moisture will help generate a storm that will quickly track from the lower Mississippi Valley up toward the Virginia tidewater Saturday night. Unfortunately, there are no indications that the storm will track farther north and this means northern New England misses out on significant snowfall. There are indications of some and its still possible we end receiving more since these systems do have a tendency to make a late-inning northward shift, but as of now it looks like a light accumulation of 1-3 inches Saturday night into early Sunday. The rest of Sunday will actually feature a decrease in cloudiness with temperatures reaching the freezing mark late in the day.

Sub-freezing temps continue through Sunday night before balmy temperatures flood the region Monday. The Euro was leading the charge on what appears to be a very intense late February torch. Other models are now falling into line by showing a 3-day stretch of spring-like warmth. Without the help of some cooling and clouds from Quebec (which appears less and less likely), we could see readings well into the 50's Tuesday and even 60 in the valley locations. A cold front will end the 2nd round of El Torchy Wednesday but readings are likely to be up around 50 at least early in the day. Some rainfall is expected with the arrival of the cold front Wednesday though there are no indications of a heavy rain event; nonetheless, the thaw will be damaging since snow conditions are already thinner than we would like.

Though temperatures will cool toward the end of the week, another push of relative warmth is expected around the time of the last weekend of Feb. It's too early to tell what type of weather will manifest but at the very least, temperatures will remain above average and likely above freezing for at least one day. As mentioned above, the changing NAO should help bring about a more sustained stretch of more seasonable temperatures around Feburary 26h though there are no indications of arctic chill or below normal readings. I can't promise when and if any big snowfall returns. The pattern will certainly improve by the time we hit March but at face value it looks dry for New England though that prognostication doesn't mean much this far out.

Monday, February 12, 2018

Outlook for holiday week turns even milder

The late surge of warmth on Sunday has our snow encrusted yet again and when combined with the outlook for much of the rest of February, my Valentines Day spirit leaves something to be desired. A ferocious ridge in the mid-latitude eastern Pacific will induce a fast flowing west to east jet stream south of Alaska. Not only will arctic air be forced into retreat mode across eastern North America, but the pattern will take on a classic "negative-PNA" configuration which focuses all the cold weather and much of snowfall on the Intermountain West while large portions of the eastern United States experience spring-like warmth. Models have been and continue to be extremely slow picking up the intensity of the pattern which largely stems from the stalling MJO and problems resolving the behavior of the jet stream in the Pacific generally. There's simply no denying it now however, the upcoming pattern is a very challenging one and is almost certain to deliver Vermont its third consecutive February with temperatures 3 or more above average. Barf  !

Seasonable temperatures and sunshine will prevail for Tuesday and temperatures will remain winter-like through Wednesday morning before "El Torchy" makes its first February visit to Vermont.  The warm push will not bring any new snowfall to the region prior to its arrival; instead, southwest winds Wednesday afternoon will bring temperatures into the 40's in many areas and 30's across the high country. This initial round of warmth, which is now expected to persist through early Friday doesn't appear to be associated with heavy rain or high dewpoints which are two ingredients that eat snow like we might eat fried green beans after a long day at MRG. We will however have one relatively windy day Wednesday, 48 hours of above freezing temperatures in many areas and some light rainfall Thursday, Thursday night and early Friday.

Arctic cold is set to return for a time beginning midday on Friday and a sagging front responsible for the colder weather does offer a few more hopeful possibilities. The most likely outcome is that some light rainfall early Friday gives way to a sharp turn toward colder temperatures accompanied by a few significant snow showers. Though the window is brief, the set up for lake/terrain induced snow showers is pretty good across the Mad River Valley Friday evening as it stands right now and a few inches is a reasonable expectation by early Saturday. Then there is the Tom Brady hail mary possibility for Friday. This would involve Friday's potential precipitation producer becoming an anafrontal wave with undercutting southeastward advancing cold inducing a changover to steady and significant snowfall. Models don't show this now and thus it has the distinction of being a Tom Brady hail mary.

 Our upcoming holiday Saturday is sunny and chilly, hopefully with a few new inches of snow and this is followed by a cloudier Sunday with temperatures making a run at the freezing mark by the afternoon. By Sunday, milder air will be gathering across the southern and central parts of the country and preparing to make another massive push northward. We could see some precipitation, even the more frozen type prior to its arrival, but unfortunately,  it will be very difficult to keep the milder air away from the state for a good chunk of the holiday week. The mild push stems from what is expected to be an amplifying jet and a huge dump of cold across the western United States. We can get somewhat saved if the jet turns out to be flatter. Though this remains a possibility, it seems to be a deteriorating one as more and more model data continues to support the negative PNA configuration mentioned above. Mild weather would thus reach the state Monday, Presidents Day which would be one of up to 3 or 4 above freezing days next week. Rainfall is also possible. The forecast isn't solidified yet and there have been 2 or 3 other potential thaws that have been thwarted this winter but the fundamentals look worse and worse.

Out further in time is the potential development of a block in the jet stream over Greenland. Though this would help push the jet stream southward again and possibly allow the month to finish with a flourish, ensembles continue to push the positive impacts of this feature out further in time.

Saturday, February 10, 2018

Pretty good first 10 days of February but these next 10, not so much

Temperatures climbed into the 30's rather quickly across Vermont Saturday and the best snow was confined to far northern portions of the state. Colder air will make a slight push southward this evening, undercutting a very warm ridge in the jet stream positioned along the east coast. Mad River is right on a west to east running line dividing mixed precipitation and rain to the south and snow to the north this evening; but needless to say, additional snow accumulation is more likely farther north, especially from Stowe northward to Jay. For Sunday, much of northern Vermont is situated between the two conveyors of moisture associated with a disorganized storm. The cold conveyor and much of the wintry precipitation will be confined to the St Lawrence Valley, the warm conveyor and the rainfall will be confined to the southern half of New England mostly and points south. Temperatures are expected to fall back below the freezing mark tonight at Mad River and sneak back above the freezing mark by Sunday evening. Aside from some freezing drizzle, light freezing rain or just a little bit of plain light rain, I don't think we see too much action tomorrow. It's a little frustrating the way this storm turned out, but the dominant ridge in the jet stream mentioned above was simply too dominant this weekend and greatly hindered our results.

The outlook going forward is even more frustrating and getting close to the soul crushing category at least for me. The stalled MJO turned out to be a big head scratcher this month and has allowed the jet stream in the Pacific to clench its fist yet again. A few days ago, I might call the issue mildly problematic but with each round of new data, the ridge in the mid-latitude eastern Pacific looks more prominent and its going to pose some substantial challenges for us as we head toward the holiday week. The all important Arctic Oscillation (AO) will add some very unnecessarily gasoline to the fire during the upcoming week but will again turn negative (we think) around the time of the holiday week, keeping a glimmer of hope alive. The North Atlantic Oscillation (NAO) which has been invariably positive throughout the winter is then expected to take a significant negative turn after February 20th providing some more hope for the end of the month. I am not going to lie however, these next 10 days or so do not look great right now and it's hardly the best time for mother nature to smack us with a few upper cuts. 

Seasonable temperatures will build back into the region Monday and temperatures will fall back into the 20's and then into the single numbers Monday night. Tuesday should be a beautiful blue bird February day with calm winds and plenty of sunshine. Clouds will advance into the region late in the day as mild Pacific air makes a massive push toward Vermont for the middle of the week. The mild air will successfully reach the state by Wednesday but before it does so, we could see some accumulating light snow either Tuesday night or very early Wednesday.  Late Wednesday into Thursday looks like a torch with mild winds and some sunshine pushing temperatures toward 40. Readings will then stay mostly above freezing Wednesday night and get even milder Thursday.

Cold arctic air is still expected to make a push southward on Friday February 16th and this ensures a cold start to the holiday weekend. Unfortunately there isn't much fundamentally in the pattern keep the cold in place. Some snowfall is possible as the cold air advances into the region Thursday night or Friday with drier weather more likely Friday night into Saturday. Mild air is then expected to begin pushing into the region as early as Sunday. Can we at least establish some sort of overrunning surface to allow for some snowfall on Sunday ? Certainly possible, and it's about the best we can hope for. Lots of mild air will again build across the Mid Atlantic states and it be difficult though not impossible to keep it from reaching Vermont at some point in the Monday Feb 19th (Presdident's Day) to Wednesday Feb 21st period. Though the jet stream structure looks less than ideal, it mostly results from an amplification that is expected to occur in the western half of North America. A flatter jet stream would yield much better results and we need to hope to see a trend in that direction over the next few days.

Thursday, February 8, 2018

Powdery snow conditions persist through early Saturday but weekend will likely finish with mixed precipitation

Over 20 inches of snow in the past week has created some of the best snow conditions of the year across the state. We can expect a bit more as well during the early part of the weekend as another conglomeration of active weather systems, with the help of more subtropical moisture approaches the region from the southwest.

We can expect flurries to accompany the bearable winter chill during the day Thursday with some limited sun followed by a relatively dry Friday (with the exception of a few flurries). Temperatures will be in the teens for the most part Thursday and rise into the 20's by Friday. The active weather mentioned above will arrive sometime Friday evening with the approach of a warm front. Light snow will overspread the region from southwest to northeast and continue for a better part of the overnight and into early Saturday. Though a big accumulation isn't expected, 2-4 inches along with 20-25 degree temperatures should ensure a powdery Saturday morning. Readings are then expected to make a push toward the freezing mark during the afternoon and although periodic light snow may continue, snow conditions are expected to get a little wetter.

The forecast then gets tricky for the latter half of the weekend as a more significant area of low pressure with a more impressive area of moisture approaches the region. Models have had a very difficult time assessing not only the track of this system but even its overall viability. Unfortunately, it accompanies a strengthening ridge in the jet stream along the eastern seaboard and mild air which will begin to make a push into the region later in the day Saturday will continue its push with the storms arrival Sunday. The cold air in eastern Canada, which has proven to be invariably formidable throughout the winter will continue to push back and is likely going to save Vermont from a significant thaw. I want to leave room to alter the outlook somewhat but it appears as if Sunday's precipitation producing low pressure area will pass right up through central Vermont or just to our south. There's a lot of mid-level warmth however and snowfall on Sunday will be a tough ask. We will need the storm to track at least 100 miles further south for that; still, this will allow northern part of the state to avoid the period of plain rain. A period of sleet and freezing rain is probably the most likely outcome Sunday and what is even more likely is some small changes (at least) in these expectations.

Cold air will make a temporary re emergence over New England for Monday but the middle part of the week continues to look milder. The array of model data Thursday morning was somewhat less mild during the middle part of next week verses some data released in prior days. This has been a repeated theme throughout the winter that we can actually be thankful for. Even when the pattern has supported generally milder temperatures, cold arctic air has held very firm in central and eastern Canada and has mitigated the impact of several milder periods. Hopefully this occurs again next week but it continues to look as if we can expect 1-2 above freezing days and at least some mixed precipitation. Some of this cold arctic cold in Canada will make a push southward as we approach the holiday weekend. Friday of next week and at least half of the holiday weekend look chilly and I expect at least some new snow to accompany the colder weather.

The cold air is expected to relent by President's Day if you believe the ensemble data, which quite honestly have performed quite miserably beyond 10 days. We have a nice backbone of support from the AO which is expected to become modestly negative (after a brief positive interlude next week) but the pesky jet stream in the Pacific is tighter than we would probably like it and thus the signal across much of the eastern U.S. is milder than average though not overwhelmingly so. Most of the milder weather stems from the notion that a jet stream trough is expected to set up shop across the eastern Rockies. Boy do they need it since they have had a miserable stretch of snow conditions (at least the southern Rockies) dating back to late last year. I am not ready to say it quite works out as such however and I continue to think the cold in central and eastern Canada will be a factor across northern New England. Lots of hedging I suppose, but I remain on the somewhat optimistic side for the holiday week in spite of the less than optimistic ensemble data.

Tuesday, February 6, 2018

8-14 inches of the good stuff on Wednesday and Wednesday evening and awesome start (at least) to upcoming weekend

We had a storm back in the middle of December that delivered just over a foot to many of the ski areas in northern Vermont. Aside from perhaps that, the upcoming snow expected for Wednesday and Wednesday evening will be the best dose of the year so far. There is nothing especially noteworthy about the storm, it looks like a very average front loaded over-runner, but the expected track up through northwest Connecticut and eastern Massachusetts is about as good as it gets for Vermont snowfall; in addition, the region has a history of performing quite well in these setups. The snow should start rather early Wednesday, like around 9 or 10 am, accumulate 1-2 inches by early afternoon and 3-5 inches by lift closing time. Snow will continue well into the evening and taper off to flurries well before dawn arrives Thursday. Total storm accumulations will be in the 8-14 inch category and temperatures will generally be in the teens while snow is falling. Flurries will and even a few snow showers will continue for a good part of Thursday along with a stiff west or northwest wind. Combined with temperatures between 10 and 18, wind chill readings will be a shade below zero but we've seen much, much worse this year.

Moving along, we have an interesting situation brewing for the weekend. With each passing storm, it appears as if the subtropics are willing to provide more and more moisture and such will be the case this weekend. Though we'll have a healthy amount of cold air in place to start the weekend, the chill will loosen its grip on the region as we advance from Saturday to Sunday and will create a rather tenuous situation by Sunday. In spite of all this, this will likely be the best skiing weekend so far this year in Vermont. The storm in question has lots of the aforementioned moisture to work with and should come at us in a few waves. Overrunning precipitation in the form of snow could arrive as early as Friday evening and should  provide much of Vermont with powdery snow by first tracks time Saturday. Snow might be on the lighter side but could continue through at least part of Saturday. Atop the snowfall this week, it could make for an awesome day on the hill. A more significant area of low pressure will then get organized and take a run at the region Saturday night. It will bring a stronger push of milder air with it and is likely to bring more snow which could change to sleet or freezing rain. The track of this storm remains a question however and the door is open for a shift that could lead to an epic weekend of snowfall or a change to a brief period of rain. Above freezing temps, were they to occur, are likely to be a problem later in the day Sunday. Again, the weekend as a whole looks pretty good and still has a chance at greatness with a little help.

What doesn't appear great is the continued warming trend the longer range ensembles keep displaying around the middle part of next week (Feb 13th to Feb 15th). The weekend storm will be followed by a temporary push of arctic chill and perhaps some snow showers on Monday. By Tuesday, milder temperatures are expected to overtake a large expanse of the eastern U.S. and continue to push northward on Wednesday, February 14th. All of this is in response to a jet stream that looks a lot tighter in the Pacific and a lot less amplified over North America. Even the Arctic Oscillation, which models had projected with seemingly high confidence to stay negative through the first half of the month, will actually go positive for a time next week. As a result, we are likely going to get hit with a 1-2 day stretch of above-freezing temperatures and quite possibly some rainfall on Wednesday or Thursday of next week.

Beyond this troublesome stretch in the outlook, we should see some improvement. The MJO, though relatively stalled in a relatively neutral phase, should begin slowly progressing to a more favorable one allowing the jet in the Pacific to loosen again. The arctic oscillation which will move briefly positive next week is expected to go negative after that. Way too early for promises of glory but the holiday weekend does look potentially wintry with a decent chance of that continuing into the ensuing week.

Sunday, February 4, 2018

Superbowl storm produces some, Wednesday storm to deliver more and maybe another around Feb 10-11

A couple hours of moderate to heavy snow during the Superbowl this evening will get us just a little  closer to the promised land. Though this event will not be especially memorable, moisture from the storm does look a little better verses some earlier expectations and even the few hours of heavy snow should be capable of delivering at least 6 inches. Temperatures will hover at or just below the freezing mark Sunday afternoon and evening and then fall back into the high teens by Monday morning. In addition to the snowfall Sunday evening, there remains a brief window for terrain and lake enhanced snow early Monday. It all makes for a powdery Monday with a storm total of about 6-12 inches.

Flurries and snow showers will persist as mentioned during the first half of Monday but sunshine should break through during the afternoon and the evening and night should feature starry skies and single digit cold. A weakening disturbance in the jet stream is expected to bring clouds back into the region for Tuesday along with some very light snow. Though the snow could coat the ground again, the focus will be on an excellent looking storm system that is expected to bring its snow on Wednesday.  This is a very run-of-the-mill weather system, but its also one of those positively tilted overrunning front-runners that Vermont typically performs especially well on. The track of the system is expected to be close to perfect so lets hope for little change and if we go with the assumption of little change, we will see snow throughout the day Wednesday and a solid 8-14 inches by first tracks time on Thursday. I can't guarantee all this just yet, but it looks very good as of Sunday afternoon. Temperatures will finish out the week on the chilly side but readings will not stray too far from seasonable norms with temps warming into the 20's during the afternoons and falling into the single numbers at night. Aside from a few flurries, the end of the week looks fairly dry.

Moving along to our 2nd full weekend in February, there's yet another storm and it again looks somewhat promising. Lots of disagreement still persists on how the details will all shake out, but yet again, we have a bit more feedback from the subtropics, just enough cold air and a favorable enough jet trajectory. This said, it's a tenuous set up and it could all fall to pieces quite easily.

As mentioned a few days ago, ensembles have really backed off on the idea of mid-February cold. The MJO looks stalled in a relatively neutral phase and the jet stream in the eastern Pacific appears tighter than a lot of us forecasters had expected maybe a week ago. The outlook on temperatures for the week leading up to the all important President's day holiday appears substantially less cold as a result. I would be hesitant to call it mild just yet but readings are likely to move to the above side of normal and this includes a few above-freezing days. This said, there aren't any signs of a massive thaw or significant melt-off; in fact, we are likely to score some additional snowfall somehow though we are a bit more at risk for some icing or even a minimal amount of rain.

Overall, still a pretty good outlook.

Friday, February 2, 2018

A rather excellent outlook for snow over the next 5 days from two separate storms

Winter is back ! More than anything else, it's nice to see some over-performance on snowfall, which we finally saw a bit of Thursday night into early Friday. We obviously have more snow to look forward to so lets get right to it. We have the remnants of some Pacific Northwest energy that will combine with a bit of subtropical moisture Saturday night and some snowfall will be the result for a good part of Sunday and Sunday night. This storm isn't exactly a world beater somewhat of a cynic as to much of Vermont ever getting into a seriously good conveyor of moisture.  The storm will strengthen slowly however with an elongated area of low pressure passing right over the state very early Monday. Some light snow will begin across the region as early as Saturday evening and continue sporadically through Saturday night. The steadier stuff arrives on Sunday and we should see snowfall at mostly a light, but occasionally a moderate intensity through much of the day. Temperatures will start the weekend at or below zero, warm to about 20 Saturday afternoon, hold steady Saturday night and then make a run at 30 Sunday. This means that some of the snowfall, particularly in the valley areas will be a little wet. Their is a short window of time Sunday night for some terrain/lake enhanced snow before a blustery Monday with temperatures back in the teens. I would put total snowfall in the 4-8 inch range right now.

There is a small chance for some very light snow on Tuesday but the early part of the upcoming week is expected to be free of significant snowfall and should include some sunny interludes (particularly Monday).  Our midweek storm (Wednesday) is looking very promising right now, potentially one of the best so far this year. This system is another product of some active weather in the Pacific Northwest, but it should gather moisture from the Gulf of Mexico with more success than its predecessor and advance northeast as a more significant snow producer. Disagreement persists regarding the track of this storm and this will ultimately determine snowfall amounts. The Euro is tracking the system through northern Vermont while other models track the storm closer to the southern New England coastline. The northern track involves a stronger storm but introduces the possibility of a turn to sleet/ice. This goes along with some of the themes discussed in early posts regarding our flirtations with danger. The consensus of data would suggest a decent hit right now so I think optimism is justified.

A clipper system very late in the week will bring the possibility of additional light snow before another burst of cold arrives on the scene late on February 9th (Friday) or on the 10th (Saturday). The cold is expected to modify somewhat quickly over the weekend but the jury is out if this modification is accompanied by any additional snowfall.

The longer range has gotten a little bit cloudier over the last two days. Many forecasts had the middle of February pegged as another time frame where some very cold weather could hit the eastern half of the United States. These assumptions were largely based on extrapolations folks were making about the MJO. Ensembles, pretty much all of them at varying degrees, have thrown a monkey wrench into that notion and are showing the MJO stalling in a more neutral phase as opposed to continuing into a cold one. Ensembles are also indicating much warmer weather for large portions of the country. I have no issue with this, for now, but the trend has been a little disturbing and to be completely honest I would like it to stop. Assuming it does, I think we turn out fine. Perhaps not as cold as some of my own expectations a week ago but well-positioned for some additional snowfall even if the regions such as the Ohio Valley and Mid Atlantic turn mild. The aforementioned period involves the week leading into the President's Day holiday.