Think Snow, Tweet Snow !!!

Tuesday, January 31, 2012

Ugh, two potential storms look dead

During the last update I had actually tried to reign in my excitement over what I thought could be an epic three weeks on the single beginning in early February. It was a very enthusiastic but non-specific update a few days ago. At that time models had indicated upwards of 4 significant snow events in a 10-12 day stretch. Within a day of that update, models had eliminated almost all of it and indicated a weather pattern not nearly as productive. I try really hard not to get overly theological regarding the "kiss of death" and then something like that happens and suggests that perhaps I would be better served blogging about the inevitable "doom and gloom" of this winter.

Is it really that bad ? No. We still only expect one "thaw" day Wednesday before temperatures turn colder but we lost the shot at a storm late in the week. Much of that energy will get held back in the western plains and that is where some of our problems begin. The failure of that system to phase with some of the incoming polar energy this weekend creates a disjointed jet stream rather than a clearly amplified pattern. When the western plains storm finally ejects itself into the Midwest, it will get shunted southward by a polar jet that will have already played its hand.

Overall though the pattern will be highly "blocked" for the next two weeks. The ridge across western North American will develop as advertised and allow a continuous throng of cold shots into New England to keep it wintry (although models have backed off on the intensity of the cold). Snow-wise however we are probably a week or so away from a potential powder producer. The weekend should stay mainly high, dry and seasonable. Not a bad one to be outside but at this point I would expect little or no fresh powder. By the middle of next week we should have a clipper that could yield some of the good stuff. This will be followed by a surge of colder temperatures and potentially a more organized storm system prior to the weekend of the 9th and 10th.

Still a relatively good stretch of weather, but I want more and am not happy with the way things are trending.

Sunday, January 29, 2012

No more consolation prizes, pattern looking golden by the weekend

It is now just a few days away. A few days and things should really start to get interesting at MRG. Two months of trying to make the most of a mostly lousy weather pattern and finally as we move toward February the stars align. The jet energy across the Pacific Northwest will undergo a complete collapse over the next week allowing a large ridge to develop across the western United States. Even better, this ridge will extend northward over western Canada right along 135 west ultimately reaching the polar regions. It is a development that should make us ecstatic since not too many weather features can make me as happy. The ridge across the west will eventually combine forces with another large ridge across over Greenland. Hopefully, the whole thing just turns into one big "high latitude block party". All the cold and snow can descend into the mid-latitudes and do so for an extended period of time.

There is a lot of potential over the next 2-3 weeks. Clippers, East Coast bombs, Gulf of Mexico monsters. We have the potential for all of it and we have earned it since we have certainly done enough time in the can this winter. I won't get too specific with this update. There is some powder to ski Monday and the push of warm air Wednesday will have an inch or two of snow preceding it on Tuesday. The Wednesday warmth however is a one day event. One afternoon of above freezing temps before the talk shifts to snow and eventually cold. Our first potential storm comes from a southern Rockies weather system that will push through the Midwest Thursday. Models are all over the place with this system. The Euro shows a nice hit Friday for most of Vermont but there are a few contrary opinions. As this new and much more amplified weather pattern begins to take shape over the weekend of the 4th and 5th, the chances for powder start coming from everywhere and very frequently. For example, several model runs have a Gulf of Mexico low pressure area blowing up and evolving into a massive snow producer in the Sunday/Monday time frame. Additional reenforcing amplifications throughout next week will provide more snow possibilities. It should be a good time to be alive in Vermont so as Bob Dylan used to say get busy doing it.

Thursday, January 26, 2012

Nice stretch of winter starts around February 3rd

Rain on top of the freezing rain/sleet on top of a few inches of snow is the process by which concrete is made, or at least that is how I learned it. The 3-inch concrete slab is not exactly ideal when its plastered on top of 40 inches of powder. We don't have 40 inches of powder though so the concrete slab could be the start of the long road back.

Wintry weather should return for the weekend although temperatures will remain on the mild side Saturday. As mentioned in the last update, an eastern North American trough amplification will interrupt the mild pattern for a few days and embedded within this trough are two impulses capable of delivering the mountains some snow. The first rotates through the Great Lakes Saturday and spreads snow showers in the Green Mountains Saturday night. This particular weather feature is probably good for a 1-3 inch dust up but it will drop temperatures back into the 20's for Sunday (from the 30's Saturday). The second feature looks like a more traditional Alberta Clipper. It will bring some snow to MRG Sunday night setting the stage for a chilly but semi-powdery Monday. The system Sunday night has the look of a 2-4 inch event but this could change in the days ahead

I am certainly more encouraged about the way things may play out next week. Arctic chill will be able to maintain its footing through Tuesday morning before milder temperatures make another northward charge. I had advertised the possibility or record warmth a few days ago. That appears a little less likely now but more importantly the recent run of the European model showed the overall mild pattern more or less collapsing on itself late next week under the weight of what could prove to be an intriguing weather feature. I do feel fairly confident overall that ultimately, we will see some critical loosening of the Pacific Jet and a reversal of the PNA by Super Bowl weekend. How fast these changes manifest themselves into some tangible powdery goodness remains a question. There are hints that things could get very interesting along the east coast in the period between the 2nd and 5th of Feb. We have yet to see any real consistency but whispers of an east coast "bomb" began and I hope we can turn this into some real talk.

At the very least however, we should be able to look forward to an exciting 7-10 day stretch of weather beginning around the time of February 3. The PNA will be very supportive and will be coupled with at least some weak high latitude blocking either over Greenland or over the Arctic regions.

Tuesday, January 24, 2012

Close call Friday but not looking good, weekend still looks wintry

We are in the midst of a very lousy upper air jet stream pattern. We paid for it Monday with mild temperatures and rain. We will likely pay for it again next week. Friday however remains a close call and the upcoming weekend will mark an interruption from the prevailing theme of the week. Models have had a very difficult time with Friday's system and the forecast has remained in an invariable state of flux for a few days. It looks as of now as if we will get an organized weather system fueled by Gulf moisture arriving Thursday night. There is almost no available cold air in the vicinity thanks to a dominant upper ridge positioned across eastern Canada. There is a little support coming from a polar-pacific impulse. It will dive underneath the Canadian ridge and attempt to inject a little bit of chill along with guiding the storm south of the St Lawrence Valley. It may not be enough in the end but its a close call. Precipitation will begin in the pre-dawn hours Friday and persist through a good part of the day. My guess right now is for an event consisting of sleet, freezing rain and some rain but it is close and a small change could improve the forecast. Areas north of Smuggs stand a better chance of getting some snow out of this system.

The weekend does mark a break from the madness of the mild air. We should get albeit temporary but significant east coast trough amplification. The result will be more seasonable and even below normal temperatures but it should also mean snow showers later in the day Saturday into Saturday night. The best chance for a powder day would be Sunday. I woudn't expect epic snow but a few inches is certainly possible.

The cold weather will persist through Monday but we will again see the reemergence of a dominant upper ridge that spans all of eastern North America. The coupling of Pacific energy and trough over Alaska and the ridging in the mid-latitude Pacific is just killing us. It is causing Pacific air to run the country over and in this case it will trigger record warmth across parts of the east coast and quite possible interior New England by the middle of next week.

Fortunately the winter thaw does appear to have an end on the horizon. By about the time of Super Bowl weekend there is evidence of a loosening of the Jet in the Pacific and a re-positioning of the ridge over North America farther west. This will allow the PNA index to go from highly unfavorable to favorable while the North Atlantic oscillation remains slightly favorable with slight evidence of blocking over Greenland. I know it hurts but keep the faith, we still have time to save the Presidents day holiday and beyond.

Speaking of the Super Bowl, we have a Giants vs Pats rematch which I am sure many loyal MRG skiers against one another. It was a game for the ages last time and I fully expect another one this go around. What I will never forget about 2008 however was the incredible rally we got in the weather in the week that followed Super Bowl 42. It looked for all the world that we would get 2 days of rain 40 degree temperatures. Suddenly, the Giants upset the Pats and just as dramatically the weather forecast shifted. Arctic air fought its way into interior New England and a train of low pressure systems delivered MRG like 30 inches of powder in 3 days.

Yeah its a reach but I am feeling around for some karma !!

Sunday, January 22, 2012

Mild upcoming week perhaps not as bad as initially thought

The upcoming week had trouble written all over it going back two weeks. The forecast has in fact improved in recent days and we still could save the weekend of the 28th and 29th if we are lucky. First we are going to have to endure some freezing rain/drizzle Monday morning which will ultimately give way to rain and 40-degree temperatures Monday evening and Monday night. Following that the mountain will see a few dry and unseasonably warm days with temperatures in the 30's by day and 20's during the overnight. It is a very unexciting short term outlook but recall that I had expected worse with temperatures reaching 50 for one day and 40's for three.

By later Thursday it will again get interesting or perhaps it won't. The furious jet energy battering the Pacific Northwest will have won the U.S. over for the most part with mild weather spanning the area east of the front-range. On Wednesday, a storm will begin to gathering strength along the Texas coast and move northeast. It is likely to bring precipitation to MRG by late Thursday or early Friday. A few days ago I would have told you decisively that this would be a rain event and it still could be due to a lack of available cold. Split flow in the jet stream however provides a bit more drama to this storyline and some northern branch jet energy will try and undercut the large eastern Canadian ridge just as the more organized storm system approaches from the southwest. Both the American, European and Canadian models have had different things to say about this at different times. The recent run of the American model which is being released as I write this suggests the southern plains low pressure area late this week will get left back until the next system picks it up over the weekend turning it into a potential snow producer Saturday night into Sunday.

Given the period in question is less than a week away, the models are unusually disoriented and the specifics of the forecast picture will remain clouded for another day or two. With better certainty though I can say temperatures appear more winter-like for the weekend and that at a minimum, terrain induced snow showers should add at least a light accumulation of snow to the mountain.

Beyond the weekend moves us toward February and crunch time at MRG. Indications are inconclusive for the weekend and are even more inconclusive next week and beyond. Teleconnection indices appear move favorable overall with support coming from a slightly negative AO and NAO. The PNA is also expected to relax allowing the Pacific Northwest a break from the onslaught of storminess. The two dominant players on our side of the hemisphere will be a ridge setting up between the Aleutian Islands and the Gulf of Alaska and a downstream trough setting up between the Rockies and the Plains. The problem here is that the aforementioned sentence offers way too broad of a range of possibilities by the first of February. In short, we can derive optimism from both the GFS and European ensembles as we move into February but the GFS shows a more abrupt and quicker weakening of the Pacific Jet allowing these positive changes to occur more quickly. The European Ensembles suggest another push of mild weather toward the end of Jan or early in Feb before it gets better by the first full weekend of Feb.

Joe Paterno you are still loved by students and alumni that watched you coach. It is very sad to you go out the way you did. No one is life is perfect and everyone and anyone can be guilty of lapses in judgement but your positive impact on the people around you far out-weighed the negative.

Thursday, January 19, 2012

Light snow Saturday, freezing rain to rain on Monday

The fast moving storm system slated to move from the Rockies Friday to the east coast Saturday will spread snow into Vermont Saturday morning. For the northern third of Vermont, it will be very close. The best snow from this storm appears to be across southern New England where 4-6 inches is expected. Farther north it will be difficult for some of this moisture to penetrate a very dry and very cold airmass. It is still reasonable to expect some light snow to begin early in the day and continue through early in the afternoon but accumulations will be on the lighter, 1-3 inch side. Still with the fresh snow from Thursday night into Friday morning it should be a pretty good day to ski. Sunday's temps will start below zero but moderate significantly by the afternoon rising into the 20's.

Temps will continue the moderation into Monday when a more potent storm system approaches and tracks directly north out of the southern plains to the eastern Great Lakes. The region will thus get flooded with warm air, initially just at the tropospheric mid-levels and ultimately everywhere. A period of freezing rain or drizzle is likely during the day Monday. By Monday night, the front associated with this storm system will arrive flushing out any lingering cold and bringing a period of rain along with a night of 40-plus temperatures.

Monday's system is a no-doubt-about-it loser and the airmass in the wake of Monday's system will be represented by relatively benign Pacific air. Such airmasses might feel nice but they are a direct product of that angry Pacific Jet out west. Much of the east including even Vermont will struggle to see temperatures well below freezing. The pattern will be conducive for another rain event later in the week but models have been a bit more capricious in this time frame. Some even engaging in a little bit of hope for MRG.

More on the long range this weekend after a few good nights of sleep. Stay warm this weekend and enjoy whatever snow we get.

Tuesday, January 17, 2012

Snow from two different systems should turn this weekend into a winner

It still looks we have two potential snow producers on the weather map both of which should help turn the upcoming weekend into our 2nd consecutive winner. Both are products of a furious Pacific Jet Stream which is expected to grow even stronger over the next week. The first, as mentioned in the previous update carries little moisture but has plenty of cold to work with. It will spread clouds to the region Thursday afternoon and light but very fluffy snow Thursday night (the cold weather and lack of Atlantic moisture will help keep the density of this snow very light). Friday will therefore be a chilly powder day with 2-4 of new snow at first tracks time. Following a very chilly Saturday night with well below zero temperatures, milder air will begin its big push north. Cold air across interior New England, rarely gives up without a fight and the weekend should be no exception. Yes, the cold weather will gradually give ground but battleground will consist of an overrunning surface capable of producing a healthy period of light to moderate snow over the weekend, likely Saturday. There is a weather system responsible for all this and it will track from the central Rockies to the Atlantic coast very quickly Friday and Saturday. Where the moist conveyor sets up with this system remains a question so the range of possibilities for Saturday spans from a dusting to as much as 8 inches, but I expect something in the middle.

And then the pain begins. We will survive Sunday with below freezing temperatures and perhaps some lingering snow. I know the Pats and Giants are both playing huge games Sunday but winter might be taking an extended break after Sunday so it might be worth grabbing a piece if you can (For me the Giants will be tough to miss). It has been the Euro and its ensemble package which has been driving the train of a end-of-the-month January thaw. It all stems from the strong coupling of a trough across the Pacific Northwest and Canadian Rockies and a ridge across the desert Southwest. The result will be the formation of a very, very large ridge across centered over much of eastern Canada. How warm will it get and for how long ? I would expect a 3 day stretch of 40-plus maximum temperatures and 1 day with 50-plus temperatures. And I would also expect a rain event either in the middle or end of the week. Recent runs of the American GFS model do offer us an out next week by pushing the ridge far enough to the northeast so the warming is substantially mitigated. The history of this winter so far and the superiority of the European model in the last few months makes my educated guess an easy one to make but time will tell. Hopefully I get proven very wrong !

Things look a bit more encouraging toward the 1st of February when both the European and GFS Ensemble packages allow the ridging in eastern Canada to evolve into what could become a Greenland Block. This would turn the NAO negative and give us an ally in the fight against what has been a fierce Jet in the Pacific.

Sunday, January 15, 2012

Wintry upcoming week but the end of the month looks distressing

Snow on the ground and sub-zero temps has finally put Vermont in the spirit of the season and we should continue with this theme through the upcoming week. A brutally cold arctic air mass has begun its descent into western and central Canada and will ultimately grip much of the northern third of the U.S. this week. The southward push of cold however will not occur without a fight and this sets the stage for a sharp temperature gradient that will set up between the 35th and 40th parallel (that's old school for latitude). This temperature gradient will help carve the pathway for what appears to be two pieces of Pacific energy capable of delivering powder to MRG.

The first weather system marks the advance of the large southward advance of aforementioned arctic air and it will arrive later Tuesday. Of course, we already have very cold air gripping the region and it will gradually loosen its hard grip ahead of the arrival of Tuesday's system. By midday Tuesday, temperatures will warm to within a few degrees of the freezing mark and it will be the thickening clouds that slows the warming. Precipitation will then start as a wintry mix before going to all snow Tuesday night into early Wednesday. The low pressure center responsible will track directly over northern Vermont thus placing the best snow accumulations over Quebec. MRG should in the end do OK with a few inches to show for itself by Wednesday when blustery and very cold weather should reemerge across the region.

A second system late Thursday into Friday will have plenty of cold air to work with but will be a bit moisture starved. We should be able to squeeze a few inches of fluff out of this before cold air is re-enforced for the last time before an uninvited pattern change begins to take root. Thankfully these changes will not have an adverse impact on the weekend of the 21st and 22nd which I would expect should still be a winner. Very cold air will still be in place on Friday along with a few inches of fresh snow and the northward push of milder air will be fueled by a weather system capable of delivering additional and potentially significant snows to interior New England Saturday. I will wait for the next update to provide a bit more clarity on that.

Beyond next weekend is when the big trouble begins. The big personality characteristic so far this winter has been a very tight and very powerful jet stream in the mid-latitude Pacific. Unfortunately we will see this reemerge again and in a very bad way as much of the energy will be focused on the Pacific Northwest and Canadian Rockies. This will allow for a strong upper ridge to develop across southeastern Canada and New England. It is the kind of feature that can produce both record warmth and rain both of which are probable between the 23rd and 27th of the month. With these changes still a week away there are still a few outs but its not worth holding our breath right now.

Thursday, January 12, 2012

A few tweaks and a few more specifics but expectations haven't changed

The first area of precipitation brought 4-6 inches of snow, sleet and freezing drizzle to the northern Green Mountains. As expected, the evening and overnight hours should be relatively quiet although sporadic freezing drizzle could cause trouble on some of the roads. The second low pressure center is spinning its wheels across the Midwest and beginning to push east. It is a very dynamic system with some vigorous jet stream support as alluded to in previous posts. Temperatures in the lowest few thousand feet of the atmosphere, based on some cross sectional analysis will be a bit marginal during the early morning Friday so when precipitation re-commences in earnest between 5 and 7 am it might be more of a sleety rain. By 9 AM the lower troposphere will have destabilized significantly and we should see rain change to snow and temperatures to turn abruptly colder. Snow should continue through much of the day and could at times become heavy during the evening Friday. 6-12 inches of powder Friday and Friday night is a conservative estimate. I would not at all be surprised if we outperform. A lot of the NWS forecasts will be tailored to valley locations where accumulations will be substantially less. Right now for instance the NWS forecast for Washington County says 1-3 Friday with an 80 percent chance of snow Friday night.

Snow showers should continue into Saturday but it will be cold and windy. Wind should taper off somewhat Sunday and completely by Monday although temperatures will be wintry dropping well below zero overnight and only rising into the teens during the day.

There are a couple of more chances for snow both late in the week and next weekend before we may have to battle more adversity by the 23rd or so of the month. More on that in a subsequent update but for now go find some of that long awaited untracked powder !!

Tuesday, January 10, 2012

10 - 20 inches of snow & some sleet for Thursday/Friday

January 10th on the calendar marks the first occasion the blog can get excited about an event. Not exactly the kind of winter I had hoped for as of yet but at least we DO have a storm that can deliver for us in time for MLK holiday. This winter storm is coming together as of the time of this update with moisture advancing up through the Ohio Valley and jet energy ready to plunge into the thick of things by Thursday. The initial thrust of "moisture" with this system will remain ahead of some of this jet energy but we talked about the importance of attaining some "over-the-top" cold from Quebec and we will get such assistance even if its just a little.

By the time precipitation starts early Thursday temperatures will be well below freezing and by the looks of things it will be snow. The snow could quickly become very heavy Thursday morning as some of the best upward motion should occur in the late morning hours. As this is occurring however we should see an above-freezing layer advance into the region above the surface, changing precipitation to a period of sleet. by later in the day we will likely see a "lull" in the precipitation as temperatures make a slow advance to 30. 4-8 inches of snow and sleet would be my guess for Thursday only. Best chance of skiing in powder will be the morning before the sleet begins in the afternoon.

It is likely to get really fun as we move toward Friday. The lower troposphere will cool in the Thursday night/Friday morning time frame and models are keying on a very interesting jet max as this is occurring. This feature will allow an area of precipitation to enhance across Pennsylvania and New York before moving into Vermont in the pre-dawn hours Friday. All of this should be snow by the time it reaches MRG and although it could be a little wet at first Friday morning, temperatures will trend colder throughout the day, and the powder should start to pile up. It should persist through much of the day with the heaviest in the morning. Snow showers and flurries however will continue into Friday night and into Saturday morning. The additional 6-12 inches we should see in this time frame put this storm in the 10-20 inch category. It is not impossible for us to do even better, a lot depends on how Friday evolves.

The rest of MLK weekend appears mainly dry. The one clipper on the weather map Sunday will pass well to our south. Temperatures will be chilly with teens expected Saturday along with well-below zero wind chills (nothing we can't handle), and sub zero temps Sunday in the morning and teens in the afternoon although less wind. MLK day should be similar to Sunday with even less wind.

The balance of next week continues to appear mainly cold with the exception of late Tuesday into early Wednesday. Milder temperatures will attempt to make a push into the region in this time frame and I am hoping this ends up being an excuse for us to pick up some overrunning snows. The end of the week should feature some of the coldest weather of the season so far with temperatures falling into the -10 F category. Again nothing we can't handle and this cold will abate by next weekend when I am hoping some light snow from a clipper system can provide some additional fresh powder.

I am not in any sort of mood to focus on the weather beyond this. Ensembles are showing the PNA winning out with the cold and snow focused on western North America and lower Alaska. I am giddy about the upcoming storm and will simply hope things start to look a bit different late in the month before I have to provide another update. For now lets just enjoy some winter, we have waited long enough for it.

Sunday, January 8, 2012

First extended period of "Winter" comes after Thursday/Friday event

Aside from a little snowfall Monday night, amounting to an inch or two at best, we will now focus our attention on the Thursday/Friday system. This particular storm has all the makings of a beauty for MRG. Its got moisture from the Gulf and will track right over southeastern New England. As mentioned in the last update however, it has little cold air support. Much of it will have eroded and forecast temperature cross sections will be very marginal when precipitation begins early Thursday. Marginal does not necessarily mean rain, it is actually very close. Temperatures in the lowest 6,000 or so feet of the atmosphere will be within a degree or so of freezing and a shallow layer of below freezing temperatures at the surface may allow for a prolonged period of a sleet/snow/freezing rain mixture. Not ideal skiing weather and certainly not a powder day Thursday but that kind of stuff is good base building material and I would certainly take a few inches of that over rain. As you move north along the spine of the Green Mountains, chances improve for precipitation to be more snow less sleet. Jay Peak, as is the case many times, will likely triumph.

The system traveling through southeastern New England Thursday is the first of two significant pieces of energy capable of delivering the region precipitation. The second is polar jet energy which carries with it less moisture but its arrival will bring both colder temperatures and what appears to be a pool of instability capable of producing a period of some terrain induced snows Friday. At least a few inches are likely ahead of what should be a winter-like weekend with well below freezing temperatures and perhaps more snow showers if we are lucky. All of this comes as the AO makes its awaited switch, the switch that will finally allow winter to make an extended stay into Vermont.

The model guidance has been very inconsistent after the upcoming weekend. The global picture however makes a little more sense. The biggest feature on the weather board is a "blocking" ridge which will extend up from the Bering Sea to the Arctic regions. This should force much of the cold into North America but it is tough to discern where the focus of this cold will be. Ensembles show that some of it travels in to places such as Vermont while a bulk of it will wind up in the Pacific Northwest by the 18th or 19th of the month. With the polar branch of the Jet occupying mid-latitude North American it might be difficult to get Gulf or Atlantic Moisture into many of the passing weather systems. The Jet energy from polar regions often thwarts such attempts but fast moving clipper systems will still bring powder to the region at least twice between the 15th and 19th of the month.

It gets a little tricky after the 19th as much of the Ensemble data points toward colder, more active weather in western North America, a faster and more energetic Pacific Jet Stream and a relaxation of the cold in eastern North America. The AO will remain negative but will be forced to compete with the PNA to win over Vermont and the rest of interior New England.

Thursday, January 5, 2012

Could be another rough upcoming week but light at the end of the tunnel still looks bright

My Alma Mater, Penn State, university has endured a rough couple months but they just took a big risk by hiring Pats OC Bill O'Brien to be the next HC. I have no idea who this guy is except that he shouted at Tom Brady a few weeks ago (which i find rather impressive actually). Much of Penn State nation is in total meltdown mode by the way and ready to jump off a cliff (much bigger than the one in "the garden" btw). Any Pats fans have opinions about this guy ? I would love to hear it, email or otherwise.

Anyway, the possibility for a significant snows early next week has fallen to pieces. Unless things change dramatically, the jet impulse that could have been the catalyst Sunday will be a dud and incapable of manufacturing an east coast storm as we had hoped. Much of the jet energy early next week will get initially trapped over Texas giving the jet stream an "L Shape" configuration across eastern North America. We could handle this but there isn't a lot of southern branch jet energy this year with the prevailing La Nina to move this system along. It will gather moisture over the Gulf as the limited cold air across the Northeast erodes. By the middle of the week it will begin its northeastward progress as potent polar jet energy picks it up.

This is a big precipitation producer undoubtedly and Mad River Glen is going a substantial chunk of it late in the week. There are a couple of different ways this could evolve but it appears for now that we will not have the cold air in place for precipitation to start as snow and more likely rain. Depending on the track of the storm, the way in which it transitions to an east coast low pressure area, and particularly how the incoming cold weather becomes enveloped in this storm will determine our eventual fate. Most indications indicate that that the cold weather will arrive on the back side of the developed storm giving us a chance for wrap-around and terrain induced snows by next weekend. We would do better however if some of this cold could work its way in via the Quebec route and involve itself a bit with the moist conveyor of this storm.

The AO is still on target to make the critical switch around January 12th which will allow the cold weather to be more sustainable and significant snow to be much more likely. Still doesn't look like a home run pattern but the best we have seen so far this winter season.

Tuesday, January 3, 2012

It's getting more and more interesting !!

With two successive runs of the European Model advertising the development of an east coast low pressure center over southern New England Sunday the 8th. The last run of the Euro showed the storm "bombing" near Boston Harbor and yielding foot-plus snows for much of the Green Mountain spine. The American model is not on board with the Sunday-Monday event but the Canadian model does show some indications of a storm albeit a smaller storm. The differences in the model are easy to decipher. The European simply shows a more potent upper level impulse capable of assuming the "protagonist" role. The American model no protagonist but merely a cold front innocently doing away with the mild weather we are expecting this Saturday.

A potentially stronger weather event or precipitation producer is more than possible for late in the week. This is, as promised, the beginning of a much more active and much more interesting period in our winter weather. This weather system will likely approach New England as much of the cold weather has made its exit. It also may travel along a path that could spread rain, at least initially to much of Vermont although this remains somewhat uncertain. There is a strong and very fresh supply of cold that may ultimately get enveloped into this storm and allow for a significant period of snow before temperatures return to typical January levels for the middle of the month.

The best news however involves the long long long awaited Arctic Oscillation sign switch. Yes, this is the decisive turn that has eluded us. This turn in the AO will put the breeze at our backs by the middle of the month and although we will still need to contend with a negative PNA with much of the jet energy in the west, the AO is the big enchilada and by January 12th or 13th it will be on our side of the pitch.

Monday, January 2, 2012

The holidays are over and we need to gear up for crunch time

I hope everyone had a good and safe holiday and have a good 2012. Hopefully the weather will begin to cooperate for us powder enthusiasts, that is my wish for 2012. We have completed another bout with mild weather and will get a nice blast of winter with some sub-zero temperatures and very sub-zero wind chills between Tuesday and Wednesday mornings. We will get some flurries and snow showers as well but we will not have the right combination of low level instability and moisture to produce a big terrain-induced snow event. The east coast trough responsible for the first widespread outbreak of cold will get re-enforced very briefly Thursday and with this will come some clipper snows of perhaps a few inches. Temperatures will then moderate but this mild push of weather will only give us a glancing blow.

A quick word about the rapidly evolving weather pattern. It looks initially like a sequel to the December 2011 movie but will gradually evolve a bit differently. The upper ridge in the central Pacific will become more dominant and begin to displace the polar vortex over Alaska. These are not exactly the needed ingredients for a decisive change of momentum but it is a different pattern verses December and should yield some better results. We will have to overcome a pattern that focuses much of the snow and cold on the central and northern Rocky Mountains. It will, beginning next week, be a much better period for our western powder lovers. Can we overcome a pattern dominated by much of the jet stream energy focused on the west ? Perhaps. If so, the assist will come from changes over the Atlantic where an upper ridge is expected to form south of Greenland. It is physically impossible to have a ridge located there and have another over New England. The European ensembles agree and are suggesting and interesting and more active set-up next week and beyond that includes mild weather over the southeast battling it out with colder weather trying to make a southward push from Canada. We could continue to lose these battles, as we did in December and struggle. But we need these types of battles to have any chance for big snow and I like our chances a bit better with this set-up, a more traditional La Nina long-wave pattern.

The milder weather next weekend will have the biggest impact on locations farther south. Interior New England will have a couple of above-freezing afternoons before a colder push early next week pushes temperatures back to more seasonable levels. From there, let the games begin. Between the 9th and 20th of the month, I would expect at least 3 chances for significant snows. Sleet and ice are also possible in any of these events but a good sleet event is great base building material and I would take some of that as well.