Think Snow, Tweet Snow !!!

Thursday, January 31, 2013

New snow is on the way, just a question of when and how much

Temperatures fell quickly Thursday back to sub-freezing levels after an incredibly damaging thaw featuring an "all of the above" plethora of snow eating variables including warmth, high dewpoints, wind and rain. We will need a lot of help to recover but help is coming in immediate fashion. Low level instability combined with Great Lakes moisture will work to induce the terrain enhanced snow showers that we are typically so dependent on. The period between between Thursday evening and midday Friday should feature on and off snow showers and squalls, enough to produce 3-5 inches of powder before it dries out Friday afternoon. This is much needed first aid but the mountain will obviously need a bit more before returning to top form.

There is plenty weather worthy of discussion over the next week or so and I am happy to report that none of this talk will concern rain. Temperatures will be on the colder side of average with most of these days below 20 on the mountain and a few nights below zero. A series of clipper disturbances rotating through the polar jet will impact New England and there are important questions relating to where and how much it will snow. The first will dive into the Midwest Saturday as a disjointed and disorganized system. There essentially is two weak upper air impulses with the second catching the first on Sunday, giving it a much needed boost as it interacts with the Atlantic Coast. The result could be either good or bad. If the system can strengthen quickly and efficiently it could effectively suck moisture back over interior New England. If the system is slow to strengthen as it encounters the coastline, it could act to simply consolidate its energy off shore as a couple of recent clippers have done this month. I am worried about the latter and some of the recent computer guidance is indicating such an outcome but even in this case, limited amounts of moisture should be enough to produce a light 1-3 inch snowfall Sunday, hopefully its more. One or perhaps even two additional clipper systems will track across the Midwest early next week. Models have shifted the track of this system or systems southward in the last 24 hours. That being said, the situation has been very fluid and small changes in timing or interactions make the outcomes look different every time new model data is released. 24-hours ago, there were stronger indications that one of these systems would blow up off the coast and become a significant snow producer and I would not declare that possibility dead yet.

The cold weather will persist in to the later stages of next week and then the arctic air will begin a retreat into central and northern Canada. Milder Pacific air will thus be allowed to dominate much of the country by the 10th or so of the month. In spite of all this, and the inevitable mention of the "evil empire", there is a silver lining in the forecast. The cold will not give ground quickly and a more significant weather system will likely move out of the Rocky Mountains late next week and is likely going to be one of the first more organized snow producers to have a more direct impact on the region in too long. So even as the more intense cold is retreating, the weekend of the 9th and 10th could be one of the better weekends since early January. Thereafter, the evil empire will become a more dominant player but maybe not too dominant. Ensembles indicate a strengthening of a ridge in the Pacific coupled with a trough over Alaska. This combination floods the country with Pacific air as mentioned and temperatures on the mountain will certainly warm by the 11th of the month. It is possible however that the evil empire has a short reign of terror this go round as the signal is expected to quickly weaken within a few days. It has been a noticeable characteristic of the winter season 2012-13. Warm or cold patterns have generally failed to gain a lasting foothold on the region and we have watched weather conditions swing violently in both directions since early December.


Wednesday, January 30, 2013

Damaging thaw will be followed by much colder weather and snow

Wednesday's thaw is a nasty one. Dewpoints in the 40's, strong south winds and not to be forgotten, the rain. It will be a heavy soaking rain as well which should begin Wednesday evening and persist through a good chunk of the overnight. Rainfall could total over an inch and rumbles of thunder might be heard throughout the Green Mountains. Thaws are a fact of life in any New England winter, even the colder winters, but this surge of warmth will be particularly crippling to ski areas across the region because of the intensity. The rain will be over and done with Thursday evening and colder temperatures will quickly displace the warmth and bring temperatures back to below freezing levels Thursday night. 

Our snowpack will be on life support by Thursday and our need for fresh snow will be as great as ever. Fortunately there are a few chances during the first 7 days of February. A weak disturbance should allow for some terrain induced snow Friday but two potent Canadian clippers have the potential to be snow producers, both getting a late injection of Atlantic moisture. The first brings its chance for snow Sunday. It will appear like a disorganized system as it travels through the Midwest but then organize along the Atlantic Coast and potentially spread moisture back into interior sections of New England in the form of snow. The second is a more potent weather system and even more capable of bringing significant snow to New England on Monday ot Tuesday. The question relates to where and that will depend on the eventual tracks of both systems. The roller coaster temperature ride will also continue I almost forgot to mention. Temperatures will again drop well below normal by Friday and generally remain there through a good part of next week. This means plenty of days with temps in the teens by day and well below zero at night.

The longer range outlook has taken an unfortunate turn for the worse and it fits the back and forth personality of the winter. It's the evil empire yet again. All three major ensemble packages show its return. The more energetic Pacific Jet Stream  will force more Pacific air into the U.S. after February 7th allowing for temperatures to moderate. In spite of all this, there are indications of a big winter weather producer for the 2nd weekend of February.

Sunday, January 27, 2013

$3.50 to ski in 4-8 inches. Get it while it lasts !!

A decent snow is on the top of our wish list and believe it or not it's coming. I am honestly surprised that the National Weather Service seems to content with no watches or advisories and is suggesting 1-3 inches Monday night. The swath of moisture associated with the initial push of milder temperatures is quite impressive and although it will encounter some very dry air as it moves east, it will nonetheless maintain good frontogenetic support. Snow should begin in the evening Monday and occasionally fall at a moderate or evening heavy clip during the late evening and overnight hours. Temperatures will rise into the low 20's Monday and remain there through Monday night which will seem almost tropical around here compared to the last 5 days but still cold enough to support powder. By Tuesday morning we should have a good 4-8 inches of powder and about a day to enjoy it before it turns very warm and very wet at MRG. 1949 prices seems like a pretty good bargain for what should be a cloudy and calm day with temperatures just below freezing. Some freezing drizzle Tuesday is about the only daytime precipitation we should see.

The thaw Wednesdsay is the classic New England skiers nightmare. It comes fast and furious with wind and high dewpoints, two very destructive components. We could see the occasional freezing drizzle Tuesday turn to a steadier freezing rain Tuesday night. By late on Wedneday temperatures will surge into the 50's at the base, aided by some sunshine and the aforementioned winds. The rain will arrive Wednesday evening and could also become heavy during the night. In summary, the thaw will again be quite destructive and put our limited base on the defensive while destroying the snowpack in valley locations.

The intensity of the upcoming thaw certainly has taken me by surprise but the weather has been very changeable this season and has included some violent temperature fluctuations. We will see this continue late this week with plummeting temperatures again thanks to another arctic surge of air. Lingering instability in the wake of the passage of the cold front will allow for snow showers late this week but accumulations will be minimal. The next chance for significant snow comes over the weekend from what looks to be a fairly potent clipper system. This system has some potential to produce a light to moderate snowfall but remains 5-6 days away so we should expect some forecast adjustments.

We successfully align the 3 major teleconnection indices for a period of about 5 days beginning on the last day of January and ending February 5. In this period temperatures will remain cold and snowfall will come mainly from clippers or weaker disturbances. Beyond February 5th there are now clearer indications both good and bad. The good involves the activity in the pattern with at least one major weather system indicated in the first full week of February. The bad involves the ridge/trough axis which is indicated to shift west and this put interior New England in a clash zone between mild and very cold air. This can lead to a very good result but we would prefer to see no risk of any more mild intrusions for a while.

Thursday, January 24, 2013

Swing and a miss this weekend, some snow next week but a brief thaw in the middle

This will be another abbreviated update since a tablespoon of coffee just put my labtop on injured reserve for a time. Mentally I am also on injured reserve since our late week storm is wide right. It might still be the 9th inning but there are two outs and two strikes and it looks for all the world that this storm will get shunted out to sea as it consolidates its energy off the coast. Some snow starved areas in the Mid-Atlantic should get a long awaited taste of snow but they don't appreciate the powder like we do and I mean no offense toward them. In the meantime, the extreme cold gripping the Mad River Valley will gravitate back toward more garden variety cold by the end of the weekend. We could get a brief period of light snow Friday night but for the most part, the upcoming three days should feature lots of sunshine.  Saturday will be a bit on the breezy side but both Friday and Sunday can be characterized as calm and cold.

Our next shot of snow comes as a result of a mild push of air. It will take some work to get the mild air into interior New England and although that battle will be lost for a day next week we should see some snow Monday night into Tuesday thanks to this warm front. The mild day, and it looks likes we see one, occurs Wednesday. I am hoping that blocking at the extreme high latitudes finds away out of this but in any case, the mild surge will be a brief one resulting in a day of above freezing temps. Rain and damaging wind is also possible but hopefully any of that will be very brief.

In spite of our miss on the storm and a potential brief thaw next week, you have to like the fundamentals anchoring this pattern going forward. The evil empire will go into hibernation for a time (although it rears its head briefly next week) and lets not wake this sleeping troll. Furthermore, we should see continued support from all of the teleconnection indices especially during the first 7-10 days of February. The missing ingredient is the big storm and we need to jump start the southern branch of the jet stream to help improve our chances. Although there remains hints of split flow and some activity in the pattern there remain only vague signals. I would venture to guess that weaker disturbances will deposit some fresh snow prior to the first full weekend of February with a slight chance of a bigger storm around the time of this weekend. Stay warm this weekend and don't spill any coffee on any laptops if your not on the slopes.

Wednesday, January 23, 2013

Friday/Saturday storm still possible but latest info takes it mostly out into the ocean

The Friday/Saturday weather system still has promise. It has all the ingredients to become a major snow producer for New England but the components of this mixture may not be in the right place at the right time. In a nutshell, there is a critical shortwave in the polar branch of jet stream that will need to dig a little deeper Friday and help ignite this storm before it slumps into the Atlantic Ocean. There is no reason to think this isn't possible but recent model guidance says that this much needed storm is a no go with snow confined to southeast New England. We have seen this movie before, we have seen 11th hour, 9th inning twists of fate and we may need one here. I'll have a fuller update by Thursday morning but in the near term, we need to root this storm along.

Sunday, January 20, 2013

Very cold upcoming week will hopefully conclude with some significant snow

Temperatures are falling across Vermont and in the coming days, the mountain, the state and the entire region will be in the deep freeze. It is as impressive of an outbreak of cold as the region has seen in the last half a decade, perhaps even dating back to 2004 which was the last January outbreak of cold that challenged records across New England. The stronger outbreaks of cold in New England and particularly in Vermont occur when cold is delivered straight out of Canada as opposed to the Great Lakes region directly to the west. This initial blast of chill Sunday night into Monday has been modified somewhat by the open waters of the Great Lakes. A clipper system, the last of a 3-part series will ultimately bring unmodified arctic air of a very intense variety. We are of course most interested in the clipper for its snow. It will have a very limited amount of moisture as it tracks through the Great Lakes on MLK day but it will get juiced a bit by the warmer Atlantic Ocean. Precipitation will be in the form of snow obviously but most of it will be across coastal New England while a very fluffy 1-3 inches falls across the high terrain of central and northern Vermont. The snow from this system will fall Monday night into Tuesday. Temperatures will be in the 0-10 degree range through Tuesday but will plummet further Tuesday night, perhaps all the way to -20 by Wednesday morning. It may then be all the way until Thursday afternoon before temperatures get above zero again.

The elephant in the room, as it is most of the time, involves snow. The sooner we get a big snow the sooner the Single Chair begins spinning and the main mountain opens. As of January 20th, new snow has been quite sparse this month and the need is great in the wake of last weekends thaw. Our big chance, what I hope will be the first of many, comes Friday. This is a system that will come out of the Rockies early Thursday and proceed quickly through the Great Lakes. It will move quickly and will thus have a limited time to gather both moisture and any serious strength along the Atlantic coast. Nonetheless, the system has the ingredients to produce snow, mainly as a result of what should be a broad overrunning surface. Everything with this system will hinge on the track. The polar jet will need to ease its grip just enough to allow this system to track toward Cape Cod. It's not asking a lot and two of the three major computer simulations are currently suggesting a healthy dose of snow on Friday following the two day period of extreme cold. The American GFS model has at times suggested this system remaining to the region's south, keeping the mountain dry and cold.

Still looking at a very fluid situation for the last 6 days of the month. Friday's potential storm is followed by another push of arctic cold, though not quite as strong as what we expect Wednesday and Thursday of this week. Ensembles are keying in on a warm-up and a potential brief thaw around the 29th or 30th of the month only to be quickly followed by another period of colder weather by the beginning of February. Through all this, we should continue to see at least some support from NAO and AO and we have to hope that the blocking can help mitigate the effects of any mild push of air. It is not an unreasonable expectation. Milder pushes can appear dangerous but can also prove to be a mechanism for new snow.

Friday, January 18, 2013

Light amounts of new snow through the weekend and a more oganized snow produder possible late next week

At least a few inches of snow is covering the thick layer of crust across the Green Mountains. It will take several days, but we should be able to add a few more inches and set ourselves up for another extended period of good skiing, I hope. In the short term, we will have to settle for the proverbial "bunt single" or two. The arctic air has arrived and disturbances rotating through the polar jet will bring the limited snow through the weekend. The snow should begin again Friday night, taper to flurries Saturday and evolve into snow showers or even a brief burst of heavier snow Sunday as another and stronger shot of arctic chill advances on the region. I can't guess if its enough to get the main mountain back in business but the few inches Friday night and few inches Saturday should total 4-8 inches over that 3-day period. The third clipper feature discussed in the last update does not appear as promising according to the last 3 or so cycle of model runs but it still has the potential to quickly strengthen off the Atlantic coast. Because of its quick movement however, the chances of it having any meaningful impact on Vermont have decreased considerably.

Most of the snow shower activity after Monday will be focused on areas farther south and although some Lake Champlain induced flurries remains possible in the Monday-Thursday period, the main story will be extreme cold. Temperatures throughout this period will struggle to get past 10 across the mountains and fall well below zero at night. This particular outbreak of cold should best anything we saw last year in both intensity and duration. Previous runs of the American Model and a few runs of the Canadian model showed a clipper system in the middle of next week capable of producing snow but the main thrust of the Jet Stream will be pretty far south during this time I would venture to guess that any clipper system would prefer a southern route.

We have seen a convergence of indicators in the last 24-36 hours point to a more organized storm system late next week. The storm would move out of the northern Rockies as the polar jet temporarily recedes northward. With arctic air firmly in place, the groundwork has so-to-speak been laid for a healthy overrunning surface, so as the system moves across the country and attempts to push milder air northward, an expanding shield of precipitation should be the result and some of it will be snow across Vermont. Yes, there have hints that the air could get too mild changing precipitation to sleet or freezing rain but I am not concerned about that yet. The NAO/AO tag team should be put to good use here and prevent the storm from tracking too far up the St Lawrence Valley.

The last 5-days of January appear to be a pretty fluid period across New England. A re-enforcing shot of chill follow the weather system late next week, but this will quickly be followed by another potentially stronger push of mild air associated with another weather system. Snow could be the result but there is a risk around the 28th, 29th or 30th of the month of around a 1-day thaw or precipitation other than snow. At least right now, I like what I see going into early February.

Wednesday, January 16, 2013

Cold and snow to advance on the Vermont high country

The road to recovery begins a little sooner thanks to a wave of low pressure that will bring a swath of precipitation to New England. Mad River Glen is on the northern edge of this shield of moisture but the northern edge is the place to be for snow. It won't be a huge amount, but 3-6 inches is a welcome sight after the damaging and destructive weekend thaw.

Break out the welcome mat for the polar jet after Wednesday's snow. With it will come the arctic cold along with flurries and snow showers Thursday. The PJ will be pretty ferocious but its southward advance will stop over New England and the arctic cold will temporarily be confined to northern New England through the weekend. This also means that precipitation through the weekend will come from disturbances rotating through this powerful jet which at most will take the form of a potent clipper system. A series of three disturbances between late on Friday through early next week should all bring the chance for flurries or snow showers. Each successive feature should be stronger in nature and more capable of bringing fresh snow to the mountain. All three of these relatively moisture hungry systems mark the boundary between cold air to the north and west and warm mild air to the south and east. Light snow Friday evening into Friday night from the first of these disturbances could bring 1 to as much as 4 inches to the mountain by Saturday with the 4 occurring near the summits. Sunday's system appears a bit more dynamic and will have a better pool of instability in its wake possibly yielding 3-7 inches during the day. The last of these three features has the best chance of interacting with the Atlantic Coast. Such an interaction doesn't necessarily mean Vermont gets big snow but the potential does exist for a modest accumulation Monday night into Tuesday.

The cold weather will also play a big role in this upcoming story. This will ultimately become one of the more impressive outbreaks of cold in two years certainly besting anything we saw in last years pathetic excuse of a winter. The "teaser" blast of cold Thursday night into Friday will bring temperatures back below zero but the successive and more vigorous disturbances Sunday and Monday night will bring the Polar Jet further south and advance a serious chunk of cold air into large portion of the eastern United States. The New England high country could certainly see a 1-2 day period next week where temperatures struggle to get above zero even during the day and fall to -10 or even -20 at night.

There is more potential for snow late next week, again coming generally from clipper systems or terrain induced fluff. As mentioned in prior postings, the potential for a more organized system gets higher by the last full weekend of January and beyond. I'll discuss this in more detail in a subsequent update.

Sunday, January 13, 2013

From very mild to very cold in the span of a week

It's always darkest before the dawn and Sunday's 40-plus temperatures marks the peak of what should be our bleakest period this month. Honestly though, this stretch of mild weather could have done even more damage. 2-weeks ago I was honestly concerned that the pattern would produce multiple days of 50-degree temperatures and some heavy rain to go along with it. Much of the rain with the approaching cold front will actually occur in the Midwest and across the Canadian provinces of Ontario and Quebec. A minimal period of rain in the pre-dawn hours Monday morning will probably amount to less than a quarter of an inch and falling temperatures should finally end the snow melt. The SCWB, in some previous posts, had teased about wintry precipitation resulting the one or two waves of low pressure that are expected to form along the suppressed stationary boundary in the coming week. This boundary however will be further south however and forecast for the coming days is substantially drier and colder.

The remaining base will obviously have hardened considerably as temperatures fall. The sooner we can get some new snow, the sooner we can forget about the past few days. As was indicated via twitter, we are headed from one extreme to the other as the pattern will go from one that supported mild weather to one that will support very cold weather. The arctic air will come in the form of a teaser blast late this week before the motherload arrives next week. It seems like it has been forever but at least for a short time, the prevailing negative NAO will align itself with a positive PNA or west coast ridge. This will ultimately lead to a widespread cold outbreak for the eastern United States and conditions will be especially cold across New England beginning Friday and persisting at least a week. Within this stretch we will mostly have to depend on clippers or quick moving upper air disturbances rotating through the polar jet. The first such system comes Thursday with the initial teaser blast of cold. We may only get an inch or two out this and perhaps even less if we are unlucky but this should be the first of many chances. Two clippers, one over the weekend and one marking the bigger arctic outbreak early next week both should bring some new snow to the mountain. One of these two clippers could also blow up into something more significant upon interacting with the Atlantic coast.

Big snows come to Vermont once you add the southern branch of the jet stream into the mix. The southern branch gets involved when it undercuts the ridging in the Pacific. We don't expect this to happen over the next 10 days or so but beyond 10 days (beyond January 24th), it does appear more promising. We will continue to have at least weak support from the AO/NAO combination through the rest of the month but we do lose the support of the PNA. This will cause the arctic air to relax its grip on the region but allow for more storminess in the pattern.

Thursday, January 10, 2013

Back half of Jan looks pretty good !!

With that thought, one has to start with that memorable quote from the end of the movie "Trading Places" starring Dan Akroyd and Eddie Murphy. Looking good Billy Ray !!! Feeling Good Louis !!! This dialogue taking place on the beach after they exacted revenge on Mortimer and Randolph Duke while striking it rich trading frozen concentrated Orange Juice futures. I want this for us at MRG but I want our dialogue to be in the powder obviously. The European and Canadian ensembles could have us indulging in a bit of that fantasy. This would all happen after the 15th and after some rain and very warm temperatures.

The gory details of the coming weekend are not worth spending too much time on. The first area of precipitation arrives in the form of rain and in some areas freezing rain Friday evening. Most of this will be over with by Saturday, a day that should be dominated by low clouds, fog and drizzle with temperatures hovering at or just above the freezing mark. Temperatures and dewpoints could then push into the 40's Sunday with a few periods of rain. Models are hinting that some low level colder air could linger into Sunday thanks to winds that might not be as strong as initially assumed. I am hoping for such an outcome since it's all about damage control Sunday and Monday. The lower the dewpoints, the lower the winds, the lower the loss of snow.

Arctic air will move back into Quebec Monday and eventually force its way underneath the large east coast upper air ridge. This sets up that big temperature gradient I was discussing a few days ago. Temperatures in coastal Carolina and Virginia could push into the 70's while arctic air returns readings back to near 30 in northern Vermont. Waves of low pressure along this intense airmass boundary will move northeast but models have had a difficult time determining which of these waves, if any of them, will be of any consequence. Based on the last round of data our next shot of precipitation would be Tuesday and it's much more likely that it will fall in the form of snow or sleet. This would give the cold air another victory in Vermont in what looked to be a tough fight. We could use new snow or sleet next week since the mountain will have hardened quite a bit from the weekend rain and freezing rain.

So the talk this weekend is that of a thaw and the talk next weekend will be cold. A very big about face in less than 7 days. The combination of a building blocking ridge over Greenland and the evil empire (which will actually drift too far east for its own good) will allow another Polar Vortex to make a run at southeast Canada. Some very cold temperatures is the likely result with some snow preceding it Thursday/Friday of the light variety. Readings for the second time this month should plunge into the -10 territory during the overnights and struggle into the single numbers by day although there is still time for a few variations in this forecast.

The back half of January forecast hinges on two points. The first being that the negative NAO (caused by the blocking ridge in Greenland) begins driving the train. The second is the westward migration of the "evil empire" as it did during the back half of December ultimately leading us to some post-Christmas glory. The European and Canadian ensembles show strong indications of such an evolution. The American long range ensembles show a much more potent Pacific driven pattern however with much less of an influence from the blocking. The American model and ensembles have been erratic to say the least as of late and at times have performed poorly so I am inclined to favor the two other over the one. The other very important question relates to what kind of activity will we see in such a pattern. Can we move into a semi or fully split flow regime that resulted in the succession of storms in late December ? or will it stay dry. I think the former is possible since the polar jet will relax somewhat after the 22nd of the month while some energy will be allowed to undercut some of the mid and high latitude ridging in the Pacific. Its not a clear cut situation yet but I hope we can get a bit more clarity in the coming days.



Wednesday, January 9, 2013

Thaw still expected Sunday/Monday and some icing possible next week

The mountain has been hanging in there pretty good so far. The arctic cold has receded and Pacific air is largely encompassing New England. As of now, the effects of this have been minimal thanks to the deep snow, low sun angle and so far light winds. The latter of these will be the most critical in the coming days. So long as we keep the wind down, the relative warmth that has invaded the middle layers of troposphere will be unable to mix to the earth's surface. Winds will increase during the day Wednesday as an upper air disturbance and area of low pressure centered well to the region's north approach. Temperatures may creep above freezing again but snow showers will commence late in the day as the instability increases. I would expect maybe an inch or two from this followed by a dry and somewhat sunny day Thursday with diminishing winds and temperatures again near or just above the freezing mark.

The wind issue will become even more critical as the weekend approaches. Understand that the upper ridge along the east coast is mammoth in nature, easily supporting record breaking warmth in areas where the lower troposphere is well mixed (windy). Areas that are cloudy with light winds can avoid this fate. Much of Vermont will successfully do this Friday as clouds cover the state with temperatures still in the 20's and 30's. Precipitation from a decaying wave of low pressure will arrive later in the day and although temperatures will in many areas be above freezing by then, some areas could see some freezing rain. Most of this will be over with by Saturday morning except perhaps for some drizzle. I think Saturday's potential warmth could also be thwarted by clouds, of the low clouds or fog variety which would mean another day with temperatures in the 30's. Some sun on Saturday could push temps into the 40's however.

Sunday and Monday is when it could get real ugly. Higher winds, higher dewpoints, a period of rain and an extended period of above freezing temperatures will do damage to our snow. Arctic cold is expected to seep back into the region slowly beginning Monday but hardly in decisive fashion. The colder air will actually be undercutting the very persistent and still very potent east coast upper ridge. This undercutting will set the stage for a dramatic temperature gradient stretching from the Ohio Valley into New England. Waves of low pressure along this boundary, one or perhaps two of them could impact the region with precipitation. This is a battle where the cold air seems mostly out-gunned but there might be enough available to set the stage for an extended icing event next week. Arctic cold undercutting large east coast ridges does happen now and again in New England and some big ice storms have been the result. The one that comes to mind is early January of 1998 where (if I can remember correctly) members of the MRG coop volunteered to clean out all the tree damage from our beloved gladed terrain.

Eventually the east coast ridge will get pushed out and it will happen quite abruptly with some very strong Arctic chill possible for the weekend of the 19th and 20th. Ensembles have diverged a bit on the overall "favorability" of the pattern but I continue to think that the negative NAO will win the day, producing an extended stretch of rain-free weather and below freezing temperatures.

Sunday, January 6, 2013

Thaw for the upcoming weekend, but lots of promise for the end of January

The Sunday snow concludes one of the better stretches of early season skiing the mountain has seen in the last decade or so. Even in some of the big winters like 07-08, and 2010-11, big warm ups during the Christmas and New Years holiday vexed us a bit. This year, it will be a mid-January thaw that crimps our snowpack. We may however, have reached a bit of a turning point. This point being defined by the time at which I have become convinced that the building snow pack will not be completely blow-torched away by a thaw. This point being the time when we see the light at the end of the tunnel before even entering the proverbial tunnel.

Arctic chill will continue to grip the region through Monday night meaning seasonable January temperatures. The evil empire then brings its dreaded Pacific air to the region Tuesday. The deep snow cover across interior New England, low January sun angle and lighter winds Tuesday and Wednesday will keep the effects of the pattern change more on the minimal side. Temperatures will challenge the freezing mark both Tuesday and Wednesday but will not get past the mid-thirties except perhaps in the Champlain or Connecticut river valleys. The sun angle plays an especially large role here since the same set of weather parameters might yield temperatures in the 50's were this mid-March. Models have also redefined our late week weather a bit and not in a bad way at all. Instead of commencing an onslaught of mild southerly breezes and excessively above freezing temperatures, a vigorous upper air Pacific Ocean disturbance will be allowed to track across the Great Lakes and drag a limited amount of both instability and colder air to the region. Temperatures will remain on the milder side of average but snow showers Wednesday night and Thursday along with sub-freezing temperatures is much better than what the forecast looked just 2-3 days ago. Such weather does not melt snow.

The big trouble period begins late Friday and persists through the weekend. It is at this point when we get flooded with mild air and ultimately get a period of rain. This happens as the pattern becomes more amplified with a deepening trough in the west and an even more well-defined upper ridge in the east. It will unfortunately be a bit ugly as a storm system gathers steam in the middle Mississippi Valley and heads well into Quebec. The period of rain is likely Sunday, although some of this also timing could again be re-adjusted. Temperatures could get into the 50's as well, a full 30 degrees above average and enough to challenge a few records but thankfully this should not persist too long.

When trying to assess the evolution of the long range weather pattern, I have always tried to look at the picture on a grand scale and tried to pick out big features on this scale that might win the day. It is a very inexact science since not only can your own assessments be wrong but the assessments of the model guidance can also be wrong. Although the evil empire is clearly the big feature during the next week or so, the negative North Atlantic Oscillation (NAO) will challenge its dominance and eventually, in my opinion, become the alpha as we head toward the last third of January. The battle between the evil empire and the NAO could be an epic fight, especially between the 14th and 20th of the month and the fight will be manifested in the form of a few storm systems during this period. The pattern will support the return of some very cold air across the plains and eastern Rockies and will ensure that this month will be one of the eastern Rockies coldest January's in a while. The pattern however will also support the continuation of mild air across the southeast and Mid-Atlantic states.  Storm systems will form in the southern plains at the junction point of the very cold arctic air and warm moist air from the Gulf. The storms, perhaps one of them turning very potent will move toward the eastern Great Lakes and threaten to bring warmer temperatures into New England. There should be a decent overrunning surface to support some snow but too much warm air means sleet and freezing rain and perhaps even worse if a strong storm were to move well into Quebec again.

The farther we move into late January, the more favorable the prevailing forces become so although the next weekend looks a bit slushy, futures weekends appear much better.

And I almost forgot. Hockey is back

Thursday, January 3, 2013

More light and fluffy powder for the weekend

Temperatures struggled past zero Thursday but should moderate through the weekend though interior New England, specifically northern Maine, will be the nation's cold spot. Of more importance is the intermittent light snow throughout the day Friday which will likely yield 1-4 inches of very low density fluff to the mountain. The culprit for this is the last disturbance associated with the exiting polar vortex. Flurries could continue through Saturday but accumulations will be minimal and it will instead be mostly cloudy and cold with daytime temps near 20. Another weak area of low pressure will push through the Great Lakes Saturday and approach early Sunday. This is a putrid looking system but some limited moisture and its proximity to the region will allow for another extended period of light snow Sunday into early Monday. The colder temperatures will continue to support snow of the fluffy, low density variety as described above and accumulations could thus be higher ranging between 3-7 inches. This also could make Sunday or Monday a good day to reserve for MRG before we go off our own little fiscal cliff (although that might be a bit over the top).

In the last few updates, I have spent some time "dooming and glooming" about the pending adverse turn in the weather pattern. At the very least, we are in for a tough stretch next week but there are ways we can limit the damage and potentially move back toward a more favorable pattern as soon as the 14th or 15th of the month. Regarding the latter, the ensemble packages have been quite ambivalent but I am hoping the models/ensembles hash out their own little fiscal cliff deal and provide us with some sort of soft landing and although such hope can be dangerous, their are ways this could happen. More on that in a bit. The rough stretch I alluded to begins during the middle of next week and could involve 1-2 rain events between Wednesday and the weekend of the 12th-13th. There is some lingering arctic chill in eastern Canada but the weather pattern will make it very difficult to allow for any involvement. At best, the first batch of precipitation could include some freezing rain, but at some point we are going to have to face the 40-50 degree music and rain. 

The Pacific evil empire is the primary culprit behind the turn toward warmer temperatures and the likely rain. By the 12th and 13th of the month however, height rises (jet stream ridging) will expand to include the Aleutian Islands, the North Pole and Greenland. This is another ring-around-the-rosie scenario that forces some very cold air into North America toward the middle of the month. The dilemma for Mad River Glen is that the cold is favored in the wrong location - the western United States. Still, the negative AO and NAO is an appreciated ally and the GFS ensembles have responded by showing a much earlier return to colder weather and winter weather events then the European Ensembles. I think both packages of information are guilty of succumbing to respective biases but the trend today was to at least open the door for some better possibilities for the second half of January.

Tuesday, January 1, 2013

Evil Empire returns after a cold finish to the week

MRG continues to bask in the glow of a great holiday week and a remarkable reversal of fortunes to end 2012. The "basking" can continue through next weekend as the Polar Vortex rotates through northern New England this week and off into the Canadian Maritimes. Accumulating snow will be minimal although weaker disturbances are capable of bringing flurries and light snow to the mountain. The best chance for this comes Wednesday and again on Friday. We talked about some of the cold weather in the last update. Interior New England will have the lucky distinction of seeing the coldest weather in the U.S. over the coming days. The coldest period should be Wednesday night into Thursday morning with readings getting to about -10 F and struggling to get above 10 during the day Thursday. Temperatures will moderate for the weekend with readings getting close to 30 during the days. An increase in the clouds Sunday should be followed by light snow later in the day or at night as a more significant clipper disturbance brings a good chance for a 2-6 inch snow by Monday morning.

The Sunday night/Monday clipper is the best chance for the mountain to pick up some new snow over the next 10 days. The headline does not lie unfortunately. The "evil empire" is back and signs of trouble are all over the medium range models and ensembles after the 10th of the month.  The Arctic Oscillation (AO) and North Atlantic Oscillation (NAO) are expected to continue to be on the negative side of zero which is a much needed and encouraging ally in what will be a very tough fight to preserve our snow (and thus the reason the favorability index isn't worse). I didn't give the "evil empire" its name for nothing however, it is the "death star" of winter weather. Especially when coupled with a trough over Alaska, the feature not only encourages zonal flow, it favors the cold weather across the western North America. The effects of all this may not begin to impact MRG until the 10th of the month and will not be uninterrupted. Overall however, this is going to be 2 weeks of a generally adverse pattern that will continue through about the 22-24 of the month (loose prediction).

Much of the United States will be very much on the milder side of average by the end of the upcoming weekend. Canada however will continue to remain on the colder side of average for much of next week. To save the 2nd full weekend of the month we are going to need some sort of buckling in a very zonal jet stream that will allow some of this cold to fight its way back into New England. The models have yet to come into full agreement but as now they support a slow erosion of below freezing temperatures next week and a potential rain event by around the 10th of the month. These are ugly details I know, but we it would be wise to keep our expectations low for the middle of the month. Hope everyone had a happy and safe New Year.