Some snowfall late Wedneday into Thursday as December comes in wintry !

Our mountains are a few days in and about a foot of snow deep into this early dose of winter. The longer range outlook took a less than favorable turn on us, but the upcoming week still appears to be a productive one. We've been in a tight range on temperatures with just enough clouds and wind to keep readings above 20 degrees during the nights while only rising a few degrees during the daylight hours. 

That mostly cloudy sky is expected to be with us through much of this wintry week. Lighter snow showers are expected to continue with minimal accumulation through Tuesday and our best chance for some blue sky might be on a chilly Wednesday morning. Clouds are then expected to then thicken again with light snow developing in the afternoon. This is an impressive looking clipper system that is poised to bring us this burst of snow, but I sure wish we could get this sucker do dig a little harder on its southeast trajectory. Still we appear to be in the favorable quadrant of what is commonly  referred to in meteorological parlance as the "jet max" and results after Thursday night should be pretty good. A period of steady snows appears very likely, as mentioned Wednesday night, but the best snow may come late Thursday into early Friday with a plume of Champlain enhanced moisture and a beautiful cold northwest flow to blow that moisture toward us. 2-4 inches seems most likely during the first period of light snow Wednesday evening and then 4-8 inches of more elevation sensitive snow late Thursday into Thursday night. A healthy burst of early season chill will accompany this later burst of snow and Friday's temperatures on the mountain are likely to stay in the teens. 

A second clipper system, weaker than its predecessor is expected to bring more clouds and some snow for Saturday and will help extend the stretch of sub-freezing temperatures. A little early to speak on snowfall expectations except to suggest it looks higher than zero and lower than 6. 

I've been operating under the assumption we would get another week of colder weather similar to the current one and though arctic air remains a significant part of the picture, the long wave pattern appears a bit different with cold expected to shift its focus westward. The biggest concern with this change relates to the possibility of an area of low pressure taking an inland route of bringing warmer weather and a spat of rainfall. There are a couple of different directions this could still go and models have been painting a variety of possible outcomes though the one early Monday appeared warmer unfortunately. 

Another round of sub-freezing temperatures is expected to follow whatever scenario happens early in the week before ensembles indicate another potential western North America jet amplification for the 2nd full weekend of December. Still some good news in that we are not going to lose the support of a more favorable Pacific jet stream. Additionally, ensembles indicate ridging over Alaska which should keep arctic air well-positioned to envelop much of Canada. We are way, way behind with Hudson Bay ice so far this cold season with less than 5 percent of that northern body of water showing ice cover as of December 1st. The Hudson Bay has been freezing later in recent years thanks to the impacts of climate change, but even with these headwinds, 20-30 percent of that 500,000 square mile region should have ice by now. The presence of arctic air should help reduce the open water over the next 2 weeks. 

Terrific early season weather pattern prevails through at least the middle of December !

Beautiful Thanksgiving snowfall in northern Vermont was scenic and brought us a step closer to opening day. It appears Sugarbush has a tentative opening planned for December 1st but I have no inside intel aside from what the website is showing except to say that favorable snowmaking conditions will continue for the upcoming week and beyond. 

The prevailing west flow encompassing both the eastern Great Lakes area and all of New England is a dry one for Vermont. The lake effect snow bands tend to ring themselves out over the Adirondacks and the moisture from Lake Champlain is typically deposited in areas from Stowe northward. The high country will remain sub-freezing atop our new found late November snow, but addional snow showers will be light through the weekend and I would extend this outlook through much of Monday. Temperatures on the mountain will stay within a 10 degree range of 15-25 and generally below 20 in summit locations through this time in spite of some limited sunshine. 

I've been looking for that flow to turn more northerly and tap into some of that relative warmth from Lake Champlain and the opportunity for that, though limited, appears on the forecast maps Monday evening into Tuesday. If we can get a few inches, it would be of the very powdery and fluffy variety accompanied by temperatures in the low 20's. Those wintry readings will continue into the later part of the week when a much more impressive looking clipper system brings us our next decent show at some significant snow late Wednesday into Thursday. This storm has the capability of attaining some additional strength as it interacts with the warm coastal waters of the Atlantic Ocean and this opens the door for some higher upside potential. A more significant chunk of early season arctic cold will then envelop Vermont on Friday and into the first full weekend of December. Daytime temperatures might fail to break 20 degrees either Friday, Saturday or both. 

The pattern overall appears supportive of colder weather for the first half of December thanks again to favorable jet stream conditions in the Pacific. The American Ensembles shift some of this colder weather westward around December 14th/15th. By contrast the European Ensembles manage to keep some of the ridging structure alive in western North America while the weakened Pacific jet conditions are shown to at least somewhat persist. Even the possibility that the colder could persist beyond the 15th would suggest one of the best December setups in years for Vermont ski country. 

8-14 inches for the Thanksgiving holiday and yes, not all the forecasts agree with this yet !

Our white Thanksgiving is on track and on target. Over the past 24 hours and especially in the last 8 of those hours, models have converged on a scenario only slightly different than the one I proposed a few days ago. If we allow for one more northward nudge, a foot of snow is likely for Mad River Glen and Sugarbush. The National Weather Service in Burlington does not totally agree with this thinking and the point and click forecasts for the Waitsfield covered bridge are indicating less than an inch of snow for Thursday with the same Thursday night. Though this would seem to indicate that us weather people are not on the same page, we aren't too far apart either. NWS has central and southern Vermont painted in a Winter Storm Watch and this extends as far north to southern Washington County, but not quite to Waitsfield or Warren. I wouldn't worry about it as I think they will make a more favorable adjustment before the end of the day. 

Snow should begin in the vicinity of 8 or 9 am on Thanksgiving and fall at a rather steady rate through late in the evening. This a a very garden variety Vermont snowstorm with a benign area of low pressure in the Ohio Valley gathering a bit of fuel on the Atlantic Coast and depositing a swath of snow across central New York and interior New England. The one adjustment I would make relates to the snow consistency. Temperatures do not support a powdery snow in valley locations and will be hovering around the freezing mark through much of the day. Readings will be closer to 30 degrees around 1,600 feet (MRG base) and 25-28 closer to the summits which does support a drier snow. The moral of this story is to prepare yourself for varying snow consistencies if you venture out. I continue to expect snow accumulations of 8-14 inches. The heaviest area of snow might be south of MRG but I expect at least a 4 inch snow as far north as Stowe so I am surprised how bearish the snowfall forecast from NWS looks for some of these areas in northern Vermont. Again, I would fully expect them to adjust  by the end of the day or early tomorrow. 

A pattern supporting a widespread area of below normal temperatures in eastern North America remains on target beginning this weekend and persisting through much of the first half of December. What a sight to behold watching the EPO crash deep into negative territory the way it has for the back half of this month. There are a lot of warm feedbacks that need to be dealt with stemming from the onslaught of warmth that has persisted through much of 2024. Much of eastern North America will be enveloped with colder weather for the next 20 days giving us the opportunity to neutralize much of this as we proceed to the core of the cold season. 

Divergent westerly flow in Vermont will give the region an opportunity for some sunshine both Friday and Saturday. Most of both days will be sub-freezing with the exception of the afternoons in valley areas. Over the mountains, light snow showers and flurries will be more prevalent though accumulations will be minimal and confined more to the snowbelt areas of New York state and Jay Peak which tends to do better with west or southwest flow. More clouds and a period of steadier snow are possible for Sunday as the flow turns north. Temperatures will then remain in the teens and 20's for the first week of December with snow possible from a weak clipper on Wednesday and perhaps a stronger one later in the week.

Thanksgiving snow and plenty of early season cold weather to follow through early December

 A beautiful early winter pattern stands directly in front of us as the thanksgiving holiday approaches. It's been a struggle in New England to sustain any type of below normal temperatures over the past year, but an excellent stretch of cold begins Tuesday evening thanks mostly to a very favorable EPO set up in the Pacific and some high lattitude blocking over the northeastern Eurasian continent. The best part of this story is the snowfall which comes in the form of a significant dose on Thanksgiving and this storm will give the whole region a very wintry feel that will extend well into December thanks to the pattern. 

A moisture-starved storm will bring some rain and mixed precipitation to much of Vermont as passes over the Ottawa River in Canada early on Tuesday. Some snow can be expected close to the Canadian border but not much south of that. Drier and colder air will then settle in Tuesday evening which will begin what we hope is a multi-week stretch of sub-freezing temperatures on the mountain. Such an occurrence isn't easily achievable in the middle of winter and is a special sort of challenge in early December. 

Our Thanksgiving storm gathers its moisture Wednesday over the Midwest and will continue to strengthen as it moves over the Ohio Valley during the evening. Models continue to jostle over the track which is a bit surprising at this stage in the game, but I feel very comfortable betting on the Euro output which places Vermont in one of the better areas for snowfall on Thursday. Northward shifts are always a good bet, but are especially likely to happen early in the season thanks to what is usually a weaker polar jet and thermodynamic feedbacks from the Great Lakes. This track, would place the storm just west of the New Hampshire seacoast for Thanksgiving dinner and then up through eastern Maine after that. A classic holiday snowfall would be the result, beginning early on Thursday and continuing well into the evening. The snowfall would be widespread, falling both over valley areas along with the high country with elevation impacting snow consistency more than anything else. Some mixing with sleet and or freezing rain is a very real possibility early Thursday evening. Those details need to be ironed out in a day or two. In the meantime we can establish some early snowfall expectations of 7-15 inches. Without the mixed precipitation threat, I would go higher, but I expect a powdery finish to this storm regardless with a chilly, wintry and snow showery Friday (even though the accumulating snow should remain closer to the Great Lakes). 

A weak mid latitude Pacific jet set up (synonymous with -EPO) will combine forces with the aforementioned high latitude blocking scheme with the trifecta support coming from ridging which is expected to develop in western North America over the next week. This means cold weather through December 10th that will undoubtedly be accompanied by additional chances for snow. Almost all early season cold setups produce snowfall in northern New England and I would fully expect multiple chances at some snowfall next week. Champlain enhancement will contribute as might a storm that models have yet to resolve. A very encouraging start to the season which will produce plenty of snow clover, snow showers and sub-freezing temperatures as Mikaela Shiffrin skis for her 100th win this weekend at Killington this weekend.

Winter Outlook 2024-2025 arrives just in time for a colder pattern change

2024 has been the year of persistent warmth and following 3 flooding events over the past 18 months, autumn suddenly turned very dry. We thus head into the upcoming winter in need of some precipitation of off all types to avoid running a further drought deficit.  Though they're a few encouraging signs out there in the outlook, one rather bad one looms over everything. In the mean time, the short range outlook appears very encouraging with snowfall in the forecast over the high country over the next 5 days and more snow and cold on the horizon around the Thanksgiving holiday and beyond. With that introduction, lets take the plunge into another season. 

Upcoming Snowfall 

Going to start by providing a brief outlook for the upcoming storm, a system that is certainly not atypical during the early or later part of the ski season and one that is very reminiscent of a few of the bigger events from last year. While low pressure is stalling out over southern Manitoba, there will be an extended opportunity to gather moisture from the Gulf of Mexico and Atlantic Ocean which will give rise to a more robust coastal low pressure center late Wednesday. Rain will enhance and spread very slowly northward. When precipitation finally arrives midday Thursday, the deeper occluded low will swallow the coastal system allowing the already marginal temps in valley locations to warm a few more degrees and this means mostly a rain event in low lying areas (at least at for a while). Way up above 3,000 feet, precipitation is likely to fall as some wet snow late Thursday and continue through Thursday night but even at this elevation, temperatures are marginal and only support a few inches of very wet snow. Forecast models then are indicating a break in the action before an additional colder round of precipitation arrives for Friday night into Saturday. This should produce snow everywhere (even on the valley floor) though heavier snowfall amounts will remain confined to the high country and the more powdery snow should stay above 2500 feet. Still, the snowfall is expected to persistent at least intermittently through Sunday and where temperatures are the coldest, closest to the summits, snowfall should pile up modestly. By Sunday evening, expect 4-day totals of upwards of a foot while a 1-3 very wet inches can be expected near the valley floor. There is better dynamic support for heavy snowfall over the Catskills of New York and Pocono region of Pennsylvania on Friday. Much of this will melt early next week and should provide some needed drought relief to some very dry areas of the northeast. 

 

I have some deep concerns about the EPO this winter and the presence of the dreaded evil empire in the Pacific Ocean, but its not showing up in the outlook through the rest of November into early December. Quite the opposite is in fact, with a favorable jet stream in the Pacific, opening the door for stronger shots of cold weather and additional snowfall around the Thanksgiving holiday and into the first week of December. We discuss all this in subsequent posts. 

ENSO Outlook

In the meantime, lets start with discussing the ENSO situation for the winter. This is one key area where we are exceeding some of the more dire expectations earlier this year. Following last year's strong ENSO event which was approximately a +1.7 C El Nino, the exceptions of a nearly equally strong La Nina appeared to the prevailing view of those that both follow and prognosticate on ENSO. Sea surface temperatures in the equatorial regions of the Pacific have certainly trended in that direction, but after tiptoeing into negative territory, sea surface temperatures have stabilized and have headed back to near neutral levels. This has defied conventional wisdom. The last forecast I read from the NOAA folks continued to predict a weak to moderate La Nina, but I have very little confidence in such an outcome and would favor a more neutral ENSO as a best guess for the winter at this point. 

We certainly could use all the help we can get from ENSO neutrality. Many of the coldest winters, especially since Y2K have occurred during these ENSO conditions including the 2002-03, 2003-04, 2013-14 and 2014-15 and some of the biggest torches have occurred during strong ENSO winters of either the El Nino or La Nina stripe - think 2011-2012 and 2015-16. Boy, I would love forecast a cold winter on this rationale and its certainty tempting to run with this as the medium range outlook continues to trend colder. I can't do it however and the following paragraphs detail as to why.

PDO Outlook

Those that have followed the blog might remember that I keep referencing this current adverse -PDO stretch we are in. 2018-2019 was the last relatively neutral PDO winter and was also the last time we had a complete freeze of Lake Champlain. Since then the PDO has become more and more negative with each successive winter. This past October, the PDO nearly set a record recording its second lowest October reading, -2.48. in a dataset spanning over 100 years and a top 10 lowest readings for any month. 

 

The Pacific Decadal Oscillation or PDO is an index that describes the configuration of sea surface temperatures in the mid-latitude Pacific. No, it is not the defining predictive indicator every year, but the continuous negative state keeps relative sea surface temperature warmth in the mid-latitude Pacific with relative sea surface temperature chill both in the higher latitude areas near the Bering Sea and near the Equatorial regions (which would power La Nina, if it were to ever occur). This type of configuration does not encourage the sustaining of favorable jet stream conditions in the Pacific and instead favors the tighter jet stream flow that has a propensity to repel the southward transport of arctic air. There is a nice illustration when comparing October SST's of this current year to those that prevailed before the last cold winter we had in 2018-2019. 1st map shown is 2018 October and the 2nd is the most recent October.

 

PDO indices are cyclic by nature and this current more adverse stretch will ultimately cycle into something else. The PDO is also a better (and certainly not perfect) predictor of temperatures as opposed to snowfall. For coastal areas of New England and the Mid-Atlantic another year without the more constant presence of arctic air is a good enough reason to predict another bad snow year, but many of these years end up being respectable across interior locations as has been the case over the last two seasons. 

Snow/Ice Expansion

The buildup of snow across the northern hemisphere is running about average. The October value came in at 18.88 millions of square kilometers which is right in the middle. The buildup of ice in the arctic is slow relative to average but it remains faster than 2016 and 2020. The arctic refreeze time continues to trend slower over the longer term and this IS a direct result of climate change. Every 5 years or so, there's a noticeably larger area of open water that needs to refreeze and the Hudson Bay, which remains 99 percent unfrozen as of this outlook, has open water later into December. 50 additional years with this trend will have a dramatic impact on the personality and climatology of our winters in particular. I hear the skeptics refer to some obscure prediction made a quarter century ago about ice in the arctic and how it was predicted to be ice-free by now. I never saw such predictions at the time, but the changes that have occurred have been dramatic enough and ultimately will lead to an ice-free arctic sometime before the next turn of the century or early in the next one. 

In the meantime ice and snow are building in the northern hemisphere in comparable fashion to what has taken place over the last 10 years and without El Nino to ravage the high latitudes, there should be a better expanse of arctic chill over Canada this year when compared to last. 

What is the weather telling us ? 

My atmospheric tells section is the part of the outlook where I go through the exercise of examining recent weather trends as a means of predicting the future. Undoubtedly there's been some distinctive traits to the recent weather conditions that will help guide us. 1) It has been persistently warm in Vermont. The last time we've had a below normal month was November of 2023, a year ago. The combined impact of the -PDO and climate change haven't helped in this regard but it would be hard to expect any change in this basic theme without help in the form of different forcing mechanisms in the Pacific . We are getting a bit of help from the neutralized ENSO and let's all hope it provides some material impact. 2) It's been very dry over the past 90 days. Southern New England had a historic flash flooding event back in August and Vermont had a similar such event in July. September, October and November have been extraordinarily dry and sunny most areas have not had an event with an inch or more of rain on a calendar day since August.

Digesting all this and comparing these recent observations to previous seasons points you to one similar year in particular - 1964. That autumn featured dry weather in New England, had a building weak La Nina and a negative PDO. Northern Vermont got sporadic bouts of extreme cold but was decidedly below normal on snowfall and Burlington, VT in particular saw one of the lowest seasonal snowfall totals of the last 100 years. Since MRG opened back in 1949, there's been two other bigger negative PDO spans and some of those winters had very good results for northern New England especially on the snowfall side. The last two winters, though certainly warmer than the 1950's or 1970's, saw respectable snowfall amounts, especially over the high country. The king of all negative PDO winters, 1955-1956 was a more respectable snow season and certainly a colder one winter overall.

The Outlook Summarized 

My outlook for upcoming winter shows considerable amount of respect for the near record autumn negative PDO values. I can conjure up some optimism on the snowfall side, and I'll conclude with that more upbeat sentiment, but I expect us to struggle sustaining colder weather in eastern North America. We will have to hope that the ENSO-neutral to weak La Nina setup can allow cold to encompass a greater expanse of southeast Canada and that some of this cold can continue to keep winter in place across northern Vermont even as areas farther south are struggling.  It's encouraging to see a looser Pacific jet stream set up in the medium range outlook and this should help get us closer to an opening in the near term, I just have concerns about whether such a pattern can sustain for more than 2 weeks. Over the course of the winter, temperatures are likely to be colder than what we experienced during the strong El Nino winter last year but should remain considerably above average. In t this case I would prognosticate 2-4 degrees F above this average over the 4 month stretch beginning in December. I am more optimistic on snowfall side, especially for the possibilities of an upside surprise. If I had to pick a range on snowfall I would choose the 150-175-inch sub-optimal total both recent and more distant -PDO winters have been more generous and I think another over-performance is very possible, especially relative to coastal areas. Lets hope the next few weeks get us off the ground figuratively and on the mountain literally. Enjoy the upcoming season !

 

The 2023-2024 winter, it's ups and downs and fairy tale ending !

What a crazy winter 2023-2024 evolved into. It was persistently warm after November, as many winters have been during this recent negative PDO cycle combined with the additional push in the background from the impacts of climate change. Unlike the 2015-2016 Super Nino debauchery, it was snowy and there were periods of deep snow cover on the mountains both early, middle and later part of the winter. It all culminated with the incredible resurgence of winter in March and early April. I apologize for the overuse of sports parlance in the blog, but has Vermont weather ever had a more clutch weather performance in the 75-year history of Mad River Glen than what occurred  in the first 8 days of April. The elusive April 2-foot snowstorm happens and then mostly clear skies for solar eclipse viewing was like hitting two grand slams in the same inning. I still have trouble believing it actually happened ! 

As expected, the strong El Nino was the most critical driving factor locally, nationally and globally. With the exception of Alaska, North America was warm as a whole and the area comprised of the Great Lakes, Upper Midwest, Northern Plains and Central Canada was historically warm. Strong prevailing westerlies in the jet stream made it difficult for pools of arctic cold to build, expand and push southward. Clouds were very prevalent especially across the eastern U.S. and this acted as a blanket during the long overnights. Just quickly glancing through some daily weather data, it is very evident that clouds and warm overnight low temperatures statistically powered the milder than average temperatures throughout the winter over a broad area, New England included. 

For the purposes of a weather blog, I try and simplify things with nonacademic analysis (don't think i am capable of anything else anyway) and lots of context. With that mind, we can assess the strength of the recent El Nino with one number, a SST anomaly in a critical region of the equatorial Pacific. This came in at +1.69 C this past winter which makes it substantially weaker than the +2.28 C El Nino of 2015-2016.   We certainly know that the recent winter was a lot snowier than 2015-16, but it was only marginally colder by about 1.5 degrees F during the period beginning in November and ending in March. If you throw April in there the difference would certainly increase. Every significant El Nino brings global temperatures up and when added to the impacts of climate change, the warmth will set monthly land and sea temperature records and set off alarms and this certainly happened this winter. It is common for a healthy El Nino event to warm global temperatures by a very statistically significant quarter of a degree C. This allows the climate denialists to play their favorite game. Take a big El Nino from 30 years and compare it to a recent neutral ENSO winter and like magic, one can make our warming global temperatures disappear ! Climate change, by way of comparison is warming the earth by an estimated few hundredths of a degree C annually, which is scary, but still can very overpowered by a strong ENSO event, particularly an El Nino. 

A bigger distinction I have made regarding this recent El Nino was the state of the PDO. More typically, El Nino's are accompanied by a positive PDO state in the Pacific though it is not an especially dependable rule and there have been exceptions, this year being one of them. The -1.11 and -1.02 PDO that was posted in November and December respectively represents a PDO in a decisively negative state. As the winter progressed, that number weakened but remains slightly negative as of April and has been so now for every winter month dating back to December of 2019. The word decadal is used for a reason and the state of the PDO comes in streaks that can extend out to a decade in length. What makes the recent streak a little more unusual is the persistent negative strength of the PDO which finally weakened to -0.41 as of March, the weakest its been in any winter month since 2019. I bring this up because, I've been of the opinion that the PDO has made weather pattern life a little difficult in Vermont during both this and other recent winters. It has been difficult during this stretch to maintain a cold, wintry pattern for longer than 2 or 3 weeks and the El Nino further limited the reach of arctic chill across both North America and Europe. All that said, it was also my opinion that the PDO would provide us with an assist on snowfall and help guide storms in our direction at the expense of the coast. This turned out to be true and we ended with the warm and snowy winter that was advertised. 

So lets go through it ! November was one of the two months in 2023 that saw below normal temperatures, in Vermont. It also was a month that foreshadowed the personality of the forthcoming winter almost perfectly, especially the March and April section. Snow whitened the mountains initially on November 8th and a cold ensuing week kept that snow in place for several days before a mid-month mild surge melted it away. More snow and cold returned in the days before Thanksgiving and much of it survived through the holiday and weekend when Killington hosted the World Cup skiing events. Three significant elevation events got the lift service part of Vermont's ski season off the ground over the two weeks between November 26th and December 11th. I scored a good forecast over the National Weather service on the first one, Tim Kelley of Jay Peak owned me on the last one and the high country of northern Vermont was in amazing shape in terms of building an early season base. The first event on November 26th-27th resulted in widespread power outages, but the snow was mostly powdery above 2,500 feet. We saw this repeat on numerous occasional throughout the winter and especially during the spring. It was the most elevation sensitive snow year I've experienced in the 20 years of doing the blog. The 2nd event which begin on Sunday, December 3rd had better cold air support on the back end and modest snow though a little less than I had anticipated. The third event really too me by surprise as the pattern appears poised to turn mild by December 10th, but the storm in question managed to entrain enough cold while re-consolidate along the New England coastline. Rain turned to snow by Monday, December 11th and its often events such as those that really make you think the winter would serve up something special. 

 

Once again, just when it seems that nothing can go wrong, it all crashes to the ground. The weather pattern did indeed shift and arctic air went into retreat mode as the Arctic Oscillation (AO) turned very positive. I've lost count of how many iterations of this movie we have seen in Vermont.  An amazing week of weather in the early or middle part of December gives way to a lousy, rainy holiday. In this version, the rain came, way too early, fast, heavy and was accompanied by the ugly combination of wind and high dewpoints. The 2nd of two major flooding events in 2023 hit the state on Monday, December 18th. bringing local rivers above flood stage and causing more damage to low lying areas. Much of the snow melted away, though some did remain across the highest elevations. The holiday weather was dominated by clouds, rain, mild weather and some of the worst skiing of the season. The start of 2024 was to start almost from scratch though MRG managed to keep it going in limited capacity, throughout this very ugly stretch. 

Bridge St, Waitsfield - December 18, 2023

January of 2024 wasn't exactly an epic month, but was a nice bounce-back from the holiday. Jet stream blocking at high latitudes powered the AO and NAO well into negative territory for much of the first two thirds of the month and arctic air became a significant part of the weather picture during that stretch. Garden variety cold early in the month set the stage for a nice dry snowfall on the first Sunday of 2024. I had higher hopes for the subsequent storm around the time of January 10th and 11th, a really juicy southern streamer that was consistently predicted to track toward the Great Lakes and bring a surge of milder temperatures and rainfall. I recall thinking that the downstream blocking would ultimately win the day and possibly turn this event into a big snow producer. The southward shift never materialized really but the snow fell anyway, a heavy base building event that exceeded even my lofty expectations. Another snow/sleet conglomeration early on the MLK holiday weekend added more density to an already hefty snowpack ahead of what would be the coldest period of the year. 

The arctic outbreak in the middle of January generated a lot of news and was especially intense over the western high plains and then the central plains and Texas. It brought -10 degree temperatures to Kansas City for a NFL playoff game, but the coldest temperatures recorded in the MRV were in the vicinity of -5 that week which marked the coldest readings of the season. That is the warmest "coldest day of the winter" I can remember and a more rigorous academic analysis might show that the 2024 winter featured the least amount of extreme cold in recorded history in Vermont. Still, the week beginning January 15th was chilly and snowy with snow squalls finally giving skiers some dry more skiable friendly snow. Arctic air went into retreat mode beginning January 22nd but we still managed to squeeze out some winter weather over the last 8 days of the month including some mixed precipitation around the 25th and some snowfall on the last Sunday of January. 

February was a very different kind of month relative to the other winter months in 2023-2024. It was mild much like December but also very dry unlike December. Most of Vermont, even the mountains, saw less than an inch of melted precipitation which is way below average. The dominant weather feature was a jet stream ridge, a very large one, that established itself not far far from the same area that received the arctic cold. The result was a blow torch across the central part of the North American continent with excessive temperatures stretching well into Canada on multiple occasions. The torching wasn't centered over Vermont so although it was milder month, we managed to avoid a total scouring of our snow pack. There were several instances where the torching enveloped all of upstate New York and the Adirondacks, making it as far east as the Champlain Valley only to stop at the Long Trail. This happened on 2 days early and then again later in the month. All that said, it was a quiet month from the standpoint of storminess and this allowed for more sunny days and better visibility following a brutally cloudy December and January. 

I can recall two moments when both the weather conditions and projected weather pattern going forward appeared especially bleak. The first was the December 18th flooding since that event was coupled with the realization that another Christmas holiday was going to be mild, damp and dreary. The 2nd and an even worse moment came during the back half of February. Though colder weather and a bit of new snow finally buried the crust, the EPO index surged in later February and forced any arctic air back into retreat mode while providing western ski areas with a barrage of storminess. With less than 2 feet of snowfall in February, and mild air melting much of that during the last  6 days of the month, winter 2024 appeared poised fade out altogether by early March when more mild weather was expected to arrive. Indeed, the torching in the Midwest was relentless with 70-degree temperatures surging into the Great Lakes on multiple occasions. Once again, that mild air would push eastward into the Champlain Valley and then abruptly weakened before crossing the Long Trail. It was an ugly scene around March 8th with, only limited terrain surviving at MRG, but the weather pattern took a dramatic and surprising March turn as split flow emerged in the jet stream overall while a storm system manage to defy the conventional wisdom of what typically happens with such an energetic Pacific Jet Stream 

The Monday March 11th event was probably the best of the season and it also marked the beginning of an incredible late season 4-week stretch. Though it didn't quite land on the  Ides of March storm, the 30 inch snow on March 11th was yet another season saving event and one that followed a miserable stretch of weather. The initial storm took shape while all of New England was enveloped in mild air and this event would have brought more rain were it not for the ability of robust southern branch energy  in the jet stream to re-consolidate the storm over the Mid Atlantic. Cold air was limited but the newly energized coastal system managed to suck enough cold air to create a powdery event for the northern Green Mountains. It was the first of many very elevation sensitive events over this stretch with only a few gloppy inches falling in the Champlain Valley. 

 

Following a succession of more spring-like day prior to St Patrick's Day, the weather pattern turned cold as blocking reemerged at high latitudes, mainly over upstream areas of Alaska and portions of the Arctic this time. Both Sugarbush and Mad River Glen were hit with snow squalls on multiple days beginning on the 19th. It was fascinating weather actually because any snow that fell in valley locations would melt with a few hours of partial sunshine while the snowfall continued to pile up over the mountains with fresh powder on a ski succession of days. A reinforcing shot of even colder air enveloped northern New England appropriately on the first day of spring. This was timed perfectly with an incoming weather system that produced widespread snow for the entire state of Vermont on Saturday March 23rd. This was probably the least elevation sensitive event of the season and one of the coldest with over a foot of snow falling at MRG atop the powder that fell during the week.

The receding El Nino and weakening PDO certainly seemed to help revive an ailing winter season, but who was to expect what was to happen on the first full week of April. It's hard to get Vermont weather to cooperate fully in any season and the only good bet for April typically is clouds and mud. After a pretty innocuous start of the month on the 1st and 2nd, with afternoon temperatures approaching 50, colder arctic air moved south out ahead of a big approaching late-season winter storm. Like many of our bigger snow producers, a good snowfall was contingent on a strong low pressure area located over Lake Michigan, transferring energy to an ideal coastal position and then having that storm lead us to glory. There were some questions as to how efficiently that transfer would take place but it all worked out in the end with heavy snow falling on April 4th while conditions continued to turn colder as snowfall piled up. The snow over performed on the front-end but disappointed a little on the back end with snow showers confined to the Adirondacks at the expense of the northern Green Mountains. Still, the elusive April storm was in the bag and the snow was deep from top to bottom, albeit a little dense at the bottom. 

Like magic, clouds vanished on Sunday April 7th making for a beautiful spring day of skiing atop almost two feet of new snow. Clear skies continued for the big day on April 8th and the scattered high cirrus clouds remained scattered creating a near perfect situation for the solar eclipse. Lots of corn snow, terrific visibility and afternoon temperatures in excess of 50. Just an incredible stretch of weather in what is typically not a very incredible time of the year. Clutch !  

 

The season concluded with well over 200 inches of snow at most of the northern Vermont resorts and well over 300 inches at Jay. What stands out more about the 2023-2024 winter was the elevation sensitivity of most of the snow. Burlington which serves as the most reliable first order station in the state recorded 61 inches of snow, well below the normal 87 inches. Meanwhile, the Mt Mansfield snow stake peaked well above average, recording a depth of over 90 inches prior to the April 8th solar eclipse. Warmth centered over the Midwest/Great Lakes/central Canada region and even stronger warmth across western Europe was another major headline. The strong El Nino is a known contributer to high latitude warmth while climate change continues to push land and sea temperatures higher. With all these warm weather headlines, it might seem as if it wasn't cold anywhere in the world and that's not quite true. Portions of Scandinavia had a cold winter while eastern areas of the Eurasian Continent saw multiple outbreaks of brutally cold air. I bring this up because SST forcing in the Pacific, stemming somewhat from the state of the PDO has been very unfavorable for North American cold in recent winters. I was encouraged to see the PDO index weaken over the past few months and hope we can go into next season in a more neutralized state. The extremely positive PDO values have been a consistent theme over the last several winters and when added to the headwinds of climate change and a big ENSO year (in any direction) attaining sustainable cold weather is challenging. With that, I can sign off for the 2023-2024 winter. Hope everyone enjoys the summer weather and returns to MRG in good health for another good ski season in 2024-2025 ! 

Snow showers will continue with a final round Saturday afternoon while Monday weather continues to appear outstanding

It never sat right with me that Mad River Glen hadn't recorded the two-foot April storm that seem to occur so frequently in March. Climatologically speaking, it feels like something that should happen once or twice a decade and yet it hasn't in the 20 years I've been doing this, that is until the last two days. It's a challenge to overcome the power of the April sun angle, which, even with temperatures remaining below freezing on the mountain, managed to make for some wetter snow conditions below 2,500 feet. I thought we might perform better Friday with the snow shower machine, but the disorganized remnants of our recent storm's moist conveyor targeted the Adirondacks and only grazed parts of the Green Mountains. Still this is expected to continue for a time Friday night, break for a bit early Saturday and then more snow showers, some heavy, appear likely Saturday afternoon. Temperatures on Saturday will behave much as they did Friday. Sunday is expected to be a little warmer with the snow having departed and sunshine making a late day appearance. When will the corn show up ? That typically happens after the wet snow gets a chance to freeze with a chilly overnight and subsequently softens to corn with a warm day. Very good chance that happens on Monday, but parts of the mountain could see that on Sunday as well. 

Solar eclipse Monday just looks outstanding and we are almost figuratively and literally in the clear. 25-30 degree temperatures in the morning will become 50-55 degree temperatures during the afternoon and almost 60 in valley locations. We should see clear blue skies in the morning and light winds. 3 computer simulations and one package of statistical guidance suggests that sunshine continues through evening. 1 computer model simulations brings a thin layer of high cloudiness to Vermont Monday afternoon. Not every run of this European model has suggested this outcome, but it was suggested Friday afternoon so I don't want to mislead the reader and guarantee good viewing. The potential clouds are the innocuous high cirrus kind, blowing off the top of a rainy weather system in Wisconsin. They would have to power jet stream ridge to our west which doesn't seem likely to me yet weather will always manage to suprise you. 

Following our eclipse day we will take another big step into spring. Cool high pressure will slip in from for the north after Tuesday, putting a stop to the 50-60 degree weather. That said, we are looking at a lot of above freezing temperatures and a surge of warmth and potentially heavy rain Thursday night into Friday (April 11-12). We will have to keep an eye on this one for flooding because the mountains have some deep late season snow pack and this system late next week is capable of bringing high winds and higher dewpoints with it. Cooler weather is being advertised on the ensembles after April 13 and that should include some below freezing overnights even if our days continue to see a mix of 40's and 50's.