Tuesday, November 28, 2023

Stretch of wintry weather continues with more potential snowfall early next week

Though we could not quite replicate late November 2018, the coverage and depth of snow across the high country is really fantastic and I got a first hand experience in it Tuesday ! The Sunday night snow event was terrific, delivering over a foot of snow and much of it coming within a few hours.  We managed to dodge a lot of the heaviest snow squalls Tuesday, but we remain in the midst of a nice stretch of sub-freezing temperatures that should persist through Thursday. 

There are some milder days mixed into the outlook over the next two weeks but excessive torching does not look like a concern. Just as temperatures make a push toward the 40-degree mark on Friday, colder air will make a southward, reinforcing push accompanied by clouds and possibly an additional round of wet snowfall. Clouds are expected for much of the remainder of the weekend and more snow or a snow/sleet conglomeration is expected by as early as late in the day Sunday. 

There's been some excitement surrounding the event for early next week with a few of the model runs showing a healthy, consolidated storm along the southern New England coastline. Another more commonly indicated scenario is for a more disorganized storm and lighter snowfall amounts. Either way, I am pretty convinced this will be a mostly frozen event with the worst case scenario involving a compressing period of sleet. The Greenland blocking is just beast-mode this weekend and although this feature is expected to weaken next week, it will have the impact of keeping the Monday 12/4 event, safely to our south. Conditions could dry out next week if the storminess shifts southeast as some models indicate or we could see some limited instability get put to use in the form of snow showers. Temperatures will sneak above the freezing mark across valley locations but the outlook for the high country looks very sub-freezing next week and that's fantastic with MRG announcing a Saturday 12/9 opening day! 

Speaking of Saturday 12/9, early indications are for more sunshine than clouds with moderating but not especially mild temperatures. Some hints that another weather system could approach for Sunday and this would obviously bring more clouds for the 2nd half of the weekend. The most threatening part of the outlook for the next two weeks is the chance that we manufacture some sort of warmer precipitation event around  the time frame of 12/11. The Euro ensembles are hinting at this, but they are off in their own little corner as other models aren't handling that situation the same way. More generally, the pattern looks decent, powered by the Greenland block/negative NAO situation through the weekend and though we lose most of that by late next week, I am very, very encouraged that the Pacific appears cooperative as we move toward the middle of the month. There are no indications of any type of angry mood with the jet in the Pacific jet this will allow cold continue to build across Canada and stay involved in the day to day weather situation in Vermont.

Friday, November 24, 2023

November to finish wintry with some wet snow early on Monday and chances for fluffier snow after that !

I tried not get overly distracted with short term weather when constructing the seasonal outlook, but I am free to do that now. There have been a few El Nino events in recent years that have featured a blowtorch December and I am feeling better and better about the notion that this will be different. It certainly appears very different in the coming week with plenty of winter weather to talk about and a potentially decent event to start the upcoming week. 

Some early season arctic air enveloped the state of Vermont as of early Friday with snow showers dusting much of the northern Vermont high country. Earlier this week, temperatures dropped to 10 degrees in a few spots and clearing skies and slackening wind speeds will allow for the same to occur by Saturday morning. We can then look forward to a nice early season winter weekend with healthy amounts of sunshine and near 30 degree temperatures on Saturday followed by a cloudier though still a good visibility Sunday with readings climbing into the 30's. 

A couple of weather systems now appear ready to converge and consolidate into a respectable storm by Monday, November 27th. The cold air which is firmly entrenched as of Friday will become a bit stale by the end of this weekend temperatures in the lowest several thousand feet can be called "marginal" as a storm begins this consolidation near the Jersey shore. For now, I am of the opinion that our little section of Vermont will be on the right side of this marginal classification, but it's a close enough call to be impacted by any additional forecast changes so stay tuned. This means that snow should begin in the Mad River Valley late on Sunday night and continue for several hours into Monday. This storm appears garden variety in nature and won't reach a peak maturation until most of the snowfall has left us. We also have to leave the door open for alternative types of precipitation Sunday night, but again, I am of the opinion we can minimize this. If you live in the Champlain Valley however, I certainty wouldn't make that statement. 

We have another surge of early season polar air in the wake of Monday's storm and with it comes a really impressive pool of low level instability. Whether it be the Great Lakes, Lake Champlain or even the largely unfrozen Hudson Bay, all are capable of providing moisture in this type of environment and it gets deposited as snowfall in the Vermont high country. For Mad River Glen and Sugarbush, the amount of snowfall is highly dependent on the wind direction. Northwesterly flow can produce really impressive snow totals while westerly flow helps out areas like Stowe, Smuggs and Jay Peak more. Models agree on a mostly westerly wind Monday and then we try to turn those winds more northwesterly on Tuesday though models disagree on how much. Still we will have the opportunity for some substantial additional snowfall especially on Tuesday. My early guess on all of this is a 3-6 inch dense and wet snow Sunday night and early Monday and 2-6 inches of additional fluffier snow later Monday into Tuesday. 

Model simulations, for the time being, are bullish on a clipper system providing some additional snowfall Wednesday night into Thursday but the clipper has been tough to bet on in the longer range outlook so I would anticipate expectations to evolve over time. Subsequent to this is some indications that the cold will soften for the first few days of December but this appears temporary as the NAO index is expected to fall. Indications are that the jet stream at high latitudes will be somewhat blocked for the first full week of December. A current face value snapshot does not suggest an overwhelmingly cold first 10 days of December, but playing fields appears inviting for an early season winter storm and there have been indications of such on a few of the longer range model simulations.

Wednesday, November 22, 2023

2023-2024 Winter Outlook - El Nino with a twist !

Welcome back for year 20 and Happy Thanksgiving everyone !This November has featured some inviting, crisp cold air and a few dustings of snow which I hope has elevated everyone's anticipation for the upcoming winter. While we haven't managed to mimic the snowvember 2018 performance and we likely never will in my lifetime, New England has been ground zero for cold air this month and I am hopeful this serves as one of those atmospheric "tells". More on that later. For me, it's always just good to be back doing this for another season, skiing the mountain obviously but also hopefully providing some helpful intel as to the snowfall situation in the MRV. 

El Nino announces a 2023-24 world tour ! 

2023-2024 brings a significant El Nino back as a headlining act. It is easily the most dominant player on the playing field and has been flirting with Super Nino status this fall. More on that in the next paragraph. This year's ENSO (El Nino) is throwing a knuckle ball at us this year and I am going to use that adjective to honor former Red Sox pitcher Tim Wakefield who passed away way too young early last month. So why is this pitch a little harder to pick up ? The Pacific Decadal Oscillation's (PDO) warm phase is often coupled with El Nino and without looking especially close, I was hopeful that the 4-year streak of negative or cool phase PDO's would abruptly end. Though the PDO has weakened in the past month, it remains negative putting the Pacific Ocean in a counter-intuitive state going into the winter. After an initial sense of dread, I started researching winter's with this occurrence and to my surprise, we've seen a few in the last 75 years and almost all of them, incredibly, have had very good results.  


 

ENSO Specifics 

Let's discuss the El Nino situation first. The anticipation of this ENSO switch has been an ad-nauseum topic going back to the end of last winter. In this case, forecasts have been largely accurate, the critical regions of the equatorial Pacific Ocean have warmed to nearly 2 degrees C above average which nearly places this ENSO in what I like to call "Super Nino" status. By way of comparison, this El Nino remains a little weaker than the last two big ones. The horror show of 2015-16 was 0.8 C warmer, measured in temperature and the decent snowfalll winter of '97-98 El Nino was half a degree warmer. Though I have a general affinity for El Nino especially for the east coast storms they tend to produce, this one is coming in a bit too hot for my liking. I would prefer to see the equatorial regions closer to 1 degree C above average since the adverse impacts of the stronger ones have often included month-plus stretches of super mild weather. More generally El Nino has a propensity to weaken the onslaught of arctic air on northern latitudes of North America. We've seen this anyway thanks to the impacts of climate change so there's certainly some cause for concern. To reiterate, the benefit of El Nino has to do with storminess and specifically the type of storms. The southern branch of the jet stream is energized and is capable of producing juicy east coast storms infused with both Gulf of Mexico and Atlantic Ocean moisture. I should mention that the inland runner problem, a seemingly invariable fixture of the recent -PDO / La Nino winters during the last World Cup cycle are not nearly as prevalent during El Nino. I am sure we will manage to drum up a few of those because we like to do that in Vermont, but the chances of going a month or more without one is higher than usual. 

The PDO knuckler 

So now lets move the discussion back to the PDO because as I mentioned, we've been dealing with a sea surface temperature configuration in the Pacific which is making it very difficult to sustain cold in eastern North America. No winter was that more evident than the last which saw a varying iteration of the same story with cold weather confined to the west and western ski areas while the east coat was fending off one onslaught of mild weather after another. Since the epic winter of 2018-19 which included that epic Snowvember, the PDO has been showing us one negative result after another. It's a much worse issue for snow lovers across southern New England and points south, but even at 43 N, it's been tiring playing defense against mild air week after week. I've gone over the warm phase / cool phase PDO state a few times so I'll provide a link here to a more academic definition and move on.  

Can El Nino finally break the cool or negative phase of the PDO ? It hasn't yet ! There's finally been some evidence that the index is neutralizing at least anecdotally looking at this animation. 

SST 2-week animation !

A positive phase consists of the horseshoe of relative warmth in Pacific Ocean SST's that, across the north, follows the outline of the west coat of North America all the way to Alaska. This has the benefit of weakening the mid-lattitude latitude potency of the Pacific jet stream and encourage a more favorable positive PNA structure to the jet configuration. Having not gotten to that positive or warm phase of the PDO yet, I would be inclined to believe that this year's ENSO will be of that counterintuitive variety I mentioned above. 

My initial reaction to these developments wasn't positive, but upon further review the data appears quite encouraging. Yes, I have the cool/negative PDO fatigue but as former NBA player Rasheed Wallace once famously told a referee - "ball don't lie!". The cool/negative phase PDO is a problem for areas farther south during an ENSO but there are several instances over the last 75 years where we've been graced with this combination (ENSO/cool phase PDO) and almost all of them have been good interior New England snow years and a few of them have been the cooler version of El Nino. Here is the list which includes a surprising basket of really good years and only one bad one (1994-1995). 1972-73 might be the best comparison and it was infamous because of Philadephia which only recorded a trace of snow for the entire season. Vermont in contrast, has a terrific winter ! 2006-2007 is another really good looking similar year (not on the list because Nino was a little weaker) which had a horrible start,  but produced 7 amazing weeks beginning in the latter half of January. Interestingly, El Nino years featuring the warm phase PDO have been memorable for the I95 corridor, but have featured very mixed results in Vermont and the horror show that was 2015-16. 1957-58 and 2015-16 were two of the worst winters in the history of MRG operations and both had the typical strong ENSO/+PDO distinction. 


 

Snow/Ice expansion

Nothing extraordinary regarding the buildup of snow and ice in the northern hemisphere this autumn. The southern hemisphere made some news this summer for setting records for low sea ice in the antarctic region. The buildup of ice in the arctic is running well below what it would 50 years ago but appears relatively healthy relative to the last 10 years. One can play around with this interactive link to validate my assessment if you so choose. 

Interactive Sea Ice Graph  

Snowcover across the northern hemisphere appears very normal, chiming in at an 18.73 millions of square km for October which is slightly above the last two Octobers, but short of the big numbers we saw for several years prior to that. This number is well within a normal range however so the data can't provide many clues moving forward. 

Additional clues ? 

So while fretting about the strength of El Nino, I've also been watching closely to see if the atmosphere might be tipping its hand in another way and there are encouraging signs here as well. No longer has the west been hoarding the cold ! The recent World Cup cycle of cool phase PDO has left the east coast and New England specifically as the warmest spot relative to average in more months than I care to remember. This recent October was another example, but the recent summer finished magnificently with one of the best weather months in recent memory - August. We were the cool spot then and once again in November are likely to be one of the coolest locations in North America, a clear break from recent trends and a reminder that things like this actually do happen. I am also really encouraged to see the relative warmth in the Atlantic Ocean near the New England coastline subside. There is plenty of warmth in the Atlantic Ocean, don't get me wrong, and the oceans are making news for their warmth and will continue to do so, but at least this warmth is not, at the moment concentrated near us. This would certainly be a change from recent winters. 

 



Blog content moves from "X" to "Threads" 

Indeed, I've decided to move all the blog related content from Twitter/X over to Threads the offshoot of Facebook/Instagram. The Twitter account will remain active and alive with some weather stuff, news, music and last but certainly not least, a complaint machine for New York Mets baseball. The blog related stuff moves to Threads with the handle "singlechairwx" and the talk will be confined to weather and skiing in the MRV. Followers of the blog are fully encouraged to follow me on Threads, but I've considered it a mission to make the blog and information related to the blog available outside the social media ecosystem and that mission continues. All of the latest "threads" will be available to see on top of the blog. I'll avoid a discussion about certain reasons for moving content off "X" , but aside from those, I was encountering issues getting the feed to load automatically on the blog. Add to that were the randos hitting me up on the latest Crypto scam or other randos hitting me up for, well..... nevermind, but you get the point. Either way, I was always pretty impressed with how the Vermont weather and skiing community remained insulated from the toxicity that surrounds so hopefully we can build that up again on "Threads".

The Solar Eclipse on April 8, 2024

What would a seasonal outlook be unless I tried to forecast the weather almost 5 months from now. I can't obviously, but still excited about the solar eclipse next year. I am also here to report that many of the El Nino springs I've experienced have featured early spring months that are sunnier and warm relative to average. It makes sense if you assume weather might be confined to the southern part of the US eliminating the cloudiness across the north. I've never conducted any real study so this is purely anecdotal and I might add that I don't want the south to hog all the weather this winter.   

Summarized 2023-2024 winter outlook 

I've tempered my warm expectations for the winter because of the research suggesting it seems unlikely to go entirely that way. Still however, we have a big El Nino and those usually are milder than average as a whole. The last several El Nino's have been mild because of a 3-4 week horrific torch and I feel this to be the likeliest outcome. The '06-'07 and 2015-'16 El Nino both featured very warm December's and this appears a bit less likely this time looking at the current weather pattern going forward. The Rasheed Wallace "ball don't lie" says it will be snowy and I am going with it. The reluctance of the PDO to turn completely positive should help the interior at the expense of the coast and bring some really nice storms to Vermont and fewer inland runners. Temperatures as a whole will be above average by 1-2 degrees but snowfall will also be little above average depending on how it's measured. Admittedly, I remember taking a similar stance prior to the 2015-16 El Nino and face-planted off a covered bridge, but lets try this again since we have a decent sample size of data backing us. Hope to see you all on the hill and again, hope everyone enjoys their holiday.