Wednesday, February 21, 2024

Elevation sensitive snowfall Thursday night into early Friday and a mostly wintry weekend even though warm pattern looms

Across the entirety of the United States, February seems destined to finish as the warmest on record, powered largely by unprecedented warmth in the middle of the United States, especially the Dakotas, Minnesota, Wisconsin and Iowa. Hard to find silver linings in a month like this yet there are some, including increased amounts of sunshine and the lack of rainfall. Vermont has also not been at the center of the warmth and will probably avoid having the distinction of recording the warmest month ever. The statistical semantics aside, February of 2018 stands out  as my least favorite in a winter where we saw a lot a lot of early season snow and cold melt away, only to be replaced eventually by one of the most epic March's ever. We need another such March to bring this winter if we are to move this winter out of the "dud" category. 

One thing we have had is some wintry weekends and we get another one to finish off the month of February. We won't get a big storm to materialize this Friday, as expected, but clouds will replace the recent stretch of sunshine on Thursday and an extended period of light snow is expected Thursday night into Friday morning. Valley areas can expect the snow to be of a damp consistency and this is likely to extend to the base of MRG. Slightly colder temperatures are expected closer to the summit areas where the snow will be drier and should continue to fall through noon Friday. I expect 3-7 inches out of this 12 or so hour snowfall event with the range accounting for the elevation sensitivity of the event and the lingering uncertainty as to how much moisture can get pushed into northern New England more generally. I don't expect wind speed to be an issue on most of the mountain Friday, but the directionally speaking, prevailing southeast is typically the one of concern for the single chair. Winds will become northwesterly late Friday evening into Saturday and remain pretty strong bringing a brief period of very intense chill to northern Vermont. I would expect temperatures to remain below 10 on Saturday on most of the mountain with winds chills well below zero. One might additional snow from snow showers late Friday into early Saturday, but this cold appears undercutting in nature providing a stable boundary layer and putting a hard lid on convection. Though we are in the midst of a warm pattern to finish the month of February, Saturday will be one of the coldest skiable days of the season so prepare yourself accordingly. Weather conditions will be very different Sunday following a chilly near zero start to the day. Southwesterly winds will boost temperatures up to near 30 and indications are that we will receive some decent sunshine.

I can't speak much for next week if you like wintry weather. Were I to talk about weather in Alaska, I could write about both blizzards and extreme cold. The recent run of big -PDO winters have brought some decent chill to the 49th state and when they get cold often times we are not. Monday will see temperatures creep above the freezing mark but my concern is for Wednesday, Thursday or both when there is a risk of excessive temperatures and rainfall. 

In the longer range, there's been some talk about a Sudden Stratospheric Warming disrupting what appears right now to be a mild outlook for the month of March. The SSW occurring now has been linked to disruptions in the polar vortex in the troposphere capable of bringing large scale outbreaks of arctic air southward to mid latitude climates. The cutting edge research relating to this phenomenon has been very intriguing, but SSW events have not been reliably predictive because results have varied for each event. Basing the outlook exclusively on ensemble guidance continues to reveal a mild outlook for the first 10 or so days of March. This pattern is likely to breakdown regardless of the impacts of SSW after that, though its difficult to say if we will experience a full reemergence of winter and another big March 13-15th storm that has become tradition in recent winters.



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