Thursday, February 23, 2023

A snowy, wintry next 6 days of weather highlighted by storm potential as February transitions to March

Heard a few folks on the MRG single line saying they were a bit underwhelmed with snowfall totals Wednesday night and I don't disagree. Even late last night I thought we had a decent chance to outperform expectations, but drier air appeared to weaken the area of overrunning snow just a little, though the 7-8 inches that fell skied very nicely. And our storm continues through Thursday afternoon and into the evening and overnight. There is a weak and pesky warm layer that is expected to linger over central Vermont just enough to allow the light snow to mix with some sleet for a time this evening. After midnight however, shallow boundary layer instability combined a very favaorable northwest flow off Lake Champlain will combine to produce a few hours of decent snowfall, especially over the high country. If we can manage to avoid any sleet, I'd be willing to predict another 3-6 inches by first chair Friday, but I can't assume the best and am inclined to anticipate a more conservative 2-4. Arctic air should really dry it out by late morning with blustery conditions, temperatures near 10 and increasing amounts of blue sky. Actually, I've really come to appreciate those type of days after some fresh snow cover, especially since they've been in short supply this year. 

Skies should stay clear just long enough to allow temperatures to drop as low as -10  n a few spots Saturday morning and to allow some sunshine to warm readings back into the teens Saturday afternoon, but a lot of weather is being aimed in our direction over the next week and clouds are expected to return later in the day Saturday. It doesn't seem like we can spin up a significant snow producing system this weekend, but some light snow is possible Saturday evening yielding little accumulation and then more light snow is probably Sunday yielding potentially a small accumulation. Sunday's snow comes from a disturbance diving southward out of Canada and my optimistic ski goggles tell me the mountain could score a few fluffy inches from that, some of which might fall after the ski day. 

The more interesting period weather-wise continues to be the time frame beginning Monday night (Feb 27) and persisting through Wednesday March 1st. A downstream block in the jets stream will help push this storm southward while a lingering jet stream ridge in the southeast U.S. pushes this system northward effectively squeezing it through our open window. As I expected, none of the models are threatening us with the R word anymore and the concern really just involves our proximity to the deeper plumes of moisture this storm is sure to produce. Initially this weather system will approach us as a very wound up and mature cylcone from the Great Lakes region, but the storm will transition some of its energy to the southern New England coastline by early Tuesday while the matured and eventually decaying system slowly approaches northern New England. There's a big ceiling with potential snowfall expectations less because the strength of this storm but rather the nature of this slow-moving weather system operating underneath the downstream blocking. We still could miss everything or most of everything, but the established consensus for now has us on the northern end of some decent snowfall. Hopefully it evolves into the one we've been waiting for. 

The weather pattern has promise moving forward into March but there's a period bound roughly by Friday, March 3 and ending around March 7th that has moved toward the milder side, mainly because the core of arctic chill shifts westward and west of the Hudson Bay allowing more milder spring-like weather to move northward (occasionally reaching VT). The blocking -NAO structure remains and will have to work hard to suppress more storminess that is expected to approach for the full weekend in March. The "R" word is more likely with this event though I would favor a combination of precipitation types as a very initial guess. Ensembles really work to tame the Pacific beginning March 8th and when combined with high latitude blocking that is expected to remain in place (at least some), winter remains an unfinished work, at least around these parts. Expect more talk of storms as we proceed toward the 30th anniversary of the best winter storm to impact me !


1 comment:

Unknown said...

Hey Josh,
What's your take so far on Tuesday's storm?
Thinking of coming up...
Steve