Friday, February 22, 2019

Sunday's thaw looks pretty minimal but still a little wet while next week appears colder but also drier

Conditions across the high country have been a bit changeable over the last few days and this will be the story for the weekend as well. Bits and pieces of the intense area of cold out west have effectively won control of Vermont at times but at other times given way to the occasional mild intrusion. Given the power of this especially negative PNA regime, the snow across the northern Vermont high country as held up pretty well. I expect that it will also hold up ok on Sunday in spite of the less than ideal weather situation.

The first half of the weekend is the tranquil half. Some sunshine, good visibility and limited wind will be the featured conditions and temperatures should get pretty close to the freezing mark during the afternoon and may exceed it for a few hours at at the base. Clouds are expected to overspread the region late Saturday evening and the precipitation from our advancing storm will arrive within a few hours of dawn Sunday. Meteorologically speaking, the Sunday weather system is one of the strongest to impact Vermont this month but the storm will be somewhat of spent force before reaching the east coast with the worst impacts being felt across the Upper Midwest and western Great Lakes. The main area of low pressure is again going to take a god-awful path into Ontario and central Quebec which can open the door for a snow-eating torch across much of New England. It appears pretty apparent, based on the latest data, that a new area of low pressure, expected to form late Sunday along the New England coast, will effectively tie off the northward advancement of mild air. The result will thus be a period of mainly sleet early Sunday followed by freezing rain and then a short period of cold rain. No big melt off but no big powder either.

The period between Sunday night and Monday night still appears to be a good one for terrain enhanced snow showers as cold air slowly builds back into the region. For winter standards, it appears to be a particularly deep area of potential instability and well-aligned winds. This doesn't guarantee much in these type of events and my experience suggests that the best snow will be from Stowe northward given the wind direction. Still, continuous snow showers, some of which could contain some briefly heavy snow should be able to bring a few inches of recovery powder back to Mad River Glen by Tuesday morning. Right now I would be willing to call it 3-6 but again, the best chance for that "6" will be farther north.

Escape from the negative PNA not only appears on track toward the end of the month but it appears ahead of schedule. Temperatures appear colder in the Tuesday to first weekend of March time frame and will likely stay below the freezing mark throughout that time frame. The only issue with that is the drier outlook associated with that change. The potential midweek storm next week appears farther south on most of the simulations though the possibility for a Wednesday/Thursday snowfall is not entirely eliminated. What does look a bit more promising is the potential for some east coast action around the time frame of March 1st and 2nd (a Friday and a Saturday). The potential east coast storm would involve the merging of a clipper system and some southern energy. I wouldn't call a big event particularly likely right now but that might be our best hope over the next 10 days.

The colder regime, fueled by the Alaskan ridge is expected to win the day through around March 6-7 and then there are hints of another pattern realignment and some milder temperatures by around March 10th.

No comments: