Sunday, March 21, 2010

Storm system to bring lots of moisture to Vermont but cold air is lacking

The cold air has been lacking for much of the month and the first 21 days has averaged an astounding 10 degrees above normal. The warmth has certainly corned up the snow quite nicely and the sun and relative lack of wind has made it pristine for outdoor activities. The snow, however is melting fast and a storm is very much needed in order to extend the winter season.

A storm is on the way and one which could have very much extended the season with the support of any cold air. Unfortunately, the cold more or less spent itself into bankruptcy across the western U.S. and will do little more than return temperatures to within the ballpark of normal. Meanwhile we have a storm system in the southern half of the U.S. which is spinning eastward and bringing rain to the 2010 snowbelt (Washington D.C.). This storm will grab Atlantic moisture as it moves northeast and spill it on much of Vermont and interior New England. Temperature profiles reveal a relatively warm lower 6000 feet of the troposphere and I would expect nothing more than rain below 2,500 feet. The rain will begin rather lightly on Monday but gain intensity by early Tuesday and should fall moderately and occasionally heavy through much of the morning. Above 2,500 feet we could see some snow mix in but temperatures should remain slightly above freezing so it will be a wet day for sure. As the storm continues to gain intensity and pull away to the northeast, colder weather will allow for more snow at the summits and for rain to change to snow at the base. This could lead to a few inches by Wednesday but the accumulations will be very wet at the base with only the summits having any chance for real powder. This is another storm which could have been a real winner for MRG but this winter has produced a litany of events where at least one puzzle piece always goes missing. In this case we have the moisture and we have a relatively favorable track but have little cold air. The event could bring 1-2 inches of rain to much of the Green Mountain spine which will damage the remaining bases to a degree but should not eliminate them entirely, particularly across the summits.

Snow showers and flurries will continue most of Wednesday and into Thursday although temperatures at the base should remain above freezing for the most part and any precipitation could be rain in the valleys. Late on Thursday, we should see a fairly good "punch" of cold air make a push into New England. This could bring a burst of snow to the mountain and finally bring temperatures universally below freezing on Friday. We will be watching a more organized storm system by the weekend but I don't think its impacts (rain or snow) will be felt until later on Sunday leaving the weekend free of any big precipitation. Temperatures will rebound to above freezing levels during the day and 20 degree readings at night.

The storm mentioned above does have some cold air as an ally but it track is a question mark and thus so is the precipitation type. At the very least we should see some terrain induced powder in the wake of whatever does evolve. It will mark a 3-4 day stretch of relative cold but it won't last as ridging in the central Pacific will again shift the storminess into the Western United States. It will thus likely be a rather mild end of March and early April and should set the region up for more spring conditions on whatever snow remains.

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