Tuesday, February 18, 2014

Some snow Wednesday but no avoiding the ice/rain Friday

Arctic cold is very slowly giving ground to milder pacific air, but this very gradual process has already resulted in a few inches of snow Tuesday. On Wednesday we will see an encore performance as a clipper system will gain some last minute steam along the southern New England coast. A week ago this looked like a "spring"day, now it's a powder day. Sort've a powder day I suppose, since snow will actually develop Wednesday afternoon and continue into part of the evening. Temperatures will be considerably milder than early in the week, approaching the freezing mark, but the day will feature snow, another 2-4 inches.

Thursday is still expected to be dry and the late February higher angled sunshine will go to work, sending readings above the freezing mark and likely softening the snow on a good part of the mountain. Lack of wind and great visibility will make it one of the more comfortable days this month. Temperatures will have a brief opportunity to duck under the freezing mark Thursday night ahead "odorous" storm system discussed in the previous update. A strengthening upper ridge across the eastern third of the U.S. will unfortunately guide this storm deep into Canada, ultimately stalling out east of the lower Hudson Bay. A surge of warmer temperatures will thus reach Vermont, but before it does, precipitation is expected to develop across the state and at MRG in the pre-dawn hours Friday morning. Temperatures cross sections make it appear that areas of the state, east of the Green Mountain spine, will see a several hour period of freezing rain Friday morning before precipitation goes to plain rain during the day. I think temperatures might creep into the low 40's briefly Friday but this will not be an extended thaw. The rain will end by Friday evening and temperatures will be back in the 20's Saturday morning.

We had discussed a possible storm over the weekend, an event which could have quickly erased the bad feelings of our Friday rain event. Unfortunately, models have taken a decisive turn against such an occurrence. There are a series of weak upper air impulses between Sunday and Monday which could provide some refreshment. Monday the 24th also looks potentially unstable enough for terrain induced snow showers. We can then look forward to another cold week to finish off the month of February, this thanks to a surging PNA index. Models have hinted at a coastal storm during the middle of the week but Vermont snow is being indicated to be the end result of clipper type systems (this could change). Temperatures, as mentioned will be chilly with high's in the teens and 20's most of the week and low temperatures in the single digits or below zero.

There is evidence of another temperature moderation at the very beginning of March, at least a brief one. If this occurs I think it will be short-lived and I believe more split flow in the jet stream will dominate the early part of the month. This means another round of active weather much like we have seen this month.

1 comment:

Unknown said...

Wunderground is calling for a lot of snow first week of march...too early yet to know?