Tuesday, February 10, 2009

Rain makes it to MRG but changes to snow Friday; big east coast storm possible Feb 18

Too much mild air has made it deep into New England and we are not getting the help we need from the track of the storm on Thursday. It is a moist storm system which will track right over interior New England, normally not all that terrible but without any available cold we should prepare ourselves for rain. Some drizzle or freezing drizzle will commence as early as Wednesday morning and temperatures will climb above freezing as heavier precipitation arrives during the evening. About a half an inch of rain can be expected Wednesday night into early Thursday followed by a break in the precipitation while the atmosphere slowly cools from top to bottom. Finally, some snow will begin later Thursday which should continue into Friday thanks to the benefits of terrain enhancement. Terrain induced snow has been held to a minimum this year and the case can be made that the unstable layer of the lower atmosphere will not be enough to support a big accumulation but 2-4 inches by early Friday is a reasonable expectation all of which will be very much needed after the rain.

We have been waiting for February 12th in order to obtain more activity in the pattern and activity we will get. We will still have the benefit of the block stretching from eastern Canada to Greenland and this will ensure a winter-like regime. This and a relatively consolidated and active west to east jet stream will give us a few chances at storms. There are three in total worthy of mention and the question with all three is whether or not moisture can reach MRG's latitude. If the president's week part of the calendar is defined by the period beginning Friday the 13th and ending Sunday the 22nd then my prediction would be for 3 powder days and no rain. We will likely however miss 2 of the three storms mentioned and catch at least the healthy northern edge of one storm system.

Storm #1
Will start as a relatively disorganized area of moisture, much of which will stay well south of New England. By the weekend, low pressure will try and organize and move up the Ohio Valley and allow moisture in the Mid-Atlantic to make a northward push into New England. This system may not be strong enough and the precipitation shield may not be large enough for snow to make it deep into Vermont but we have seen this movie before and to say MRG has no chance for snowfall is both overly presumptuous and silly.

Storm # 2
Is a very interesting system which will carry with it a well developed area of low pressure even as it crosses into the Mississippi Valley around the time of Tuesday February 17th. This will mean big snow for a big part of the Midwest, an area of the country more accustomed to snowfall of much smaller amounts. As the storm moves into the Mid-Atlantic it will interact with the Atlantic Ocean and deepen rather quickly. A garden variety system with this storm track might fail to bring moisture into interior New England but this storm might do a bit better than garden variety. Since the weather system has such potential the range of outcomes stretches from dry weather to 20-plus inches of snow.

Storm # 3
Would arrive on the east coast just prior to or during the weekend of the 21st-22nd. It is a bit early to even characterize this one but it is another chance in a period where we will gladly accept as many chances as possible

In the event that we miss storm #3 or any of the other systems we can be assured of a continuous period of below freezing temperatures although nothing extreme. As I mentioned in the last post, the negative NAO is so strong that it will in effect block extreme arctic air from getting involved in the pattern. I don't think president's week skiers will complain but we will need the snowfall and all of it at least for now remains a question mark.

1 comment:

arthendrix said...

MRG Weather Update, 6PM Thurs. 2/12, snowing hard at the base, with 2 inches at the summit already. Prepare for a powder day tomorrow!