Thursday, February 14, 2008

A shift in expectations for Presidents Day

All the significant news relates to Monday's storm and until then there are no significant changes to report. An arctic boundary arrives during the middle of the day tomorrow and there is a weak weather system which is associated with this front that passes to the north. Mad River will not receive much in the way of moisture from this storm but snow showers late on Friday could dust the mountain with upwards of an inch or two. Very cold weather then arrives on northwest winds on Friday night. Winds will gradually diminish by later in the day Saturday but temperatures will struggle to get past zero on the mountain. Sunday will be more comfortable with temperatures reaching the 20's and light winds as sunshine in the morning yields to a high overcast.

President's Day

The news for Monday isn't good. As expected, the pattern will become highly amplified with a ridge in the jet stream stretching from the West Coast up through the Yukon and a developing trough in the middle of the country. Highly amplified patterns however are good for some and bad for others and although it is quite typical that the amplifications are favorable for east coast locations it isn't always the case. As for Monday, the ridge/trough axis will develop too far to the west and will thus force this once promising looking storm system to track from the Gulf of Mexico, west of the Appalachian Mountains and into the Great Lakes. In terms of actual weather, this translates to snow late on Sunday which quickly changes to sleet and then freezing rain and possibly rain for Monday. One thing that is rather surprising or alarming to me about this situation is that models are currently suggesting nothing in the way of coastal redevelopment. Northward progressing warm air is often nipped in the bud but such an occurrence and we did see indications of this a few days ago but much less so now. I am holding out hope because an unabated move toward milder temperatures in storm systems such as these is the exception rather than the norm. At the very least however, snow or ice is going to be difficult to avoid on Monday and the possibility of rain does exist.

Mid-Week
We are set up better for Tuesday as the low pressure center responsible for our potentially difficult situation on Monday strengthens over Quebec leaving a pool of much colder and unstable air in its wake across both New York and New England. We should see snow showers throughout the day as a result and although it is quite uncertain as to amounts, at least some accumulations are possible. A weak clipper system on Wednesday may also bring some additional lighter snows to northern Vermont and this will be followed by colder temperatures again on Thursday.

Long Range
The southeast ridge shows life again toward the weekend of the 23rd and 24th and will mean a northward push of mild temperatures. I know it doesn't sound thrilling but the warm advection associated with this push may mean some additional snow for Friday and it remains to be seen whether the mild weather will ever gain a foothold in Northern New England during the weekend. Toward the end of the month the ensembles are showing much more in the way of blocking at high latitudes and action in the mid-latitudes but its difficult at to pinpoint exactly when such a trend would translate into actual results for the mountain and it might not be until after the 24th.

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