Think Snow, Tweet Snow !!!

Tuesday, January 20, 2009

Storm track for Saturday shifts north, active pattern starts January 25

The base at Mad River Glen has made a slow but steady recovery since the great post Christmas thaw. If we use the Mt Mansfield snow stick as a reference then our base is slightly above average. The base has been aided by temperatures that are running almost 5 degrees below average for the month of January and with more cold on the way late this weekend many areas of New England will see the coldest month of the decade after seeing some of the coldest temps of the decade just days ago.

Northward shift in Saturday's storm track lowers snowfall expectations

Snowfall for the balance of the "work" week will be held to a minimum. Flurries and a few snow showers can be expected across the northern half of Vermont on Thursday thanks to a disturbance that I should forget to mention. Temps, as promised, will climb back into a comfortable territory although I would enjoy this while it lasts because it won't. The system we have been keeping our eye on in the shorter term is a clipper system that will mark the charge of the next round of biting cold. The latest indications are that the best conveyor of moisture will be situated farther north into Quebec. I had hoped would get lucky and get 5-10 inches of low density fluff with this sucker but expectations of now should be appropriately lowered to the 2-4 inch range. Most of this minimal accumulation will fall prior to first tracks time Saturday and when the snow ends we could see temperatures inch toward the freezing mark by early afternoon. During the evening, winds will shift into the northwest and temperatures will fall dramatically and be well below zero with -20 wind chills on Sunday.

Active week Jan 25-31
The week beginning January 25 has lots of promise but the details remain difficult to resolve. We will at this point replace the ridge in the interior west with a trough. This can be quite detrimental and can cause a thaw or a round of rain even as far north as interior New England. As the ridge is developing in the west downstream blocking in Greenland and across the extreme high latitude locations will strengthen. It is a stretch to refer to it as "blocking" but it is enough to counter-balance the impact of the strong western trough and will help us avert disaster in the last days of January. In terms of actual weather, the result of all this will be several west to east moving storm systems capable of picking up Gulf or Atlantic moisture as they progress eastward. We will also see a strong south to north contrast in temperatures and this will mean lots of overrunning and possibly lots of snow for parts of New England. The term "overrunning" and New England have always fit well together in case I haven't mentioned it. My guess right now is for two noteworthy weather systems next week with questions persisting regarding where the best zone of snowfall sets up. Sleet or freezing rain is not out of the question but at this time that possibility remains at the edge of the spectrum.

As we move into the early days of February, the continued presence of the consolidated jet stream in the Pacific and a strong trough across the interior west could be enough to induce an east coast rain or ice event. The weather pattern is exhibiting some similarities to the one in late December which first produced an epic powder fest but then gave way to a thaw. We our however later in the season when surface thermal forces such as the the colder and ice covered Great Lakes provide less of a northward magnetic pull.

2 comments:

Jim Jenkins said...

My birthday is the 31st-I've asked for a fresh foot+! Keep us posted, Josh.

TJR said...

Thanks Josh.
It seems we always get a warm spell before Christmas and again in early February, what’s with that?

Hopefully not this year.


TJ