Friday, December 23, 2011

Wintry through the 27th, rain and wet snow the 28th and warm weather for New Years

The ground is white, the trees are white thanks to the warm and wet weather that preceded our light snowfall and at least it looks a bit wintry out there. It will also stay wintry for the next few days with some single digit overnights and daytime temps in the 20's. The weather itself will remain dry through Christmas Day but a clipper system will bring its clouds to the region late Sunday and snow showers Sunday night into Monday. This clipper system is potent enough to temporarily carve a nice little trough along the northeast coast and there are some indications that instability as a result of this will allow for snow showers through much of Monday, enough for a terrain induced accumulation of a few inches.

The weather evolution next week appears a bit different than it has the last few days. Most of the changes are less than desirable, but Tuesday could be an interesting event although it if lives up to the tradition of December 2011 it will simply be another rain event. The changes involve southern branch Gulf of Mexico moisture and energy that will be grabbed by the collar by a faster moving clipper system. The result will be a significant precipitation producing weather system for the entire northeast beginning later Tuesday and none of this appeared likely even 36 hours ago. The cold which is expected to persist through Tuesday morning will erode very quickly and a fresh supply of cold will far removed from the weather picture. The southern energy however allows the storm to take a more southern track so temperatures should be close to freezing when the precipitation begins Tuesday evening. What appears most likely is period of both rain and snow, with precipitation beginning as a mixture before changing to rain then perhaps back to a heavy snow before ending midday Wednesday. With any weather system of this nature though, slight changes in the forecast variables could push the result in either direction. We could certainly use a surprise heavy snow. It is possible, if it does happen it could be of the "sierra cement" variety but us skiers know how desperately the Vermont high country needs a boost to the snowpack right now.

The less than desirable part of the forecast change will take place around New Years Day where it appears models are converging on yet another warm-up for the east coast. The mild push would begin Friday after semi-seasonable temperatures late Wednesday into Thursday. How fast this occurs remains uncertain but much above normal temperatures are now very likely in the New Years Eve to New Years Day time frame and with that will come the increased risk for more rain.

Beyond the first looks slightly more promising. Much will depend on the ability to break down the jet stream ridge in the central mid-latitude Pacific. There is not a lot of evidence of this as of yet and with that we will continue to struggle. That being said both ensembles indicate a ridge west/trough east jet stream configuration and such an outcome would still be better verses what the previous month has wrought.

1 comment:

Zach said...

Any chance New Years weekend could end up being snow instead of rain, or is it really looking bad right now?

Will the Adirondacks, Green Mountains and White Mountains at least be getting snow?