Monday, December 21, 2015

Our long awaited pattern change is finally in sight !!

Happy solstice (officially Tuesday Dec 22 this year). With the darkest day of the year comes brighter news. Though some incredibly persistent warmth will continue to cover eastern North America through the Christmas holiday,  it should finally end around the New Year and winter will finally make an appearance. I don't expect a sustained period of extreme cold but with the AO leveling out and even going slightly negative combined with the disintegration of the evil empire in the Pacific, the snow should finally start to accumulate and we will move closer to an opening at MRG. There are even more encouraging signs within this new pattern that should serve the region well and that will get discussed a bit at the end.

In the meantime we still have to contend with the last 10 or so days of this near tropical weather pattern. After a bit of light rain Wednesday night, Vermont will enjoy what might very well the warmest Christmas Eve anyone of us will remember. Temps in the 60's, no snow on the ground and maybe even a thunderstorm to go along with the egg nog late in the evening (though that's probably a slim chance). Absolutely insane ! No point worrying about damage control with nothing to damage. With no base on the mountain, might as well enjoy the warmth rather than get insulted by it.

The Christmas to New Years stretch will not be quite as mild but nonetheless mostly unproductive. It will be an active stretch of weather with the first storm bringing rain and ice to the region Saturday night. As mentioned in the prior post, arctic air will make a rare December 2015 appearance as it presses southward against the large enveloping east ridge. Vermont will get a taste of this chill later Sunday into Monday the 28th as temperatures fall into the teens and remain mostly below freezing Monday. The cold will never attain a firm grip on the region and will be mostly scoured out of the region by the next, even stronger weather system on Tuesday the 29th. Though we might see some additional sleet or ice, we are unlikely to see any snow out of this system. 2015 will finish the year on the mild side with readings generally above freezing during the day and only a few degrees below freezing during the night.

With the new year comes a new pattern finally. Though not an overwhelmingly cold pattern,  the playing field will be leveled if not tilted somewhat in our favor. Our biggest asset will be the development of a large ridge in the jet stream across western North America which will boost the PNA index well into positive territory. This will be the mechanism which should essentially keep temperatures below the freezing mark for an extended period of time after the new year. Without the overwhelming presence of the polar jet or a polar vortex, activity in the southern branch of the jet stream should also persist. This should keep the door very open for a big east coast storm and I expect at least one between the first and 10th of January 2016.

Enjoy the mild weather and don't let it damage your spirit. Better times are finally in sight.

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