Wintry week to finish cold but some milder air has entered the forecast picture in the days leading up to Xmas

We endured the brief scare that our current December 17th storm might not deliver, but it has provided most of what was advertised and has restored some winter scenery to our beloved Vermont landscape. December will not go down as a particularly arctic month but the coldest weather of the month will nonetheless make its appearance, brought in by a potent jet impulse Wednesday evening. The disturbance will also bring snow showers and squalls to the northern Vermont high country just as the Wednesday ski day is winding down. The event will be short-lived, but a few good bursts of snow should provide 1-4 inches of wind driven snow to the high country around the MRV and possibly a bit more from Stowe northward to the Canadian border. The week is expected to finish on the dry but cold side with temperatures below zero Thursday and Friday morning in many places while afternoon readings are only in the single numbers Thursday and 15 on Friday.

Though Friday is expected to be pretty sunny across the region as a whole, the weekend will feature more clouds but with moderating temperatures. There are hints that the push of more milder air could be the catalyst for a period of light snow Saturday but that remains to be seen.  On Sunday we could see temperatures get pretty close to the freezing mark and likely exceed across some of the low lying areas.

The pattern for Christmas week now looks pretty well-defined. Though I wouldn't describe it as terrible, it certainly doesn't look particularly ideal. Much of the country's unsettled weather will be focused on California and the southern Rockies. The San Juan Mountains appear to be in line for a extra merry Christmas in 2019. The weather east of the Mississippi River appears quite mild. Interior New England will be one of the final hold outs this weekend we too can expect at least a day of milder temperatures on the mountain. Fortunately it only appears to be a 24-36 hour occurrence (Monday into Christmas eve) and one not accompanied by a significant amount of mixed precipitation or rain.

As the week progresses, there are continued signs that the ridge in the jet stream responsible for the milder weather will weaken and allow colder air to sink southward into interior New England. The question relates to what actual weather will accompany this push of colder weather on the 26th and 27th of the month. Some of the aforementioned storminess out west appears likely to push eastward toward the upper Midwest. Might some of this moisture end up falling as some late-week or weekend (December 28-29) snow in Vermont ? Quite possibly but the pattern does not support any notion of a big storm. Beyond that, there are continued signs of both storminess across the country and cold air focused on the western United States. In the preseason outlook, I highlighted the blob of ocean warmth in the eastern Pacific south of the Gulf of Alaska. For now it seems like a preferred location for a jet stream ridge which is not entirely ideal but again, we've seen worse patterns, especially around the holidays.