Storm this weekend is no home run but looks better overall for natural snow in northern VT as pattern sets up to lock in cold weather for a few weeks

Using the Mt Mansfield snow stake as the official northern Vermont measuring stick, snowpack continues to run well below average as we enter the middle part of January. It's been mild in a relative sense as well, with temperatures about 5 degrees above average. So far though, its been 5 harmless degreese since temperatures across the northern Vermont high country have stayed below the freezing mark for the first 13 days of 2021. Over the next few days, we can expect some of that above freezing air to creep up the mountain side during the days but not by much and our attention will be fixed on the weather situation for Saturday which should bring our first substantial new snow since the New Years holiday. 

A very potent jet impulse is expected to dive southeastward out of the Canadian prairies and spin up quite a storm across the upper midwest Thursday into Friday. This storm will spin up and ultimately spin itself out, occluding and weakening as it turns east and then northeast. This process will carve out a beautiful trough across eastern North American setting the stage for our weekend weather situation. Just a little spark is all we need along the Atlantic Coast and a spark is what we are expected to get with a storm forming along the Delmarva and moving northeast and inland over southern New England. The speed at which this storm strengthens or bombs is the critical question at this point. A quicker strengthening might result in a bit more warm air and some mixed precipitation for us at the start but will yield better result at the finish with a foot or more of snow by midday Sunday. I am relying on the recent European run which shows some modest strengthening as the storm approaches Vermont but has yet to fully mature as a consolidated coastal system. Though changes are possible, this scenario would allow snow to begin before dawn and fall quite steadily for several hours into midday before drier air shuts off precipitation for a while later in the afternoon. A nice added bonus is what appears to now be a better setup for snow showers Saturday night into early Sunday winds shifting north of west allowing for a better moist feed from Lake Champlain which will already enhance some backlash moisture from the then departing storm. It's not easy set of details to sort through and some changes can be expected but a low end of 6 inches for Saturday and Sunday is what I am expecting. Temperatures will be closer to the freezing mark Saturday making the snow, especially at low elevations a little wetter, but whatever falls Saturday night and Sunday should be powdery but windblown. Temps for Sunday should remain in the 20's but the effect of the 20-30 mph winds will make it feel sub-zero. 

A weaker clipper system is expected to approach for MLK Monday but this system is expected to be weakening and much of the snowfall, what little there is, will be south and west of Vermont.  There are also some hints of some light snow in the middle of next week but it appears the storm to watch arrives late in the week. Interestingly, models are showing a more robust sub-tropical feed of moisture into this system after I declared the southern branch essentially dead in the last post. Ensembles are not so certain about all that but it does appear like we are in a pretty good firing line late next week for something. This would be followed by a chilly weekend on the 23rd and 24th with snow showers and snow flurries possible. 

On the general side of things I am a bit more encouraged with the pattern on the whole. Both ensembles are allowing a trickle of jet energy undercutting this mammoth ridge in the Pacific Ocean and this would weaken the potency and the +EPO index somewhat. The feature in the Pacific is one of the dominant forces on the globe but will connect with blocking in the Arctic and the continued presence of blocking in the Labrador Sea. I think this will have the effect of keeping cold weather in our grasp and perhaps allow for a several week stretch of sub-freezing temperatures beginning Sunday and extending into early February. The pattern appears active for the next week with aforementioned storm this weekend and another late next week. If the ensembles are correct by showing a broad area of unsettled weather out west and another trough out over the western Atlantic Ocean late in January, it would be a drier less active setup to finish the month but as I said, it looks quite cold and readings will likely finish the month below average across New England and more broadly across the eastern third of the United States.