Latest on the MLK storm and a cold, wintry finish to January

Bitterly cold temperatures were a little delayed Friday morning but not denied with readings plunging rapidly into the single numbers across northern Vermont Friday evening. Expect temperatures to remain mostly below zero Saturday across the northern Vermont high country with strong winds (especially at the summits) continuing through early afternoon before subsiding by the evening. A much calmer day can be expected Sunday with sunshine warming temperatures into the teens by the afternoon. If you appreciate some of the big visibility winter days like I do, then Sunday comes highly recommended. 

The latest on the MLK storm is as follows. The storm is a really nice base-building type event but I would not expect epic snowfall amounts. It's close but, it's just not that type of storm. The already very mature cyclone will move from the Gulf Coast to the North Carolina Piedmont on Sunday and subsequently move northward while fighting to establish a coastline presence. The elongated low pressure center will pass pretty far west (as far as nor'easter's go), perhaps even through western Mass and up over the Upper Connecticut River Valley.  Followers of the blog (and of weather in general) know that this is less than optimal though not disastrous. The MRV is well positioned to get a deep plume of moisture early Monday but also positioned to get challenged with warmer marine air along with a dry slot. Expect snow to begin and become quite heavy for a time early Monday (lets give a start time of 6 am) with several inches of accumulation before precipitation mixes with and possibly even changes to sleet. If the track of the storm follows or even shifts west of this trajectory, the push of low level warmth is powerful enough to change the precip type to rain very briefly though I am of the opinion that this happens in the form of drizzle and during the period where the dry slot has overtaken much of northern Vermont. The snow and some sleet that arrives on Monday will be of the very dense Atlantic variety. It won't be glop or sierra cement but any mixing with sleet will very much weigh it down. I really enjoy reading Scott Braaten's analysis especially when he talks about dendrite growth and how it relates to snow consistency. I think he would agree with my assessment here but check him out on facebook for confirmation. After a several hour lull, the snow should return during the evening and continue at a lighter rate but of a much fluffier consistency into early Tuesday.  

I remain a bit uncertain about the sleet mixing (midday Monday) as of Friday evening. A couple of runs of the high resolution model are aggressively blasting milder air into Vermont but these simulations have their limitations out past 48 hours. Both major global models continue to suggest a primarily snow event although it is close. I point this out because it is of material consequence when it comes to predicting snowfall amounts. Sleet is highly dense in nature, snowfall is not and sleet can weigh down already fallen snow. With all of this in mind, I am sticking with the 8-16 prediction for the time being with 4-10 very dense inches falling early Monday and 4-6 fluffier inches falling Monday evening, night and into Tuesday. Accumulations will be elevation sensitive, especially during our 2nd dose of snowfall.

Expect fairly typical January-like temperatures Tuesday into Wednesday with a sharp and very intense surge of arctic chill approaching Wednesday evening. We have another shot at a few inches of snow on Wednesday as the arctic boundary approaches and some additional terrain enhanced powder is possible Thursday but the this surge of low level cold is powerful enough to stabilize the low level environment pretty quickly by late in the day. Friday into next Saturday looks like a freezer across all of New England, Vermont especially with plenty of sub-zero readings during the overnights and readings struggling into the single numbers during the day. 

The outlook continues to look quite cold, especially during the period beginning Thursday January 20th and persisting through at least January 28th or so. We can expect to hear talk of the polar vortex which should be in the vicinity of Vermont at least once during this period. Such a pattern can suppress storms to the south but there are signs of both clippers and even a more organized coastal system in between arctic shots of cold next weekend. It's January and it will certainly feel like it for the duration of the month.