Sunday Evening Storm Update: Snowfall In Vermont Will Be Highly Variable

The latest National Weather Service forecast snow map
issued Sunday afternoon shows an incredible range
in expected snow fall. Parts of the Northeast Kingdom
could get as little as two inches of new snow. Some of the
east slopes and summits of the southern Green 
Mountains could get as much as 18 inches.

 It actually got nice this afternoon as skies remained sunny, winds were light and temperatures rose from frigid morning lows in the teens below zero to the low 20s above. I was outdoors for awhile and it was actually pleasant. 

Monday, as we have been advertising, will not be pleasant. 

It really is a dynamic storm headed this way, but the effects it will have on Vermont will be extremely variable. When all is said and done, you'll drive some pretty short distances between spots that get just a few inches of snow and areas that get more than a foot. 

The east and southeast winds with this storm are stronger than usual for a storm coming up the coast. This creates "shadows" on the west slopes of mountains.  The moisture-laden winds hits the east slopes of those mountains, forcing the air to rise, which in turn dumps tons of snow on those areas.

Once those strong winds pass the crest of the mountains, the air flows downhill on the western flank of the mountains. Sinking air dries and warms the air, so much less snow falls on the western slopes. 

I wouldn't be surprised if parts of the Northeast Kingdom, in the "shadow" of the White Mountains of Nw Hampshire, and the immediate west slopes of some of the Green Mountains, especially central and south, only get two or three inches of snow. 

Those downslope winds on the western slopes are still forecast to gain momentum as they come downhill, so damaging, sporadic and local wind gusts on the western slopes could be damaging for a time in the morning to perhaps early afternoon. With snow laden trees, the wind could knock those trees and power lines down. 

Peak winds in the downslope areas are forecast to reach as high as 55 mph. I wouldn't be surprised if they go locally higher. 

To me at least, the northern Champlain Valley is a wild card as far as snow amounts go.  Especially once you get north of Colchester, the Green Mountains are pretty far to the east. I have to wonder if that dried up atmosphere on the immediate slopes of the Greens would begin to recover and give places like Milton, Georgia, St. Albans an Alburgh an opportunity to get a little extra snow.

At this point, the National Weather Service in Burlington is forecasting about five inches of snow for northern Champlain Valley and that seems reasonable to me. 

As we mentioned this morning, a punch of dry air will come in to shut off the snow by late morning. The afternoon will feature just clouds, and spits of snow, or more likely a few ice pellets, sprinkles, drizzle or freezing drizzle. Many areas will briefly poke above freezing during the afternoon.

That will be short lived as a cold front brings a burst of snow to end the day. Not much more snow will fall Monday night, but the northern mountains should pick up a few inches. The western slopes of the northern Green will partly make up for the lack of snow during the initial phase of the storm Monday morning.

The temperature yo-yo continues. We had the subzero weather, the warm phase of Monday's storm will get some us above freezing and by Monday night, we're facing single digit temperatures and subzero wind chills. 

ELSEWHERE

I hope you weren't flying anywhere. Between staff shortages from people calling in sick with Covid and the winter storm, at least 2,700 flights had been canceled as of mid-afternoon today and that number was spiraling upward. 

Florida had its first EF-2 strength tornado since 2016 this morning as the storm's cold front blustered through the state. That front is now offshore of the east coast of Florida, so the threat of severe weather is over for the Sunshine State. However, strong west winds behind the storm are causing some coastal flooding on the west coast of Florida this evening. 

Travel is pretty much impossible in much of the south today amid freezing rain and snow. Video on social media showed trees and wires collapsing under a heavy weight of ice and gusty winds across parts of South Carolina. Other areas have heavy snow.