Wednesday, February 1, 2023

The Arctic Cold Gathers, Then Weather Whiplash In Vermont

Latest wind chill forecast map from the National Weather
Service office in South Burlington, valid 7 a.m. Saturday.
Most of us are in the upper 30s to mid 40s below
on the wind chill scale. 
We got our first taste of true winter cold this morning, with much of Vermont going below zero.

Burlington got to minus 2.  This was the fourth latest first zero of any winter I'm aware of.  Meanwhile, Island Pond, Vermont and Saranac Lake, New York dipped to 20 below. Lake Eden, Vermont was close behind at 18 below.  

We'll see a warmup of sorts today and tomorrow ahead of the long-anticipated Arctic blast, but it won't be all that balmy. Today will get into the low to mid 20s.

Thursday could hit the low 30s in warmer valleys. But gusty south winds will make it feel colder. Then we get into the nastiness: 

Thursday Night: During the first half of the night, the cold front arrives, probably accompanied by a band of snow squalls. Those will create quick drops in visibility and danger on the roads amid brief heavy snow and blowing snow. 

Overall accumulations won't amount to much, perhaps an inch or two, but that's not the real story, of course Temperatures will rapidly crash, and probably be below zero by dawn across much of Vermont, central and north. 

Wind chills will have drop into the 30s below overnight and before dawn. We do have that wind chill watch for all of Vermont and surrounding areas from late night Thursday through Saturday. 

Friday: A real ugly day for sure. If you greet the dawn Friday at below zero, there's a good chance actual temperatures won't get above zero all day.  The warmest anyone in Vermont will get will be close to 10 in the "warmest" southern Vermont valleys.

North winds will continue blasting all day at around 20 mph with higher gusts. Wind chills will be in the upper 30s and 40s below all day. This is truly dangerous weather, especially since we're not accustomed to it. 

If you must go out, be sure to keep skin covered. Make sure your car is ready with a good battery and a full tank of gas. And keep some extra blankets and other warm clothes in the car in case you get stuck out there. Also, how's the fuel tank in your house? Full enough? Check it now. 

Lake Champlain will look interesting amid the frigid temperatures and strong winds. It's still largely ice-free, thanks to the warm winter we've had until now. You'll see lots of wind blown steam, and perhaps some whirls or funnel clouds out there.  Lake effect snow will probably fall southeast of the lake, but accumulations will be light. 

Friday night: That, of course, is when we bottom out as Arctic high pressure noses, aided by the Polar Vortex, which by then will have swooped into eastern Quebec and touching the northern tip of Maine. 

Although winds will diminish, they won't entirely die out, which means two things. On the bad side, wind chills will still be in the basement, staying in the 30s and 40s below. On the good side, the winds will keep the air mixed in some locations, so the actual temperature won't go as low as it could if everyone had calm winds. 

That's not saying much. Temperatures through most of Vermont will pretty uniformly be within a few degrees of 20 below.  Probably mid and upper teens below in the Champlain Valley and warmer valleys of southern Vermont, and mid 20s below in the colder spots. Deeper northern valleys could be protected from the wind. I wouldn't be at all surprised to find some 30s below actual temperatures in Vermont by Saturday morning. 

Climatology Comparison:  It certainly is possible for even Burlington reach 20 below. If it does, it will be the first time it's gotten that cold since January 7, 2018

This will also probably be the coldest February temperature since February 24, 2015, when it was 19 below in Burlington. In the off chance it gets to 20 below in Burlington, it will be the first time it's gotten that cold in February since an especially intense cold wave on February 7, 1993 brought Burlington down to 27 below.

As intense as this Arctic blast is, it certainly won't be the coldest February readings on record. In Burlington, that honor goes to a 30 below temperature on February 12, 1979.  Statewide, the coldest on record in February is 46 below in East Barnet in 1943

Saturday: After that horrifically cold start, temperatures will only slowly warm under a fair amount of sunshine. North winds will continue to make for a terrible wind chill. Most places in northern Vermont won't even get above zero. But at least winds will temporarily diminish in the afternoon. 

Saturday night: Here's where weather whiplash starts to get us. I told you this would be a brief Arctic smash. Temperatures wills start to crash at and just after sunset, especially east of the Green Mountains. But before they get too cold, they'll level off as the core of the cold air zips off to the northeast. Plus, south winds will start to blow. 

Here's something to warm your heart. After our Arctic
blast Friday and Saturday, long range forecasts call
for warmer than normal weather in the eastern U.S.,
including in Vermont, next week. 

Temperatures will bottom out during the first half of the night in the teens below zero in much of eastern Vermont and single digits below west.

Temperatures in many places, especially the Champlain Valley, will rise overnight and during the wee hours of the morning. It'll actually get pretty windy in the Champlain Valley overnight, so blowing snow will become a problem. 

Sunday: Weather whiplash continues. We're dealing with a strong warm front and a strong cold front. Neither will have much moisture with them. .But what they lack in moisture they'll make up for with winds. 

The Champlain Valley will "warm up cold" as I like to say. Temperatures will rocket upward, but the stiff winds will make it feel colder. Pretty much everyone in Vermont will see some pretty good south breezes. By late afternoon expect highs to actually be at or a wee bit above normal.  That means highs in the 27 to 35 degree range. 

Sunday night: The one trouble with the approaching cold front will be the risk of more snow squalls Sunday evening, so we'll have to keep an eye on that. The "cold" air coming in behind the cold front won't be cold at all, so we should expect a normal winter on Monday. Highs in the 20s to near 30.

Beyond that, it could be 40 degrees by Tuesday. 


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