Wednesday, April 5, 2023

Strange Vermont Weather, Cold Rains, Some Ice, Warm Spots, Thunder? Also, Midwest Storm Update

The National Weather Service in South Burlington is still
expecting patchy freezing rain in eastern Vermont and
northern New York today and tonight. Ares in red
could see up to a quarter inch of ice accumulation.
Orange and yellow areas will see lighter ice amounts.
UPDATE: 9:15  a.m.

The information I have further down about no overnight fatalities from tornadoes might be wrong.  I'm hearing unconfirmed (so far) of deaths overnight from a nighttime tornado in Missouri. I'll update as information comes in

I've edited that section of the post for now. 

PREVIOUS DISCUSSION

It's still looking like a rather nasty day in Vermont, especially this afternoon and evening, and tonight.  

The worst of it still looks to be in the north, and patches of freezing rain are still in the cards, mostly for areas along and east of the Green Mountains, and north of Route 4. 

The problem with the weather - and the forecast - is a complicated mess of warm and cold layers in the atmosphere, and winds coming from different directions, depending upon where you are and how high up you are.

Couple that with a blast of very wet air coming in from the Gulf of Mexico, and you have an unnecessarily complicated forecast.

Rain looks like it will move in from the west today and spread southward through Vermont this afternoon.  

Above about 5,000 feet in elevation or so, it will be springtime. Temperatures up there will rise into the 50s later today and tonight. The air at that level will be quite humid, and unstable. That sets the stage for some downpours and maybe some rumbles of thunder.

If we do get any thunder, it might sound a bit loud and strange, with each peal of thunder seeming to last a long time. That's because of an inversion. While it's warm up above us, it will be chilly down here near the surface.

Which explains the expected freezing rain in parts of Vermont.  It won't be an issue in the Champlain Valley, as winds will eventually shift into the southeast and keep temperatures pretty far above freezing.

East of the Green Mountains, relatively strong east to northeast winds will keep a supply of low elevation cold air streaming in from Quebec, despite the warm air high above.  Which explains the winter weather advisory for the eastern half of Vermont from Springfield north. 

It'll be patchy.  Some areas east of the Greens, protected from any mixing of the warm air above, could stay near 32 degrees from late this afternoon through much of the night tonight. That would accumulate ice on some surfaces. Especially on bridges overpasses, untreated back roads and sidewalks.

In a few isolated places, there might be enough freezing rain to accumulate on trees and power lines. I see the risk of isolated trouble in some patches in eastern Vermont north of White River Junction and in areas of the Northeast Kingdom. 

The south winds in western Vermont and east winds on the other side of the Green Mountains could get rather gusty at times, as well.  It should go over 30 mph at times, which will add to today's very raw character.

Rainfall (and melted ice) in Vermont will range from a half inch to perhaps over an inch in northern areas.  Forecasters don't think this will be enough to cause any real flooding but of course rivers will rise and there could be the usual field flooding and that type of issue.

The warm air high above us should finally mix down to the surface tomorrow, and temperatures will pop up quickly to the 50s and low 60s.

The storms cold front will be coming through tomorrow morning and early afternoon, so you'll probably see temperatures start to settle back downward from mid-afternoon on.

It still looks chilly and mostly dry Friday and Saturday, followed by a warming trend. I'm also still hopeful, judging from current forecasts, that next week will give us the first stretch of sustained, springtime weather. 

That would mean some highs in the 60s starting Monday or Tuesday, and we could eventually see our first 70 degree weather of the season. 

Daffodils, start your engines! 

MIDWEST STORMS

So far at least, the tornado and severe storm outbreak in the Midwest and South isn't nearly as bad as the one on Friday and Saturday. The trouble is, it ain't over. 

Several tornadoes did touch down in Iowa and western Illinois yesterday and last night, as expected. A tornado damaged some homes in at least one Iowa town, and several other areas in the state suffered hail damage to cars and houses. 

At first, I thought strong tornadoes failed to materialize in Arkansas and southern Missouri last night, which would bes a great thing.  But now I'm starting to hear of overnight tornadoes and deaths.  I'll keep looking for updates. 

However, severe thunderstorms were still firing away early this morning in Missouri and Illinois, a tornado watch was up for parts of Arkansas and Missouri, and forecasts call for a continued risk of tornadoes and severe storms today in the Ohio Valley and southern Great Lakes.

It still looks like the U.S. should mostly get a break from the severe weather after today. 


No comments:

Post a Comment