Hot, Nasty Not As Loud As Forecast Sums Up This Vermont Evening (Update)

Strong thunderstorm over Georgia, Vermont Wednesday.
So far at least, thunderstorms are not as widespread across
central and northern Vermont as originally expected

UPDATE 5 PM

Nothing like a band of clouds to squelch thunderstorms, and mercifully keep the heat from getting as bad as it could have.   

Just when peak heating hours were arriving in Vermont, a band of debris clouds from storms that were over the Great Lakes last evening moved over.

Those clouds kept a lid on temperatures through most of Vermont today, preventing readings from rising into the 90s as expected. Forecasters were expecting some of these clouds, but they were thicker and more persistent than many expected. 

The clouds also stabilized the atmosphere somewhat, which has so far prevented many storms from forming.

The exception is far southern Vermont where it was in the 90s at least in the valleys for a time.  The sun and heat did allow some storms to erupt there, and severe thunderstorm warnings lit up this afternoon along the length of Route 9 in far southern parts of the state.

It's still wicked humid and there are remaining spots of sun here and there, so we can't rule out some showers and thunderstorms developing this evening and overnight. Another pretty good one did form in Addison County earlier this afternoon, and there were some small, widely scattered downpours over the central and northern Green Mountains

If any storms do develop tonight, they have the potential for torrential downpours.

Tomorrow still is looking very warm and very humid, so more storms might spark off ahead of a cold front that will come through Saturday morning with a whoosh of refreshing air. 

PREVIOUS DISCUSSION 

If you liked yesterday's heat, humidity and storms in Vermont, you're going to love today. 

We're in the peak of our nasty little spell of weather, bringing on the heat, humidity and storms. 

Wednesday was really just the preview.  As mentioned a couple days ago, this is the worst heat wave of the year in Vermont.  

Temperatures are "cooler" than some of the hot spells in June, but the humidity is so much higher this time  that the air feels hotter than anything we experienced earlier this season.

For instance,  the temperature was 90 degrees at mid-afternoon in Burlington Wednesday, but the heat index was 96.  I worked outdoors for an hour Wednesday afternoon and that left me soaked head to toe in sweat and exhausted. I retreated to the air conditioning, at least until the thunderstorms erupted. 

In this regime of heat and humidity, it doesn't take much to set off a thunderstorm, and once they do start, they roar to life very quickly. Yesterday, updrafts in the eastern Adirondacks seem to kick off two cluster of storms, both of which developed explosively.

It always seems like the Middlebury area gets nailed and this time was no exception.  A severe thunderstorm caused a little  damage here and there in parts of Addison County and that storm remained pretty strong as it moved east all the way into New Hampshire.

Another strong cluster of storms went organized near Plattsburgh, New York, with a report of penny sized hail there, then dramatically rolled through mostly Milton and Georgia where a few tree branches came down amid downpours, gusty winds and plenty of lightning, and then into the Northeast Kingdom, 

Some strong thunderstorms also blew through parts of central and eastern Vermont a little before midnight last night.  

EVEN WORSE TODAY

Describing yesterday's weather as I did above gives you a great idea of what to expect today.  Basically exactly the same as yesterday, except it will feel even hotter and there's a somewhat greater chance of severe storms than yesterday.

The heat advisories that covered most of Vermont's broader valleys yesterday have been expanded to cover all of Vermont today.  It's fairly rare to see those heat advisories encompass even the mountain towns. 

Once again today, actual temperatures will be around 90 - which isn't extreme for this time of year. But the air will feel like it's a little above 100 degrees in the Champlain Valley and some other lowland areas of Vermont.  The "cooler" zones of Vermont will feel like the mid-90s.

This is NOT the day you should be exerting yourself outdoors. Flee to the air conditioner, please. We're really in the danger zone this afternoon for heat exhaustion and heat stroke. I notices several communities in Vermont have set up cooling stations for those without air conditioning to seek relief. I strongly encourage a visit.

You could tell this morning the atmosphere was just itching for a fight. Through the haze and humidity, you could see some jagged clouds trying to erupt. 

The sky looked tropical and volatile St. Albans, Vermont

early this morning.  Heat, and high humidity will

help fuel scattered strong to severe thunderstorms

this afternoon and evening in Vermont.

The heat and humidity are creating a lot of instability. As the day heats up, thunderstorms will again develop explosively.  

If you watch the radar you might see, for instance, a nothingburger of a shower form somewhere in the Adirondacks and then you look again 15 minutes later that nothingburger has turned into a powerhouse thunderstorm.

These fast forming storms mean you might not necessarily get much of a warning before a strong or severe storm strikes.

As is always the case, today's storms will be hit and miss.  NOAA's Storm Prediction Center has pretty much all of Vermont in a slight risk zone for severe storms today. That's level two of five alert levels and means we'll probably end up with scattered reports of storm damage today. 

It's impossible to tell much in advance which of those relatively few places will receive damaging wind gusts, but there will almost certainly be a few of those lucky little buggers by late afternoon. 

Given how much humidity there is out there, the storms will have torrential downpours. 

The storms won't really be in a hurry to get from Point A to Point B, so those torrential downpours could linger over a particular spot to cause street flooding or small stream torrents and washouts in a few places. 

The risk of severe storms in Vermont will diminish but not entirely go away by evening.  The storms will bring almost no relief from the humidity, so we have another awfully stuffy night to look forward to.  There's always a chance a clap of thunder and a quick downpour might stir you from your already uncomfortable slumber overnight, too.

DO IT AGAIN FRIDAY?

Friday morning might feel vaguely less humid, but still stuffy.  The thunderstorms will have mixed the air and brought a tiny measure of "drier" air to the surface. But that won't last long.

Moisture in the air will pool again ahead of a cold front up in Quebec and Ontario.  This all sets the stage for another oppressive afternoon and evening with - of course! - scattered strong to severe thunderstorms in the afternoon and evening. 

More on that tomorrow morning.  The cold front will cross through Saturday and you'll notice a distinct, welcome change in the air as we go through the day.  Sunday looks perfect at this point - sunny, warmish, but not that warm, with low humidity.  Also: Nighttimes will go into the 50s, for comfortable sleeping weather.