Monday, August 11, 2025

Heat, Dry Weather Still Over-Performing In Vermont; At Least Two More Torrid Days Coming

Clear skies over Taylor Park in St. Albans, Vermont
Sunday afternoon.  Yes, it was a nice summer day
but HOT. And oddly dry for a 
New England heat wave, 
The heat over-performed in Vermont once again Sunday. In Burlington, the high got up to 95 degrees, about four degrees warmer than forecast. 

.Dry air allows temperatures to get a little higher than they would if it was more humid. 

And dry it was on Sunday. The sky was nearly cloudless, with just a small amount of lingering wildfire smoke in the atmosphere.

 It's odd to see a cloud-free sky in a heat wave around here, as the humidity that usually accompanies a New England heat wave will often generate towering clouds that turn into a few scattered cooling thunderstorms. 

But the high pressure was so strong, and the air so dry that we had now showers. No clouds. No cooling. Outside of Burlington it was hot everywhere in Vermont, St. Johnsbury got to 92 degrees. It was 93 in Springfield. There was no escaping the heat up in the mountains. The summit of Mount Mansfield was at 83 degrees. 

This has been a strangely dry heat wave so far.  Dew points were in the upper 50s during Sunday. That's normally considered comfortable, but actually temperatures were so hot it sort of nullified that "comfort."   A normal heat wave would bring us uncomfortable dew points well into the 60s or low 70s. 

That's why there wasn't any kind of heat advisory on Sunday.  It was a dry heat, as they might say in Arizona.  Not as bad as the humid East, supposedly.  But when that the humid East went dry this weekend, at least in Vermont, it still felt uncomfortably hot for us in the alleged Great White North.   

The relative humidity Sunday afternoon was around 32 percent in Burlington and much of the rest of Vermont. That's awfully low. The hot sun, the hot temperatures and that dry air really accelerated the developing drought in and around the Green Mountain State. 

Needless to say the fire danger in New England and southeast Canada continues to worsen.  Around here, the Vermont Department of Forests, Parks and Recreation today upgraded the fire danger in most of Vermont from "high" to "very high" which is somewhat rare designation.

If this keeps up, we're going to have to start worrying about crops quite soon, too.

HOT, DRY FORECAST

The dry, hot state of affairs will continue for at least two more days.  What appears to be our developing drought will continue on, despite the chances of a few showers and thunderstorms Wednesday. I'll get to those in a minute.

The humidity - dew point - has crept up a little since yesterday and will stay mostly in the low to mid 60s. 

It'll be interesting to see what that slightly higher but not ridiculous humidity does to actual temperatures. The National Weather Service is going for expected highs of 93 in Burlington both today and tomorrow. 

If those temperatures come to pass, that's marginally cooler than Sunday, but it will feel a bit worse.   It's enough to finally trigger a heat advisory in the Champlain Valley.  We'll barely meet the criteria for a heat advisory, as it will feel like it's in the mid-90s this afternoon.  

The heat advisory is on in part because the longer a hot spell goes on, the more effects it has on the human body.  This has been going on for a few days now, so it's wearing us out. Vermont outside the Champlain Valley doesn't quite qualify for a heat advisory, but just know you need to take it easy in today's weather, no matter where you are.  Tomorrow, too

Probably the best you can do is accidentally shoot yourself with your garden hose while watering your veggies and flowers.   There is no chance of any welcome, cooling showers today or tomorrow. Just lots of blast furnace sun.  

COLD FRONT

The cold front to end the heat is still due Wednesday. I am still unimpressed by the prospects of a lot of rain with this thing. Chances appear good that most of us will see some rain, but it won't be much.

It will temporarily get really, really humid Wednesday, which would make you think we're going to get blasted by torrents of rain. But the atmospheric dynamics don't seem to be there to generate lots of strong storms. 

There's probably a risk of a severe storm or two but that risk is low. NOAA's Weather Prediction Center even has us in a marginal (very low) risk of flash flooding Wednesday, which might seem surprising. 

It's possible but pretty unlikely that one or two spots could get a torrential enough downpour to cause some minor washouts, that sort of thing.

 But even the lucky few that get a good downpour won't benefit much. Any local torrents won't last long, and won't have a chance to soak into the ground. As I mentioned yesterday, we need a slow, steady rain to undo the dustiness and lack of water underfoot, and in our streams, rivers and wells. 

After Wednesday, it's right back to the super low humidity and sunshine. That'll probable last Thursday through Saturday. At least the air temperature Thursday and Friday will be reasonable, with highs near 80s and lows in the 50s amid that dry air. 

There's a chance of another weak front with lame, scattered showers Sunday, but that doesn't look impressive either. That Sunday thing looks like it might be followed by another batch of dry high pressure from central Canada.

Since those two cold fronts will introduce air from central Canada, we might have a couple more big smoke attacks amid the dry air. Those two new air masses, the first one on Thursday the next tentatively schedule to arrive a week from today, are coming from those places in Canada with the huge ongoing wildfires, 

So chances are, the relatively cool bursts of air won't make you breathe easy. Instead, it could well be more smoke and gunk and haze and yuck.  

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