After A Stormy Vermont Thursday, A Delightful Fourth, And Then Summer Returns

The first round of strong to severe thunderstorms
approaching South Burlington, Vermont early
Thursday afternoon. The storms caused scattered
wind and hail damage throughout the state, and 
disrupted some pre-Fourth celebrations 

 That NOAA outlook for yesterday indicating Vermont and the rest of New England should watch out for severe thunderstorms certainly came true. 

Numerous reports of wind damage and hail came in from all six New England states, along with New York and New Jersey and eastern Pennsylvania. 

Here in Vermont, two rounds of strong storms hit, one early in the afternoon, the next toward evening. 

The evening round surprised me a bit because it was the stronger of the two, and came after cooler air had already started arriving. 

It shows that some summertime weather disturbances can really pack a punch, even if they're not really feeding on hot, humid air to power them. 

Two rounds of damaging storms blew through Thursday. 

The first round in the early afternoon mostly affected mostly northern Vermont, knocking down trees near Keeler Bay in the Champlain Islands and cutting power to areas in and around St. Albans. The early afternoon storm knocked over a tree onto a parking lot at the University of Vermont, damaging a car.

That first line of storms made its way down to Rutland County by mid-afternoon, dumping hail. Hail the size of ping pong balls pelted East Wallingford, and quarter sized hail hit Danby. I'm sure a few people there have dented cars this morning.  

The second batch of storms roared out of New York State, crossed Lake Champlain and basically traveled down Interstate 89 before cutting through east central Vermont.  Winds at Sand Bar State Park in Milton gusted to 58 mph.

 More trees and wires came down in parts of Burlington, and in Essex, Montpelier and certainly a few other places.

At one point Thursday evening, about 8,500 homes and businesses were without power in Vermont.

Burlington does its fireworks display on July 3 and a crowd had already gathered at the city's waterfront when this storm hit. The storm prompted a hasty evacuation as lightning crackled overhead. The storms moved on pretty quickly, so fireworks later in the evening went off without a hitch, however. Montpelier also cut off its Fourth of July festivities Thursday due to the severe weather. 

 That second round of storms brought some cold air down from aloft. Thursday evening was chilly!  Temperatures were only in the upper 50s in parts of the state in the hours before sunset. 

Overall, Thursday was one of the busiest and most disruptive storm days in Vermont's 2025 severe weather season

TODAY/WEEKEND

Today, the Fourth of July, will certainly not be one of the stormiest days of the summer. 

There are a bunch of so-called "fair weather clouds" out there. Air high above us is still chilly. The strong early July sun creates updrafts of air. Moisture in that rising air condenses into clouds once it hits the cooler air, so you get some clouds. 

The sun will be in and out all day. The sunniest area will be the Champlain and Lower Connecticut River valleys.  The cloudiest areas will be in the Green Mountain and Northeast Kingdom. But everyone should see at least some sun for the rest of the day. 

Towns holding fireworks displays this evening should be A-OK, with partly clear to clear skies and great visibility. You might want to bring a light jacket. Temperatures should drop from the 70s to the low and mid 60s after sunset. Those temperatures should bottom out in the 50s by early Saturday morning, with some 40s in the cold spots.

Saturday looks awesome with generally sunny skies, and temperatures in most spots reaching the 80s. 

We're still looking at a brief squirt of hot,  humid air Sunday. Many Vermont communities will make it to at least 90 degrees.   

A New Climate Change Twist On An Old Fashioned Autumn Weather Pattern

Satellite view from late Sunday afternoon. Clouds from
former Tropical Storm Ophelia reach about as
far as Route 2 in Vermont. Wisps of wildfire 
smoke are visible in the clear air over far northern
Vermont. Much more smoke is visible in Quebec
and that will contribute to haze much of this week.

UPDATE

Quite a bit of haze out there today, Monday, due to wildfire smoke from Canada. This was expected, of course. Air quality in Vermont is not terrible, staying mostly in the "moderate' category, but not considered unhealthy. 

PREVIOUS DISCUSSION

Very often in the autumn, these big, sprawling high pressure systems stall near or over the Northeast.

We call these spells Indian Summer, and we're entering such a spell now. Technically, Indian Summer strikes after a good autumn frost. We haven't had one yet, but overall, the weather will fit. 

In the past, especially way back in the mid 20th century, the sunshine with these Indian Summer spells mixed with quite a bit of haze. That's because these huge high pressure systems  featured temperature inversions. 

Inversions are a warm layer in the atmosphere atop a cooler layer near the surface. The inversion acted like a lid, trapping pollutants. 

 The dense morning fog that is characteristic of weather pattern would sometimes become mixed with the pollutants to become smog, and that smog in some of the most industrial places in the U.S. (think Pennsylvania steel country) would never lift. 

In the worst cases, this would get deadly. The most famous case was in Donora, Pennsylvania in October, 1948, when a thick smog choked the town for five days, killing at least 20 people and sickening at least half the town. 

This incident was the spark for the Clean Air Act and other anti-pollution initiatives. 

Decades later, spells of Indian Summer weather across the Northeast were much less hazy as a result. There was less pollution in the air to trap, so skies remained deep blue, the air remained easy to breathe. 

Now, though, it appears the haze is back.  A very typical for the season big high pressure system is now stalled in Quebec, and beginning to nose more and more into New England.   The sky under much of this high, though is not a brilliant blue. Instead, wildfire smoke, which has plagued Canada much of this year, is trapped in this big area of calm, fair conditions.

So, we're going to have a week of gorgeous autumn weather - Indian Summer if you will  - here in Vermont, expect hazy skies during much or even all of this long stretch of mild, pleasant weather this week. 

Unlike Donora in 1948, a lot of this smoke and haze is aloft, and not much is near the surface. That means, thank goodness, the air won't be all that unhealthy to breathe. Most of the tiny particles in the haze that can damage lungs is high overhead. 

I noticed air quality in Vermont Sunday and this morning was in the moderate category. That means it's not exactly fresh and clean out there, but for the vast majority of us, pollutants aren't at any kind of dangerous level. 

Although I admit the following is speculation, I think the haze associated with Indian Summer is back to stay.  Summer and early autumn wildfires in Canada and the western United States will generally be more common and widespread than in the past, due to climate change. 

The smoke will swirl into these big high pressure systems that bring us Indian Summer, and we'll be back to the autumn haze of mid-20th century America. 

Bottom line for us is the clouds and sprinkles that came north from then-Tropical Storm Ophelia over the weekend are slowly eroding and heading out of Vermont. 

It's going to be a full week of mild afternoons with plenty of sun (with some smoke and haze). Highs will be in the 60s and low 70s daily all week, which is a little warmer than normal.  Each morning will feature patchy dense fog, especially in river valleys. Lows will be mostly in the 40s, about average for this time of year. 

We haven't had a stretch of dry weather as long as this since late May and early June.