Perfect Vermont Summer Weather Ends, Looong Stretch Of Downpours, Humidity Coming

Deep blue skies Thursday over St. Albans, Vermont on a
perfect summer day.  We won't be seeing anything like
this again for quite awhile. 

 If there were a DoorDash type of business in which you could order in the kind of weather you want, and I ordered a perfect summer day, you'd end up with Thursday. 

Thursday was a strong candidate for the best Vermont weather day or Summer '23. 

 It was warm enough to enjoy a dip in the lake, but the humidity was so low that you'd feel cool and refreshed after your dip. 

It was also mild and dry enough so that a hike up, say Camels Hump would be perfect. I imagine some of last week's mud would have dried up by now. 

There was enough of a slight breeze to power a sailboat, but not nearly enough wind to make Lake Champlain choppy y or dangerous. 

The sky was a brilliant blue, with just a hint of haze to remind you it's summer. High pressure blocked clouds from coming up from the south, and also blocked Canadian wildfire smoke from smothering out the azure sky. 

I hope you liked Thursday. You're not going to see anything like that for quite awhile. Expect a long stretch of humidity, clouds and rain. Some of that rain could down pretty hard. 

Let's get into the details:

HUMIDITY

Savor the last bit of dry air this Friday morning, we're in for what might be a week of oppressive weather. As our nice dry, clear high pressure system departs, south winds will gradually bring the  humidity in today.  By this evening,  you'll feel it.   

There won't really be any hot weather with our upcoming stretch of Louisiana style humidity. We'll have too many clouds, showers and thunderstorms for anything heat wave-ish. But the humidity will be very noticeable, especially at night. 

A good way to judge how humid it is to to look at the dew point. The dew point is the temperature to which the air must be cooled to become fully saturated with water vapor. 

If the dew point is under 60 degrees, like it was over the last few days, it feels pretty comfortable out there. Between 60 and 65 it feels kind of sticky.  Anything over 65 is just plain yuck. 

It's looking like most of the time tonight through the middle of next week will have dew points at or above 65 degrees. 

Usually by this time of year, we've already had a few spells of at least sort of humid weather, to get us acclimated to wet air. Not this year. It's been mostly dry, dry air. Except when it rained. But until now, the rain came with cool temperatures. 

With the lack of humidity so far, this muggy spell will definitely feel like a wet slap in the face. Especially since it will last so long. We can handle one or two days. But I'm sure a week of this will get tiring. 

With all the expected clouds, daytime highs will be in the 75 to 82 degree range for the next several days. That's about where they should be this time of year. But overnight lows will stay in the 60s to low 70s for most of us. That's warm compared to normal. 

LOTS OF RAIN

The next aspect of this upcoming stalled weather pattern is rain.  Since our friendly high pressure system is a little reluctant to depart today, I don't think you'll see any rain drops in Vermont today.

But you definitely will see that rain, starting late tonight. 

Yesterday, forecasters were telling us to expect rain every day Saturday through Wednesday. This morning, they're hinting that rain might go beyond next Wednesday and extend all the way to next weekend. 

It won't rain all the time during this stretch. But there will be lots of showers and thunderstorms, especially in the afternoons and evenings. 

Last weekend's rains dented but did not destroy what had been a developing drought in Vermont.  The rain a week ago cut in half the size of the area in northern Vermont considered in drought. Now it's just 10 percent of the state, mostly in Lamoille and eastern Franklin counties. Two-thirds of the state is considered to still be on the dry side. 

If the current forecast pans out, we'll see a lot more damage to the dry conditions, which of course is great news. 

Over the next seven days, it looks like we'll generally see two to as much as four inches of rain in Vermont. That would put June's total rainfall above normal, which is a surprise given how dry we started out this month. 

FLOODING?

With all this rain, there's actually some risk of flooding. It won't be anything widespread, and we're definitely not going to get anything like 2011's Hurricane Irene disaster.

However, if some unlucky towns have thunderstorms plowing through day after day, then have a train of them come through one after another during an afternoon and evening during the upcoming week, you can get a nasty local flash flood. 

Something to watch out for, definitely.  You won't know if or where there will be flash flooding until it's happening, or shortly beforehand. Just stay aware of warnings if you're in a flood prone spot over the course of the next week

SEVERE WEATHER?

Though we expect lots of thunderstorms - and you should always respect lightning - at least at this point, it doesn't look like there will be any widespread severe thunderstorms.

However, the weather pattern does make us prone to wet microbursts. The term sound like it refers to a small water balloon popping, but that isn't it. 

A microburst starts when a strong updraft suspends a lot of rain and some hail up in the cloud.  Then the  updraft abruptly fades, so all that rain and hail rushes to the ground in one great big whoosh. When it hits the ground, the wind spreads out.  Places near where the down rush hits the ground get strong, damaging winds. 

It's called a microburst because the damage area is usually quite small, almost always less than 2.5 miles diameter and often much smaller than that. 

The types of thunderstorms we're expecting in the coming days have the potential to contain microbursts.  But since the areas suffering damage from this phenomenon is small, the vast majority of us will be just fine.

WHEN WILL IT DRY OUT?

The short answer is, we don't know.  Some forecasts push a cold front into Vermont by next Thursday, which would help.  But other forecasts have strong high pressure off the East Coast, which would prevent that cold front from reaching us, or at least slow it down. 

The only thing I can say for sure is get used to the humidity and showers. You're going to have to.