After A Chilly Thursday, A Shot Of Steamy Summer Heat Coming. Storms Too?

Well, Thursday was kind of a bleak one in northern Vermont wasn't it? Overcast, patches of drizzle, temperatures in the low 60s.   

The cool weather over the past couple of days has let my peonies hang
on in my St. Albans, Vermont gardens, but a spell of hot, humid
weather will likely make them go past their prime this weekend. 

It was even worse in northern Maine. Up in Caribou, the high temperature Thursday got all the way up to 50 degrees. Yeah, chilly. It set a record for the date for the lowest high temperature on record. 

The cool, clammy air hung on into this morning, with patches of light rain here and there.

At least if you don't like hot weather, you were happy, right?

If so, you won't be. We haven't had too much in the way of oppressive humidity so far this late spring and summer, but a spell of sticky, rather hot air is coming in for Sunday and Monday.

Temperatures could get up to 90 degrees in a few Vermont spots Sunday afternoon, with most places well up into the 80s. The humidity, which is low today and won't be so bad Saturday, will get increasingly awful Sunday afternoon.

Sunday night will be a terribly oppressive night for quote, unquote sleeping, and Monday will be a miserably sticky day, too. This won't last long, but as temperatures and humidity will settle back down. 

To give you an idea of how humid it will be, precipitable water levels in the air over Vermont - one measure of moisture - will be at near record high levels late Sunday through Monday.

That sets the stage for some potentially torrential rain with some thunderstorms through that period. The first batch of storms could cross the border from Canada as soon as late Sunday afternoon or evening, but most of the activity will probably hold off until Sunday night and Monday. 

Terrific. In addition to all that humidity Sunday night, the potential is for it be quite loud out there. Don't plan on much sleep then. 

On one hand, we could use the rain. The cold front that came through Wednesday night didn't really produce a lot of heavy thunderstorms. The rain that came yesterday through this morning was quite light, so it's still pretty dry out there. 

On the other hand, it's possible the storms Sunday night and Monday might be a too much of a good thing. It's too soon to tell for sure, but despite the dry soils and the very low river levels currently across Vermont, there's still a chance of local flash flooding. Not a huge chance at this point, but it's worth keeping an eye on.

Here's why: With such high precipitable water levels in the atmosphere, thunderstorm rains could really be extremely heavy. And there are some signs there could be "training" thunderstorms, which means a line of storms each going over the same spot, like boxcars traveling down a set of train tracks 

Training storms are a great way to produce a flash flood. 

Again, no reason to panic now.  At this point anyway, if any flash flooding occurs, and that's a HUGE if, it would be pretty localized.

Most of us will just end up with wetter gardens, which right now is a good thing.