Thursday, July 21, 2016

"Ring Of Fire" Storms To Harass Vermont, Other Parts Of Northeast

Storm damage in Minnesota today. Severe weather is
possible in parts of the Northeast starting before
dawn on Friday.  

Starting early this morning Vermont and other parts of the Northeast is getting a side effect of that torrid heat wave in the middle of the country.

I saw this coming days ago. 

A strong ridge of high pressure is anchored over the middle of the country. The sinking air and the warm influence of the midsummer sun is creating a terrible heat wave underneath this massive area of high pressure.

This type of thing often happens at least once or twice a summer. When it does, something called the "Ring of Fire" forms along the outer edges of this heat dome, which is basically another way of describing this hot zone of high pressure.

Little disturbances ride along the northern edges of this heat dome. The disturbances - mostly weak cold fronts or pockets of chilly air high in the atmosphere, interact with the heat just to the south to create fast moving zones of severe thunderstorms.

That the air to the south is so hot makes the severe storms all the worse.

Wednesday night, one of those storm packets zipped across parts of North Dakota, Minnesota and Wisconsin. Some of these storms packed winds of 70 mph or more. Some unofficials reports indicates winds of up to 100 mph.

It got so bad early this morning in Duluth, Minnesota that they basically banned travel for awhile this morning because of all the fallen trees around the city.

At least two people died in the Minnesota storms.

We here in Vermont and much of the rest of northern New York and New England are now about to enter this "Ring of Fire" as that heat wave lurks just to our southwest.

It's turning more humid here, and will stay muggy through the weekend. The air will stay quite warm, with daily highs in the 80s, so that's what the weather disturbances will feed on to create a severe storm risk for the next few days around here.

The storms will come in waves, and forecasting these things are tricky. The timing of the weather disturbances and cold fronts is key, and it's hard to predict those more than 12 hours in advance in this type of weather pattern.

The forecast will change, but here's how it looks like it will play out at this point:


I had wondered if the band of storms that trashed Duluth and other parts of the upper Midwest would become severe here this morning.

It turned out they didn't, which is a good thing.   A band of showers and thunderstorms did cross through Vermont in the early morning hours, but I have no reports of anything wild.

It didn't rain all that much either, but we'll take what we can get. It's still pretty dry out there.

In the wake of this early Friday morning's band of showers, a zone of higher pressure - sinking air - has come in. We'll get a fair amount of sun, so we'll have no trouble getting temperatures well into the 80s this afternoon.

It's gotten more humid, too, so it'll be kind of uncomfortable.

Meanwhile, higher up in the atmosphere, a layer of dry air is moving in. For the first half of the day that will reinforce the sun, and make showers and thunderstorms unlikely into the early afternoon.

But that dry air aloft will be a factor that could turn this Friday late afternoon and evening into a bumpy one for northern New York and much of New England, including Vermont.


A weather disturbance and weak cold front will be approach us from the northwest later today.  It's part of that "Ring of Fire" weather pattern I described above.  That will cool the atmosphere off way up there overhead.

That will set off another round of thunderstorms during the afternoon and evening, and some of those could get severe. Strong winds and hail are the biggest threats.

What will happen is those billowing tall thunderstorm clouds will poke upward into that layer of dry air I told you is hanging around aloft.

The dry air would evaporate some of the moisture bumping up into it from the clouds rising up into it. Evaporation cools the atmosphere, making it more dense. So, the newly cooled air will start to zoom downward toward us, gaining momentum from the rain falling in the thunderstorms.

This dropping air will also grab onto some stronger winds blowing aloft and bring that down to the surface, too. When that happens, you get a great gush of damaging winds - a thunderstorm microburst. There's your severe weather today.

By the way, these gushes of wind coming down from aloft can also some pack some big, damaging hail in some instances.

Now, this won't happen everywhere.  A lot of places will get showers and storms across Vermont and the rest of the Northeast toward evening. But only a few thunderstorms will able to fully work the magic with the dry, windy air aloft.

So  like all the severe weather outbreaks we've gotten this summer - and most severe weather outbreaks in general, only some towns will get damaging winds and hail. Just scattered instances of blown down trees and power lines.

 Still, keep an eye to the sky and heed warnings. And just like on Monday, no boating or  hiking, please on Friday. Too dangerous and these storms can whip up awfully fast.

The storms will wane later Friday night, and things should be fairly quiet after midnight and Saturday morning.


Another disturbance is likely to ride the Ring of Fire into the Northeast Saturday afternoon, smashing into air that will remain humid by that point.

Many more showers and storms will develop. Some might be strong to severe but it's hard to pull apart the details of what will happen just yet.  I don't think there will be as many severe thunderstorms as there will be today. (and remember there will just be pockets of severe weather here and there today.)

I do think Saturday's showers and storms will get going earlier than today's round will. There could be rain any time Saturday, but the most likely time you'll get a storm is during the afternoon and early evening.

The storms will die out by midnight Saturday.


A break. There will be few if any showers and storms, and humidity will go down somewhat as we're between systems in Vermont and most of the rest of the Northeast. There will quite a bit of sun, too. A nice day. The day you should go out and enjoy this weekend without worrying much about storms.

MONDAY: Another round of strong storms is possible as yet another Ring of Fire disturbance comes in. It's too early to say for sure what exactly will go on then. It all depends on when the disturbance comes through.

If it arrives in the afternoon, it could kick off some scattered strong storms. If it comes through later at night, I imagine we'll just get garden variety thundershowers overnight Monday into very early Tuesday morning. Stay tuned.

TUESDAY-THURSDAY: The heat ridge might get suppresed further to the south and west, lessening the chances of more storms during that time frame. Temperatures will be near or just a little above normal, too. Expect quite a bit of sun, too, so early indications are the middle of the week will bring us a nice stretch of summer weather.

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