1 PM Thursday Update Severe Thunderstorm Watch Up In Vermont , Storms Firing Up Now

One of the first developing thunderstorms of the day
pictured here beginning to loom over St. Albans, 
Vermont at around 1 p.m. A severe thunderstorm 
watch is in effect statewide. 

A severe thunderstorm watch is now in effect for all of Vermont and adjacent areas of New Hampshire and eastern Maine until 8 p.m. this evening. 

 Conditions were close to ideal this morning and early afternoon for storm development. There was more than  enough sunshine to boost temperatures and create more instability. Gawd knows there's plenty of moisture available for storms. 

And a cold front is in southern Quebec, slowly moving toward us and providing the trigger for storms.

 A path was being cleared for that cold front by slowly dropping temperatures high up in the atmosphere. That increasing contrast between the high heat at the surface and  cooling temperatures aloft are great for thunderstorms. 

One measure of the potential for thunderstorms is CAPE, or Convective Available Potential Energy, which  helps meteorologists gauge where the best conditions are for the updrafts that create thunderstorms. 

Interestingly but not surprisingly, the first severe thunderstorm warning today was issued at around 12:35 p.m. today for the area in and around Vergennes and Middlebury. That's where the best CAPE was measured prior to storms firing up.

There's plenty of this CAPE for storms in the rest of Vermont and surrounding areas, so anybody is up for a thunderstorm. That slight risk zone for severe storms, a level two on a five point scale, has been expanded northward to cover all of Vermont, not just areas south of Route 2. 

Not everybody will see a severe thunderstorm, of course, but the big storms will be more numerous than the very scattered ones yesterday. 

While storms with a severe potential will hit statewide, NOAA's Storm Prediction Center says the best bet for the severe potential is south of a line from  roughly St. Albans to Lyndonville, and north of a line from Manchester to Springfield. 

Wherever any severe storms hit, by far the biggest problem is intense straight line winds that can easily blow down branches and trees. That would be made worse if those trees fall on any power lines, cars or houses. 

We could see some hail in the most powerful storms to come through. Tornadoes are highly unlikely, I wouldn't worry too much about that. 

Even if your particular thunderstorm or storms today don't turn out to be severe, they'll still be dangerous. I expect plenty of cloud to ground lightning. Locally torrential rains could touch off a few isolated instances of flash flooding, too. 

The risk for storms will gradually decrease this evening as we get the waning influence of the sun, and the day's thunderstorms take the energy out of the air, leaving less fuel for new storms. 

As you already noticed, the heat is really on before the storms hit. After lingering near a stuffy 80 degrees in Burlington from about dawn to 10 a.m., temperatures rocketed to 92 degrees by 1 p.m. 

If the storms hold off for a couple more hours, todays' record high of 95 degrees is in jeopardy of falling. 

Wednesday Afternoon Vermont Heat/Storm Update

 It'll probably be one of the worst weather days of the year by the time we finish up today, depending on your tastes.

As expected, the heat and humidity have built up even more than yesterday. Scattered thunderstorms have also been developing, and rains from those have only added to the humidity. 

Satellite photo from a little after noon shows a severe
thunderstorm over northern Vermont near Canadian
border, a former strong storm over eastern Vermont
showing signs of a revival, and more storms developing
in eastern New York. Extreme heat/humidity and 
storms will continue all afternoon. 

Temperatures will actually be all over the place this afternoon, with most places solidly in the low to mid 90s with a heat index easily around 100.

From now through sunset is a great time to find a cool place, don't exert yourself outside and stay hydrated.  

Thunderstorms are proving to be an interesting part of the mix. 

NOAA's Storm Prediction Center singled out eastern New York, Vermont and New Hampshire as a likely place for widely scattered severe storms this afternoon 

While they won't be widespread enough to warrant a severe thunderstorm watch, we should still really be on the lookout for these things.

 They've already started.

As I mentioned this morning, many of them form super quickly. One storm formed as just a small cloud with a sprinkle under it on the west shore of Lake Champlain at around 10:50 a.m. By the time it was over Swanton and St. Albans just over a half hour later, it was a strong storm with torrential rains, frequent cloud to ground lighting and winds gusting to 30 mph. 

Less than 15 minutes after that, it was a storm carrying a severe warning with possible gusts to 60 mph heading into Sheldon and Enosburg. 

Within 15 minutes of the storm ending, it was sunny, hot and humid again in St. Albans. This is the type of afternoon we'll have all day in Vermont. Always a risk of a quick pop up storm with dangerous lightning and downpours, and that constant oppressive feel. 

In other words, a typical July day in South Florida. 

We'll do it all tomorrow too.

So today, stay safe from the heat, the humidity the lightning and the storms