Oppressive Awfulness Vermont Today, New England Severe Threat Thursday

At least in current forecasts, the area in yellow has
the best chance of seeing severe storms Thurday. 

 If you hate summer heat and humidity, you already know today is the worst day so far this summer. 

In Burlington, it was already 86 degrees at 11 a.m. and the heat index was 89.  Actual temperatures are almost guaranteed to get into the low 90s today, except in the somewhat higher elevations. A heat advisory is up for the Champlain Valley, with a heat index of between 95 and 100 degrees.  

I guess you can take solace in the fact that we won't have a record high in Burlington today. That record is 99 set in 1977.

The chances of a cooling thunderstorm today are low, but not zero. You could get enough of an updraft near the mountains to develop a brief thunderstorm, especially considering how unstable the air is.

Some forecasts also have a very weak disturbance crossing northern Vermont later today, which could create a few isolated thunderstorms  this afternoon and evening. But don't hold your breath.  If any of these do develop, though, one or two of them could be strong, at least for a short while. 

We'll have an oppressive night tonight, too, and that sets the stage for a potentially dangerous day on Thursday, at least for some of us. 

The timing of the weather systems isn't perfect to set up severe weather west of the Green Mountains. That said, the whole area from the Adirondacks eastward to the New England coast is in play for rough weather tomorrow. 

The approaching cold front, and a disturbance ahead of it, will probably arrive too early in the day to do much harm, say west of Saranac Lake, New York.

As of this morning, there's some disagreement as to how soon the storms will begin to develop in northeastern New York and northwestern Vermont.  One model has strong storms just starting to develop in the northern Champlain Valley at around 11 a.m. and strengthening as they cross Vermont in the early to mid afternoon.  It then has a second line of storms in parts of Vermont in the mid to late afternoon.

Another model has not that much coverage of storms tomorrow except in eastern Vermont. One more model storms developing in eastern New York around noon, then strengthening as they cross into Vermont in the early to mid afternoon, with another line of storms following in the mid to late afternoon.

So, as usual, the severe threat is uncertain.  The models should come into better agreement by tomorrow morning, but still won't have a perfect handle on things. 

A very, very low, but not zero chance of another 
tornado Thursday. Anyone in that green zone has
just a 2% chance of having a tornado touch
down within 25 miles of them. 

The bottom line is expect at least some severe storms anywhere in Vermont tomorrow, with a slight edge to the eastern half of Vermont with getting hit with the worst of it. Just like last time, on July 12

Damaging winds are the biggest threat from tomorrow's storms. Meteorologists are still expecting strong winds aloft. The storms can grab these winds and blast them down to the surface. And in the process, push down a lot of rain and hail, which would accelerate the winds even further. 

If some storms get going ahead of the main lines of storms, these discrete things can become supercells, which would also risk high winds, hail, maybe even another tornado. 

As the storms mature, some of the lines of storms might take on the shape of a backwards C.  The storms that are at the very front of that backwards C could really have especially damaging winds. 

There could be isolated instances of flash flooding with the storms' torrential rain. However, the storms will be moving right along, meaning the rain won't last super long in any one spot, so they won't have a chance to deposit inches of rain. 

Things will quiet down Thursday night, and stay mostly quiet Friday and Saturday. The cold front that's coming in won't actually have any cold air behind it, so it will stay quite warm Friday and Saturday.

Another system has some chance of giving us more heavy rain and strong storms Sunday.