Tuesday Morning Update: Big Severe Storm, Tornado Threat Still Looms In Northern New England, With Wildcards

The areas under the gun for severe weather look
unchanged since yesterday. The latest NOAA
Storm Prediction, issued at 8:30 this morning,
still shows an enhanced, level three out of five
risk of severe storms and possible tornadoes
the evening across northern New England
Orange area is at highest risk

 Dawn broke early this Tuesday morning in a way that did not suggest super hot temperatures and an oddly intense severe storm outbreak was on the way. The sky was overcast with wildfire smoke making yet another appearance early today. 

That suggests a drab but peaceful day would be in the works. "

But nope! The weather forecast that we saw yesterday is basically unchanged from the one we had yesterday.  

A hot day looms, and worse, we're still on track for severe thunderstorms and possibly a tornado or two this evening and overnight. Mostly in northern Vermont. 

The clouds are from a large but dying cluster of thunderstorms up in Quebec.  Those clouds will dissipate and move east and out of our hair later this morning. 

One storm in Quebec, a little north Sherbrooke, looked intense as of 9 a.m. That storm, if it holds together, could spew some large hail on the extreme northeast corner of Vermont and on far northern New Hampshire later this morning.  

Other than that, very likely we'll see no storms until the main show this evening. 

The wildfire smoke will linger all day and into the night. We hate wildfire smoke for obvious reasons, damage to our health being one of them. But there's a chance the smoke could do us some favors in terms of how hot it will get today and how severe the storms will get tonight. 

Don't count on that though. It's still going to be hot today, and the risk of intense thunderstorms is still high for at least some of us. 

I'm going to bury the lede and talk about the heat first, then the storms. There's a lot here, so bear with me. 

TODAY"S HEAT

As noted, the smoke is a bit of a wildcard. It's looking pretty thick on satellite images. Enough to block some of the sun's heat  and possibly make it a little cooler than forecast. For instance, the National Weather Service is going for a high of 97 degrees in Burlington today. 

That might well happen, though the smoke could hold temperatures down into the low 90s if it stays thick enough. It'll still be hot and humid, of course. And the smoke in the air will make things worse for people with health problems. The heat and the smoke will team up for a one, two punch for Vermonters whose lungs and cardiovascular systems have already been battered by illness. 

Take it easy all day.

THE STORMS

As a foreshadow to this evening, weather radar picked
up an intense storm just north of Sherbrooke,
Quebec as of 9 a.m. That storm, if it holds together
could dump large hail on the extreme northeast corner
of Vermont and far northern New Hampshire.
Otherwise, the severe weather should hold
off until this evening. 

This is probably what you came here to see updates. The wildfire smoke adds a wildcard to this forecast, too. I'll get into that in a bit. 

The overall scenario is pretty much the same as I described in yesterday's post. Ahead of a cold front, big thunderstorms will erupt in southern Canada and southern Ontario Ontario. Those regions are in for some powerful thunderstorms and maybe a few tornadoes. One or two of which might be quite strong.  

Environment Canada already has a severe thunderstorm watch in effect for these areas.

Late this afternoon, those will start heading south and begin to cross the border into the United States sometime after 7 p.m.  

The big threat hours across northern Vermont, along with far northern New York, northern New Hampshire and interior Maine are roughly between 8 p.m. and midnight. 

Those areas are under the Storm Prediction Center's enhanced risk for severe storms, a level three out of five alert level. 

Areas just south of that band are at risk of severe storms and tornadoes, too, but the risk isn't quite as high. I would say places south of Route 4 in Vermont are pretty safe from severe weather tonight, though there might still be some pretty strong storms near Rutland or White River Junction toward midnight or a little after. 

The reason for this north to south gradient in risk is timing. The potential intense storms lumbering across the order will do so toward the end of the day. After sunset, conditions start to work against severe thunderstorms. 

They'll maintain their juice for a couple hours after sunset. Then, as they head south later tonight, the storms will begin to lose their steam and weaken. By the time they reach Massachusetts, the storms will pretty much have gone pfft. 

Wildfire Smoke

There is a chance that the thick wildfire smoke might help blunt the development of these storms. The smoke could make the storms weaker than they otherwise would be. But don't count on it. Not at all. The atmospheric dynamics still look easily strong enough to overcome the effects of smoke.

Plus, how smoke affects severe storms is still poorly  understood. If you still see a lot of smoke in the atmosphere this evening, don't relax. We could still see some wild weather. I'm only mentioning the smoke as a slight glimmer of hope against the storms. I'm absolutely not promising anything here. 

The latest update on the situation from NOAA's Storm Prediction Center, issued at 8:30 this morning has not backed off at all on their prediction of the severe threat. 

THE RISKS

Everything that you can possibly worry about in storms will be something to think about tonight. Here's what to look out for:

Wind

By far, the greatest risks from tonight storms are intense straight tine winds. As is always the case in severe weather outbreaks, many of us will miss out on the destructive winds. But some of us will see them, of course. 

The more intense storms could easily have gusts over 75 mph. You'll want to me on the lowest floor of a sturdy building, away from windows if anything like that comes through. Fine with me if you hide in your basement in that kind of weather. It's the safest place. 

Most of the storms will come at us in clumps or relatively short lines. Lines of storms will team up to produce locally destructive winds. If you see a line on weather radar that's shaped like a backwards "C", looks out. The forward portion of that backwards "C" could well have intense winds.

NOAA's Storm Prediction Center continues to note that supercell thunderstorms may well be in the mix, ,especially in the enhanced risk area. 

Tornadoes

The vast majority of us in the North County will not see a tornado. A few unlucky people could, however, endure a twister. 

NOAA has the enhanced risk of severe weather in a 5 percent zone for tornadoes. That means that if you're standing at any point in the 5 percent areas, there is at least a 5 percent chance, but less than a 10 percent chance that a tornado will hit with 25 miles of where you are. 

 This outbreak poses the risk of a stronger tornado.   An EF-2 tornado has winds of 111to 135 mph, so they are more destructive. EF-3s go rip to 165 mph. 

The greatest risk for intense tornadoes seems to be in Maine, but the risk of those strong twisters still extend across northern New Hampshire, Vermont and New York. And it might not be just the supercells capable of producing a tornado. There might be enough rotation in those lines of storms to produce a twister or two. 

 Vermont, and for that matter northern New York, New Hampshire and interior Maine almost always see tornadoes that area at EF-0 or EF-1 intensity with winds of 110 mph or less.

Stronger tornadoes in Vermont are exceedingly rare. As far as I could find, the last EF-2 in Vermont hit Colchester in 1983.  There was an EF-3 listed for Bennington County back in 1998, but I believe that twister was EF-3 in New York, but weakened to a EF-1 by the time it crossed the border into the Green Mountain State. 

Hail

Some supercells, if they develop, might contain large hail, maybe the size of hen's eggs or even a little bigger. THat's more than enough to trash cars, windows and siding on houses and buildings. 

Flash Floods

The risk of flash floods is pretty low, but definitely not zero. Rainfall with these storms will be intense, so an inch or two could come down within an hour in a few places. That's enough to set up some small steam and creek flooding, washouts along steep roads, that kind of thing. 

Lightning

These storms will probably put on quite a light show. There should be quite a bit of cloud to ground lighting, so it will be dangerous to be outside, even if it's not windy or hailing where you are.

WHAT TO DO

First of all, don't panic. This is definitely a more wild severe storm potential than we're used to in the North Country. But like all severe weather events, a few of us will be very unlucky and get nailed while the rest of us come out pretty much unscathed. 

Even in those enormous Midwest tornado outbreaks that mow down entire neighborhoods and villages, a small minority of the region's populace is victimized. 

But while you're not panicking, there's a few things you should do. If you're camping in the woods, either in a tent or RV, get out by late afternoon. Tents offer no protection from falling trees obviously. RV's also offer basically no protection, and they can be blown over and upside down in strong winds. 

That sort of thing happened in Lancaster, New Hampshire when a supercell hit that area. 

If it turns out your campsite was undamaged from tonight's storm, you can head back there tomorrow morning. 

For those of us who are not camping, secure the lawn and deck furniture, and the potted plants that might tip over. You might also want to park your car away from big trees. 

Power up your devices by evening, because if these storms develop, we'll have quite a few power outages. If you live in a remote, woodsy area, be ready with LED candles and non-perishable food.

A handful of places might be out of electricity for days. And remote roads could be blocked for some time by fallen trees.

A severe thunderstorm or tornado watch will likely be issued later today. If your area is under a watch, continue what you're doing, but have a weather radio or other reliable source near you to receive any upgrades to a warning. 

If you receive a severe thunderstorm or tornado warning, immediately head to the basement or an interior windowless room in your house. 

If you are in a vulnerable structure like an RV or mobile home and you eceive a tornado warning, wear a bicycle or motorcycle helmet if you have any. That will protect your head. Huddle under blankets and such in a small space like a bathroom or closet. 

There is no record of anybody ever dying from a tornado in Vermont. Let's keep it that way. 

After the storm, stay inside. It'll be dark out. You won't easily be able to see live power lines, sharp objects and other hazards. In a worse case scenario, if you have to leave your house due to damage, wear sturdy shoes