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| The area in orange, which includes most of Vermont and most of New York, is at the greatest risk of severe thunderstorms and possible tornadoes today. There's a risk, too, in the yellow areas. |
The Storm Prediction Center has upgraded the threat level from "slight" to "enhanced."
This scale is a five level risk assessment of potential severe storms. It goes from marginal, slight, enhanced, moderate and high, so you can see we're in the mid-range of the risk.
Which is a relatively high risk.
The main threat continues to be strong, damaging thunderstorm winds. Not everybody will see this, but a few of us will. I almost guarantee there will be at least some isolated reports of damage in Vermont and New York today.
There continues to be a small but real threat of tornadoes today. Winds are veering with height, so presents the possibility. The five percent chance zone - the area where there's a five percent chance of a tornado within 25 miles of a given point, has been expanded eastward from the Champlain Valley to now cover almost all of Vermont.
There's not a lot of sun to destabilize the atmosphere, so that's the only thing that would help preclude storms. There was some thought that rain showers this morning would further stabilize the atmosphere and limit storms, but those morning light showers have mostly dissipated, so I don't expect them to be a factor.
Damaging hail is still a risk, too.
The upper air dynamics are so favorable for severe storms I don't blame the Storm Prediction Center for upgrading the risk today.
While widespread flooding is not likely, a few areas that get hit by two or more torrential thunderstorms could have high water issues. Any thunderstorm could also produce street flooding and dangerous lightning.
I still think not much is going to happen until around 2 p.m. or after. But storms should rapidly develop today in New York and head east. It's going to be a very busy and possibly dangerous late afternoon and early evening in Vermont.
PREVIOUS DISCUSSION:
I hope you like busy weather days because today will be one here in Vermont and surrounding areas.
The biggest thing to worry about is the possibility of severe thunderstorms this afternoon and evening, as most of the ingredients you need for such weather are coming together.
There's high winds aloft. Winds are changing direction with height. There's plenty of moisture in the atmosphere to feed the storms.
All you need is something to trigger the storms. And..viola! A nice strong cold front coming in from the west to act as a trigger.
The biggest threat from the storms will be strong damaging winds. As is the case with all severe storm risks, only a few places will get destructive gusts. It's impossible to predict who will get a severe storm until less than an hour before it happens, so all of us have to be weather aware today and listen for possible warnings.
Here's a refresher on the general rules. If your area goes under a severe thunderstorm or tornado watch, just keep doing your regular routine but keep an ear to a weather radio or local media for updates and alerts and be ready to take action if necessary.
If you get a severe thunderstorm or tornado warning, take shelter pronto. You'll want to get into a sturdy building and stay away from windows. In the off chance you get a tornado warning in particular, it definitely wouldn't hurt to head to the basement and stay in a sturdy area down there until you get the all clear.
TORNADO?
I did mention tornadoes up above, didn't it? Here's another thing: There's actually a very slight, but real risk of tornadoes today, especially in the Champlain Valley and most of northern New York. Remember, I told you that the wind direction today is changing with elevation. Such a scenario can sometimes lead to tornadoes.
If discrete thunderstorms -- storms not part of a long line of storms that will get going ahead of the main show just ahead of the cold front today - those storms could produce a tornado. If these storms form, they would develop this afternoon over the Adirondacks and head toward the Champlain Valley.
Like I said, the chance of a tornado is low, but I bet there will be one or two, especially over New York and possibly the Champlain Valley. To give you an idea of the chances of a twister, today from the Champlain Valley west, there's a five percent chance of a tornado within 25 miles of where you're sitting. Like I said, a remote possibility, but real.
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| Areas in green and brown have a very, very slight but still real chance of a tornado today. Yep, this includes Vermont. |
As the cold front approaches, I think there will be a good line of showers and thunderstorms, a few of them severe, just ahead of it.
Some of those storms will grab some of those high-level strong winds and bring them to the Earth's surface as damaging gusts.
A few places could also get large, damaging hail stones. There's a chance one or two storms might bring hail big enough to ding cars and siding, and damage windows.
Overall, the best chances for severe storms today will be between 2 and 8 p.m. with western areas getting the storms earlier and eastern areas getting them later in that time frame.
FLOOD ISSUES?
The storms will be moving through pretty fast, so they won't linger over any one area for a long time. That's good to prevent flooding. Still, torrential downpours will come with some of the storms, so there might be street and small stream flooding.
A few flooding problems have already developed here and there due to previous showers and snow melting from the mountains. A local state of emergency was declared yesterday around Saranac Lake, New York due to flooding, which is ongoing this morning.
A flood warning has also been issued for the Lake Champlain basin, as the lake approaches its flood stage of 100 feet. At that level, some low lying roads get flooded, wave action could cause damage to camp property and places like Perkins Pier in Burlington go underwater.
The flooding along Lake Champlain is expected to be pretty minor, as things don't usually get that gnarly along the lake unless the level goes to at least 100.5 feet.
NON-STORM HIGH WINDS
Even if you don't get a nasty thunderstorm, winds will become pretty strong and gusty outside the areas of thunderstorms today and tonight. Even after the cold front goes through and the threat of severe thunderstorms ends, strong southwest winds gusting to as high as 45 in Vermont and 55 mph in New York state tonight could bring down a few more trees and power lines.
LOOKING AHEAD
Once you get through the stormy weather today and tonight, you're going to be rewarded with a gorgeous Saturday. Temperatures will be in the 60s to low 70s, and there will be quite a bit of sun.
It looks like another strong cold front will come through sometime Sunday. Unlike today, there won't be thunderstorms. Instead, there will be a fair number of scattered showers, all on the light side during Sunday. I think most of the showers will hold off until afternoon and really get going Sunday night - but there won't be any big huge downpours.
Sunday's cold front will introduce a brief shot of chilly air Sunday night and Monday. It could even snow on the mountain peaks Sunday night. (I know, you don't like the s-word, but I had to say it.)
There could also be frost Sunday night and Monday morning, and again Monday night and early Tuesday morning. Such a frost isn't the least bit unusual for our neck of the woods in early May. Still, if you brought out some sensitve plants, bring 'em indoors.
A welcome spell of dry weather is likely starting Monday and continuing probably at least into Thursday. Temperatures will also warm up again, reaching the 60s Tuesday and possibly low 70s Wednesday and Thursday.
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