On Flood Anniversary, Vermont Risk Of Flash Flooding Increases A Bit, Still Not Nearly As Dire As Last 2 Years

Parts of Vermont and northeast New York got a slight
bump up in the risk level of severe storms. Earlier
forecasts had us in the dark green marginal risk
meaning isolated instances of damaging winds.
It's now "slight" meaning scattered instances, not
just isolated cases of bad storm winds. 

UPDATE 1 PM THURSDAY

NOAA's Weather Prediction Center has increased the risk level for flash flooding in Vermont this afternoon and evening. 

Instead of a marginal risk of isolated instances of flash flooding, (level 1 out of 4 risk) we're at what is known as slight risk, which is level 2 out of 4 in the risk categories.

This means instead of just a 5 percent chance or so of seeing flash flooding within 25 miles of your location, there is now a 15 percent chance or even somewhat better than that chance of seeing flooding in that radius.

This is because the developing storms are slow movers. We could see pockets of two to four inches of rain in a few spots. 

Flash flooding could happen anywhere around Vermont today, , but I still think the highest chance of flash flooding is in the Northeast Kingdom, where there have been local downpours all morning. 

Ominously, a flood warning already had already been issued around the town of Orleans in the Northeast Kingdom

I'll emphasize that we're still NOT going to see anything nearly as widespread or destructive as we did on July 10-11 last year or the year before. 

Most of us will be just fine today and tonight, and most of us will still see much less than two inches of rain.  An inch of rain, if you manage to get that, won't cause any flood issues. 

Updated risk map increases the flash flood threat in
Vermont a bit to slight, level two out of four on the
risk scale, as you can see below, it was earlier
just marginal, a level one out of four on the risk scale,

But I do think there will be some scattered areas of trouble in Vermont today. This could be the third year in a row with flood issues on this date. 

Stay tuned to your weather radar through the day and into the evening to receive warnings of local flash flooding or spots where severe thunderstorms could trigger damaging winds. 

PREVIOUS DISCUSSION

I guess July 10 and 11 have become a weather tradition in Vermont. 

It seems either something really bad happens, like the big floods of July 10, 2023 and 2024, or everything is fine, but something interesting happens with the weather. 

Not every July 10 and 11 is weather weird, of course. Historically, most of them are pretty routine, like any date of the year. But the dates often bring at least something vaguely noteworthy. 

The chilliest temperature of July, 2022 in Burlington came on July 10.  The low of 50 was not all that cold for July, but is still the coolest July temperature since 2015. July 10, 2020 was the hottest day of the month, with a high of 95 and a low of 75 in Burlington.

When I was a kid, July 11, 1976 stands out as one of the worst local flash floods I've ever seen, striking parts of Rutland County. Going way back to 1888, it snowed like hell for a time on the Green Mountain summits. 

As mentioned in my Wednesday post, today won't be a repeat of the hell we went through in 2023 and 2024. 

Today will just bring us some interesting doses of showers and thunderstorms.  Some of which seem destined to cause local spots of trouble here and there in the Green Mountain State.   So you'll need to stay on your toes. 

THIS MORNING'S SET UP

An area of heavy rain that caused flash flooding in the Mid-Atlantic States last evening moved into southeast New England today, where flash flooding from up to six inches of rain hit earlier this morning 

We don't have to worry about those annoying downpours,  as they will keep moving off to the northeast off the New England coast.

But here in Vermont, it was already a bit interesting as of 8 a.m. There were already some widely scattered pinpoint, slow moving downpours around the state. 

That's a hint right there we will have no trouble generating a bunch of showers and storms during the day today. It's hard to know exactly how each storm will develop and move, but what follows is a decent guess. 

Flash flood risk in Vermont is still marginal, meaning at
most isolated instances os flash floods. The yellow areas
have a somewhat higher risk of flash floods. 

Breezes going up the slopes of the Green Mountains should generate storms along those mountains. Maybe pretty early in the day, before noon.  Those should then drift eastward into the Northeast Kingdom and the Connecticut Valley.

The rest is complicated. The storms could generate outflow gusts that will interact with other weak disturbances coming in from New York State, which would then drift eastward into the Champlain Valley later this afternoon. 

 Eventually, they'll head through the Green Mountains into the eastern Vermont toward evening.

Other random storms could pop up just about anywhere else during the day and evening today.  

Most of the storms won't be super awful. However, the Storm Prediction Center has upgraded much of Vermont and northeast New York  to a level two slight risk level for severe storms, which means scattered instances of severe storms, Until earlier this morning, the risk forecast was lower with only a marginal risk of isolated instances of severe storms.  

If severe storms form, they'll produce damaging winds in a few spots. There's also a risk of damaging hail, but that risk is pretty low. 

The storms will also move sluggishly.   With heavy downpours. If you're unlucky enough to have a storm stall over year, or get hit by several of them, there could be a local flash flood problem. NOAA's Weather Prediction Center is still watching the current marginal risk of local flash floods.  

As of today, it would take probably two inches of rain within three hours to start flash flooding in most parts of Vermont.  A few isolated places in the state could see up to three inches in that time frame, hence the small risk of those flash floods,

I'll emphasize that the vast majority of us will see much less than three inches of rain today, which is why we won't have any widespread problems with high water. Still, take any flash flood warning seriously. If you're under such a warning, stick to high ground. Don't drive over a flooded road, as it could be washed away or undermined.

A flash flood could develop anywhere, but I'd say they'd happen in the Green Mountains or Northeast Kingdom. 

You'll want to have a weather  radio with you today, or at least some way to receive severe thunderstorm or flash flood warnings, just in case. 

But again, Ill stress that meteorologists expect nothing close to the scale we saw last year and the year before.  

HEAT

It's humid out there, and it will stay that way. The little boundary in New York that's helping to set off today's storms isn't really a cold front. It will have gone by us tomorrow, so we expect storms to be few and far between on Friday.

Temperatures are  going to go up again, too. The clouds and storms should hold temperatures today in the upper 70s eastern Vermont to low 80s west.  Starting tomorrow and on through at least next Wednesday, daily highs in Vermont should get into the mid and upper 80s. With a few 90 degree readings thrown in here and there.

The humidity will stay high, so nights will be stuffy too.  Not a good week coming up if you don't have air conditioning, I'm afraid.

Given the heat and humidity, there's a chance of a scattered storm or two each afternoon and evening, but most places will be dry most of the time. The best chances of storms at this point look like they'll be around later Sunday and maybe Monday.