A Weird, Flooding Vermont Storm Thursday and Ida

Yesterday's stalled thunderstorm over central Vermont
made a spectacle of itself and was seen far and wide in the
Green Mountain State. This is the storm as seen through
the windshield of a car traveling southbound on 
Interstate 89 in Winooski, about 55 miles from the storm.

UPDATE SATURDAY AFTERNOON

It turns out there were a couple late breaking damage reports from this storm. 

Reports are that Texas Falls Road near Texas Gap just outside of Granville was washed out.  

I'm not surprised given the torrential rains in the area and the steep terrain at that locale. 

It also looks like wind associated with the storm uprooted some trees on Patterson Hill Road in Granville. 

I'm not surprised by that, either 

The storm became warned as severe for a time late Thursday afternoon when it was intense enough to cause strong winds. That was about the time the photo in this post was taken, and those were when the storm's updrafts were strongest, and most likely to produce some downburst type winds. 

UPDATE: 3:30 pm

There were no reporting stations in Vermont that I'm aware of that got bullseyed by this storm.

The nearest town to the storm that reported was Rochester, which reported 0.25 inches of rain.  Rochester was outside the area where the storm stalled, so that makes sense.  Braintree, a little east of Granville, also got 0.25 inches of rain, but they were also outside the footprint of the stalled storm.

I also don't see any confirmed storm damage reports.  That's because this dangerous storm luckily hit a pretty remote area.  Imagine the damage if this storm stalled a little further north over Waitsfield, or a little further south over Killington! 

PREVIOUS DISCUSSION

 A small, strange, strong and potentially dangerous thunderstorm developed over the central Green Mountains Thursday and made quite a spectacle of itself.  

It wasn't big in area, but just sat over the mountains near Granville and Hancock for hours, likely unleashing a damaging flash flood in a relatively small area and befuddling any weather geek that was witnessing it. 

Weather is strange and there goes your proof. 

As we all know, it was hotter than hell in Vermont Thursday. Heat indexes in the Champlain Valley were in the upper 90s and the humidity was unbearable.

With a cold front slowly approaching from Canada, it seemed like we were ripe for thunderstorms. But forecasters were correctly unimpressed.  The cold front wasn't close enough to fire up a lot of thunderstorms and there were few other triggers for them. 

There was a thick layer of very warm air in the atmosphere, and any updraft would have to poke through that warm layer to erupt into a thunderstorm. That would be hard to do.

The only thing that could trigger a storm would be if terrain created a decent enough updraft to get things going.

Sure enough, storms Thursday were few and far between and weak and short lived. Except in the mountains east of Middlebury. 

An updraft against the slopes of the Green Mountains managed to break through that layer of warm air and triggered a thunderstorm after 3 p.m.  

And there it sat over that mountain. And sat. And sat. It finally moved out of its position shortly before 9 p.m. and drifted slowly south before eventually dissipating.. 

Radar estimated two to six inches of rain, possibly even more, fell under that stalled thunderstorm. The area where it hit is pretty remote, so reports haven't really filtered in yet as to how extensive the flooding was. 

We know it had to cover a rather small area, because the storm itself did.  The downpours were over steep and rugged terrain, with plenty of small streams and vulnerable gravel back roads and such.  So the flash flooding could have caused some real damage. We'll just have to watch the news later.

Meteorologists and weather geeks will puzzle over this storm for awhile, as it was a strange one, but the National Weather Service in South Burlington was very kind and clued me in on a lot of what was going on when I asked last night 

The wind through a deep layer of the atmosphere was all coming from the same direction.  So that updraft that started with the mountain sustained itself and helped the storm "back build."  That meant as the original storm began to move off the mountain it was anchored to, a new storm took its place on the mountain and the process repeated itself over and over again. For hours. 

The storm was isolated and surrounded by generally clear skies, so it was visible from great distances, often 70 or more miles away.  Residents of the Burlington and Plattsburgh areas had an awesome view of it. 

At sunset, the towering cloud glowed bright orange.  As darkness settled in, the cloud crackled with lightning, providing probably the best natural light show of the summer. The cold front approaching from the north was finally able to nudge the storm off the mountains near Granville around 9 a.m. as mentioned, and the flash flood threat eased.

That well anticipated cold front was limping through Vermont early this morning.  It is already less humid in the north and will turn less humid south during the day.

That's only a temporary reprieve, as the humid floods back in Sunday and Monday.  Luckily that bout of oppressive weather won't last long as a stronger push of drier air will come in for the middle of next week

FUTURE  HURRICANE IDA

Tropical Storm Ida was strengthening steadily as it approached western Cuba this morning.  Its sustained winds were up to 60 mph at last check.  

Forecasters are really, really worried about Ida. At this point, all signs point toward it strengthening rapidly and striking somewhere in or near Louisiana Sunday night. The exact path is still in question, but it looks inevitable that it will hit somewhere on  the central Gulf Coast with devastating winds, storm surges and inland flooding.

Louisiana was hit by three hurricanes last year, two of which were quite powerful, and the state hasn't recovered from those. Now it looks like another hurricane disaster is headed their way.  They can't catch a break. 

Current National Hurricane Center forecasts have top winds of 115 mph with storm surges exceeding eight feet in many coastal locations, so this will be a $1 billion plus disaster yet again.  Gulf of Mexico waters are extremely warm, which is jet fuel for hurricanes. 

Ida could even be worse and stronger than the NHC's gloomy prediction.