Scary Cloud Was Not Tornadic, But People Were Right To Be Scared

Nora Kinney took this photo of a scary looking cloud
Friday evening during the severe weather. The National
Weather Service says this cloud was almost certainly
a downburst, a destruction rush of air crashing
downward from a thunderstor. 

After Friday's severe weather outbreak in Vermont and surrounding states, Nora Kinney shared on social media the photo you see in this post. It's an apocalyptic looking cloud as viewed from Essex looking toward Colchester as thunderstorms approached.

As you can see, it's pretty scary, this sort of bell shaped black thing appearing to lower toward the ground. Was it tornadic? After all, we were under a tornado watch at the time.

I wasn't 100 percent sure, so I put the question to the National Weather Service office in South Burlington. They got back to me right away with an answer. Nope. Nothing tornadic. But it something potentially dangerous.  

First that sort of bumpy cloud at the top of that cloud mass that appears to tilt upward to the left is a shelf cloud, which the NWS told me is "the leading edge of rain cooled air associated with thunderstorm outflow."

Shelf clouds are pretty common on the leading edge of thunderstorms, especially storms that are on the strong side, or severe.

That big dark thing that curves a bit outward like a bell is a downburst. You usually don't see them this well defined because they're often obscured by lighter rain out ahead of it.

A downburst is a very strong downdraft in a thunderstorm that can cause a lot of damage, which is why you should pretty much be as scared of a downdraft as you would be in a tornado. They're often mistaken for a tornado because people sometimes here that "freight train" sound as a downburst approahes.

A downburst usually causes wind damage in only a two mile area or so. They usually last 15 minutes or less, but can cause winds of up to 160 mph, and in rare cases even more than that. Downbursts are more common than tornadoes, probably happening ten times as frequently as tornadoes.

As I said, downburst are dangerous. When the National Weather Service thinks one will happen, they'll issue a severe thunderstorm warning. Downbursts are one reason why you should take a severe thunderstorm warning as seriously as a tornado warning. Severe thunderstorms can be very dangerous, too.

A severe thunderstorm warning from the National Weather Service in South Burlington was in effect when Kinney took the photo.

Pine tree against a house, and pine branches on the roof of this Shelburne,
Vermont house after Friday's destructive thunderstorm downburst there. 

The photo Kinney snapped probably happened at the same time a neighborhood in Colchester was being blasted by damaging winds.

The wind associated with this downburst was estimated at 80 mph. It took part of the roof off one home, knocked over quite a few trees, and sent a couch that had been sitting on a back deck flying, according to television station WPTZ.

And, typical of most downbursts, it was just one small area that was affected. Most of the rest of Colchester had little or no thunderstorm damage.

There was many downbursts with Friday's severe weather, which explains the widespread reports of damage. The destruction from the storms I talked about the other day in Shelburne was almost certainly caused by a downburst, for example.

So yeah, quite an interesting Friday evening in Vermont, from a weather, cloud and meterological standpoint.

WIld Friday: Lots Of Damage But (Probably) No Tornado

Phew!

The storms of Friday are done, but they sure caused havoc.

Stormy skies Friday evening looking north along Route 105 toward
Sheldon, Vermont

There were multiple reports of wind damage, hail, flash flooding and other bad stuff Friday, but despite the tornado watches and a weather setup that was the most favorable for Vermont tornadoes in years, I don't think there were any twisters.

The National Weather Service in Burlington, Vermont might go out to assess some of the  hardest hit areas to see if there were any embedded tornadoes in the severe storms.

It's possible there were, but most of the damage - based on early reports - suggests straight line winds.

The Burlington National Weather Service office has not issued a tornado warning in  nearly four years, and got through Friday without issuing one. But they did issue many severe thunderstorm warnings, for good reason.

As always in severe weather outbreaks, it was very hit and miss. Burlington got pretty much a run of the mill thunderstorm, while Shelburne, just to the south, was blasted.

Lots of downed trees in Shelburne, Vermont after Friday's storm. 

Dozens, if not hundreds of trees blew down in and near Shelburne village.

The roof of at least one home along Route 7 was damaged. Windows were also blown out of that house.

Authorities closed Route 7 near Shelburne Museum, and  many other Shelburne roads were blocked or partly blocked by fallen trees or branches. Flash flooding in Shelburne added to the chaos.

Reports of damage came from all over Vermont and New York. Multiple trees fell in towns like Brookfield, Pittsford, Ascutney, Thetford, Manchester, Danby and Colchester. Golf ball sized hail pelted Richford. Although I'm not aware of any tornadoes, there was evidence that some storms were rotating.

Green Mountain Power reported up to 20,000 homes and businesses without electricity Friday night.

I spotted what appeared to be a wannabe wall cloud slowly spinning west of St. Albans on the southwest side of a thunderstorm. Wall clouds sometime lead to tornadoes, but if this was a wall cloud, it definitely did not produce a twister.   .

This low hanging cloud slowly rotated on the southwest side of
a thunderstorm over St. Albans Friday evening. This was NOT a
funnel cloud, but the fact that it was spinning indicated rotation
in some of the thunderstorms over Vermont Frdiay. 

When that cloud came over the St. Albans - Sheldon town line, a dark piece of scud cloud hung low from the cloud, slowly rotating. It was not a funnel cloud, but it was still interesting to watch.

Rotation was observed, either in the clouds or on radar, in storms near Enosburg Falls and near Manchester. I'm interested in the Manchester storm because radar hinted at a possible tornado north of that town.

Some of the storms dropped two inches or more of rain, especially along a path along the Winooski River Valley and up into the Northeast Kingdom. Flash flooding hit parts of West Bolton and Jericho.

Up in Westmore, a landslide came down the steep slopes of the mountains surrounding Lake Willoughby, causing flooding in the south end of the lake.

I don't have details on that event yet, but it will be interesting to find out if the landslide caused a min-tsunami on the lake, or just blocked the path of some water, backing it up and causing flooding.

I do know the landslide blocked Route 5A.

Even after the thunderstorms moved on, the chaos wasn't done. Strong winds developed behind the squall line, especially over northern New York. Winds gusted to 79 mph in Malone and 68 mph at Cumberland Head, near Plattsburgh. Shingles blew off the roof of at least one home in Plattsburgh.

All in all quite a day.

It will be so, so much quieter today. It will be a perfect day to do some gardening if your town wasn't hit hard by the storms, or a good day for cleanup if your town was blasted by severe storms.

Under quite a bit of sunshine temperatures will get well into the 60s today.

A cold front will come through Sunday afternoon and night with some showers, but nothing wild like on Friday. After a somewhat chilly Monday, most of the upcoming week still looks quite lovely with sunshine and temperatures in the 60s to low 70s.