Last Week's Austin, Texas Storm Super Wild, Super Weird

From Facebook, photo of damage at Austin Wildlife
Rescue after the massive supercell and oxymoronically
named large microburst in the city last week. 

 Texas is known for its, well, Texas sized storms.

But even by those standards, what hit the Austin, Texas area was absolutely wild.  I guess the "Keep Austin Weird" slogan applies to the weather there as well. 

A fast developing, giant supercell roared over the city on May 28.   It almost, but didn't quite produce a tornado. But it might as well have, given the damage it caused. There were also no other storms around it, just an isolated, big, bad one, Very bad,

It produces  one of the worst microbursts, one of the heaviest rainfall rates and some of the worst hail to ever hit Texas, and maybe the United States for that matter. 

MICROBURST

As the name implies, microbursts hit a relatively small area.  On average, they'll do their damage in a one to two mile diameter area. 

Microbursts, as noted,  are often are as dangerous as tornadoes, as the storm in Austin demonstrates.  Some microbursts carry wind gusts of 100 mph, which is the equivalent of an EF-1 tornado. (For comparison the tornado that hit in Middlebury, Vermont, in March, 2021, seriously damaging one home and causing lighter damage to several others, was an EF-1

The National Weather Service explains what causes these dangerous thunderstorm microbursts.:

Strong updrafts suspend a bunch water droplets in the upper portion of the storm. At some point, the updraft is no longer able to sustain all that stuff, so it lets them go like a clumsy waiter dropping a tray load of dishes. 

When the "tray load of dishes" hits the ground, all hell breaks loose, like it did in Austin, writ large.

The Austin area microburst, despite its name, was pretty huge.  

The damage path was about ten miles long, with a path ranging from one to 2.5 miles wide. Maximum sustained winds within the microburst were probably between 65 mph and 85 mph, with a few embedded higher gusts. The Austin-Bergstrom International Airport had a 77 mph gusts, reports KXAN.

REAR FLANK DOWNDRAFT

To make matters worse, the supercell had something called a rear flank downdraft in which winds reached up to 75 mph.  As KXAN reports:

The National Weather Service mapped out damage
from the May 28 supercell and big microburst.
Area in red is damage from the microburst, yellow
is from a real flank downdraft. The darker
the color, the worse the damage was.

"A rear flank downdraft is caused by pressure patterns within a supercell thunderstorm that force cool mid-level winds quickly down to the ground before getting pulled back into the rotating thunderstorm."

Rear flank downdrafts are common in in supercells, especially strong ones like that in and around Austin last week.

Like the microburst, the rear flank downdraft moved southeastward, in tandem with the microburst that was just to the north and east of the rear flank downdraft.

This downdraft and its 75 mph wind blew right through downtown Austin.  

DAMAGE

The wind, as you'd imagine, knocked down a lot of trees and power lines. About 180,000 residents lost power.  Winds of that speed tend not to seriously damage well-constructed homes, but it was enough to tear shingles off roofs and break windows  I'm sure several homes and other buildings suffered damage from falling trees

Windows and doors were reported broken by the wind at Austin-Bergstrom airport and the Texas State Capitol building in Austin. The canopy over gas pumps at an Austin service station collapsed onto cars beneath it whose owners were taking shelter from the hail. Thankfully, only minor injuries were reported. 

The largest oak tree in Austin's first Black cemetery toppled over and damaged several headstones.

The wind drove large hailstones sideways, damaging the siding on countless homes, Roofs, crops, trees and gardens were also blasted and wrecked.  

Intense flash flooding swept cars off roads and left at least one person dead. At least five others had to be rescued from submerged cars.

 The spot where the microburst first hits the ground is usually where the worst damage is.  In Austin's case, there might have been a train of microbursts, one after another. Or, the supercell thunderstorm that caused it had much more rain and hail to unload than most storms. 

It was also a single thunderstorm and not a line. While all hell was breaking loose on the north side of Austin and its suburbs, it was a pleasant evening with sunshine in the southern end of Austin.

Austin is weird. 

VIDEOS

Compilation of some of the storm scenes in Austin: As always, click on this link to view, or if you see the image below, click on that,

More images, mostly of the flooding from the microburst last week in Austin: Again, click on this link to view, or if you see image below click on that,