Today’s cover photo shows a snapped power pole in Huntsville from Tuesday’s storm. In addition, the viewer who posted it describes the scene: “Hwy 30 - 45 intersection Huntsville. The collision center collapsed with people in it, Jack n box is on fire (or was), lots of trees down, several bad wrecks. 1) Power out at the West Hills Mall. 2) Power pole down on the 11st bridge. Lines laying across the road. 3) Tree down northbound on 75. 4) Power out at Napa are heading Northbound towards 75. 5) Police sirens blazing near normal park. 6) Power lines and trees down at Hobby Lobby and Aldi. 7) Walmart is out of power. 8 ) Trees down on Hickory Drive. 9) Powerlines down outside Wish Wash. 10) Forest Hills, trees are down, and no power. 11) Petco and the strip center is out of power.”
StormTracker2 followed the storm and here it is at 2:35pm:
By 3:20 p.m. the storm was howling through Willis on its way to Panorama Village:
And at 3:40 p.m. was through Conroe, where a collapsed home under construction left two fatalities and seven injuries:
The National Weather Service investigated Wednesday and determined that this was a “microburst” wind event. In essence, straight line winds to 80 mph which, according to senior meteorologist Sean Luchs, “is roughly on par with the wind speeds seen in an EF-0 tornado (of course, the two are different events in that the twisting winds of a tornado are more chaotic, while straight line winds tend to encompass a wider swath).” You can read the most current report of the storm right here.
So just what IS a microburst? Simply put, downward rushing air. You know that warm air rises and cold air sinks. The warm rising air is what creates the thunderstorm in the first place. Dry air around the storm plays a key role (and there was plenty of it -- you’ll notice above that this was a lone single storm surrounded by dry air). That dry air introduces even colder air into the storm and so when that sinking cold air hits even colder air it accelerates! When the air hits the ground it bursts outward in almost all directions, the way water does when you point a hose at the driveway.
People have said this storm ‘came out of nowhere’ and it certainly seemed to although given the heat of the day and different wind directions from Low pressure to the north and high pressure to the south, it’s easy to go back and see how the storm materialized. And THE reason that the Stormtracker2 Weather Team is always watching and always tracking! You have to keep on it!
By the way, I’ve had more than a few viewers ask why First Day of Summer is already on my 10-day forecast, like Bruce B:
I get it -- astronomical summer begins June 21 in accordance with the sun’s position relative to the equator. That’s what we all grew up with. Meteorological summer is June-July-August for easier climate data and record keeping. And, well, I am a meteorologist!
In that vein, have an astronomically awesome Memorial Day weekend!
Frank
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