2011-06-14 Norman OK Microburst

A downburst strikes the north side of Norman, OK on 14 June 2011 at about 7:30 p.m. We went up to the North Base near Max Westheimer airport to shoot some time lapse footage of a developing supercell west of town, only to have it drop a microburst that surged southeastward over us. RaXPol was, semi-coincidentally, deployed nearby, and collected data during the event. In less than three minutes, we went from light rain to 70+ mph winds, golf ball-sized hail, and near-zero visibility. The doors of several airplane hangars at Max Westheimer airport blew off, and one disintegrated as it blew across the field in front of us.

We got lucky. Damage on the east side of Norman was reported to have been much, much worse - windows blown out, fences blown down, and chimneys collapsed.

I may have jumped the gun by labeling this a "microburst" when I uploaded my video; evidently NWS is avoiding that terminology until they do a damage survey. The velocity presentation from the Will Rogers TDWR, however, showed a semi-circular gust front surging toward Norman from the storm in question. (Update: On 15 June, NWS designated this event a downburst/microburst, based on damage survey and radar data: http://www.srh.noaa.gov/oun/?n=events-20110614)

http://tornatrix.net/?p=628

The radar in the video is the Rapid-Scan, X-band, Polarimetric, mobile Doppler radar (RaXPol for short.) You can read more about RaXPol here: http://tornatrix.net/?p=54

The "storm chasers" in this video hold M.S. and Ph.D. degrees in meteorology and have nine years' experience (each) in storm research. All know how to conduct themselves safely in and around severe weather.

Category:

Science & Technology

Tags:

• microburst
• wind
• storm
• oklahoma
• radar
• lightning
• thunder
• rain
• weather

[wgb135]

All right guys, your probably right, but it isn't much fun when your stuff gets tore up whether its a "Burst or F1" Excuse my passion, 

[rtanamachi]

@wgb135 - I sympathize with your losses. We had some damage at our house, as well.

Norman, Oklahoma probably has the greatest concentration of tornado-savvy meteorologists in the U.S., over 500 of whom work at the NWC, and many of them suffered property damage in this downburst. If there had been a tornado, you'd think at least one of those 500+ would have noticed. ;-)

[oklahomaisok]

@rtanamachi can a straight wind blow a 5,000 pound air conditioner off of a building...it happened at Walmart.

[rtanamachi]

@oklahomaisok - I talked to a manager at the east Norman WalMart who said they had 3 A/C units, each about 2,000 lbs (comparable to a car) and mounted about 6 inches off the roof surface, that were moved by the winds. He said none were "blown off," but one had to be removed because it was damaged. They probably slid around like air hockey pucks! The winds on the roof may also have been slightly stronger than at the ground because there were fewer trees, buildings, etc. to slow them down.

[wgb135]

At my house...40ft tree on garage, electrical service plus concrete block pulled off wall 50 ft tree uprooted, pole next to house has no bottom.... wind? Yeah Right!

NWS missed it and will never admit it.. federal gov. whatever

[rtanamachi]

@wgb135 - There was no tornado at our location and no tornado vortex signature in the radar data. You can get tornado-like damage in downbursts, but the damage pattern is divergent, not convergent and localized like a tornado.

BTW, NWC offers public tours. You can visit the NWS and ask questions about the damage survey and how the downburst was determined:

nwc dot ou dot edu slash tourdetails dot php

[WhiteLadyEowyn]

Great video, but the random skunk running by after it passes is cracking me up

[natronacounty]

lol the skunk

[HowsaBowsaYowsa]

That skunk is huge.

[hdninjaz]

Loved the skunk running by after the storm passed. You guys were a mile and a half or so west of us. the winds were much worse on 12th street and east of that

[hdninjaz]

Love the random skunk running by after the microburst. You guys were just a mile and a half or so west of my house. the winds were much worse on the east side of norman

[aprokky]

holy crap!

[Wthrman13]

@wgb135 I point out that the NWS *did* have a severe thunderstorm warning for the possibility of strong damaging winds for this storm several minutes before it hit Norman. It's exactly for situations such as these that there are two categories of warnings. Just because a tornado didn't cause the damage doesn't make it any less serious. In cases such as these, it can almost be worse than a tornado (at least a weak one), because the damage can occur over a much larger area.