Could a microburst do this?

[MJ Poore]

I was investigating what appears to be a tornado touchdown this week. It killed one and injured 400 people. It was the strangest damage I have ever seen. It was a kilometer wide swath of light destruction that went on for about 4km - amid the path, a roof taken off in one place, but all around other roofs ok. Then a tree down, while other trees around it undamaged. I get the feeling this was a very wide F1 event. But it's got me thinking about microbursts, could these be involved as well? The question is just how much damage can a burst do? Observe the two damage pics attached below? I'd be interested to know what others, who might have seen this sort of thing before, think? Notice how everything around the damaged bits seems to be untouched. Could this be long exposure type damage, considering it appears to be a kilometer wide, but the tornadic winds were relatively light? The metal roofing wrapped around the lampole makes me think this was a tornado. The collapsed concrete wall you see was steel reinforced into the ground.

 

[Ray Walker]

Well a severe wind gust strong enough to blow a peace of sheet metal of a building could easily do what happened in the picture. All that happed from what im lookin at is the wind blew the sheet metal off the roof of a barn or building and the metal hit the pole at a high speed and wraped around the pole. Also the way the fence is laying tells me wind from either a microburst or severe gust blew it down.

 

[Esa Tuunanen]

Down/microburst can easily shred away roofing sheets... or whole roof if sheets are fixed too well. And that's exactly what would happen to sheet flying in air and its mid point hitting hard obstacle. Such sheet offers huge area (compared to strength) for wind to fold it.


Also very sharp edges of destruction area aren't any problem, two years ago one storm made two consequent 10x50 meters strips and hundred meters later there was around 50m size oblong hole in forest little right from line of previous strips. Inside those there wasn't single tree standing while few meters away trees were practically untouched. 5km later it had again picked up in power and made half hectare "final felling".


Here's very good examples of downburst damages:

http://www.myrskyharrastajat.fi/main.site?action=binary/file&id=2&fid=231
http://www.myrskyharrastajat.fi/main.site?action=binary/file&id=2&fid=241
http://www.myrskyharrastajat.fi/main.site?action=binary/file&id=2&fid=239
http://www.myrskyharrastajat.fi/main.site?action=binary/file&id=2&fid=224
http://www.myrskyharrastajat.fi/main.site?action=siteupdate/view&id=114

http://www.helsinki.fi/~ajpunkka/galleria.htm (storm damages)

 

[Joel Wright]

I suppose it could be possible it was a combination of a EF0/EF1 tornado and a strong RFD. Without seeing it all in person, and lack of radar data it's sort of a shot in the dark.

 

[David Drummond]

Downbusts often create very tornado-like damage. Most of the time everything is layed out in a radial pattern from the center of the downburst, but sometimes you can get diverging patterns in the damage if wind is diverted around a strong structure that doesn't give.

I've seen entire buildings destroyed out here in west Texas by downbursts and plenty have been injured.

 

[fplowman]

I wish I remember where i saw the video of a downburst happening.. It was like an atomic bomb.. Awesome!

 

[jason kissam]

When I was in Missouri at college we had a tornado warning one day and they said it hit by the race track in town. Well being in video production class I grabbed a camera. we found damage similar to all the pics. A mobile home sales lot was hit flipping entire doublewides on their lids. The official report was a microburst / downdraft occurance. No tornado was sighted either.

Here in Colorado we had a plane crash into a park some years back. The FAA and the NTSB were stumped to what brought the plane into a severe nosedive and lead it to crash. They studied the winds and found an interesting pattern of down draft activity around the colorado springs airport and I believe in denver too.

 

[fplowman]

Yeah Jason, Any storm that would create a downburst like the damage shown will be prolific and show up easily on radar. I seen a video once of a storm very well defined just drop its whole load at once like the snap of your fingers it dropped tons of rain and energy right on top of the area below.

Im always amazed at how the winds aloft can suspend baseball hail and tons of rain. With the microburst it all collapses at once.. Its crazy!!!

 

[Shane Hale]

I would agree with the rest... I have heard of microburst haveing in excess of 100 mph winds... one thing I have learned is, is the damage in an out going pattern in such a manner to resemble the path water would follow if poured down on the ground. If the damage is converging then you have more of tornadic damage.

 

[Gerrit Gulden]

Im pretty sure it was just a microburst with those severe straightline winds. With the fence basically laying in place and not being scrambed and the Sheetmetal bended along the pole is good enough evidence of a straightline wind event or Microburst. There would have been a little more damage done with an EF0 and more widespread debris.


-gerrit

 

[MJ Poore]

Thanks for all the replies. It does look to me as well like strong burst. I don't have the photos, but at the centre of the damage track there seemed to be a pattern of rotation with more concertrated damaged, ie roofs torn off and shipping containers pushed along. Some signs of missile damage as well. The opinion of meteorologists who looked at the path was that it was a combination of burst and tornado. There was big hail and strong rain at the time as well. It's strange when these things are combined, both straightline and apparently, rotation, in one event. That's what it appears to be at least. I have never encountered anything like it before.