WEAU | Eau Claire, Wisconsin | Weather

Eau Claire Windstorm from Thursday May 24th

It's Memorial Day Weekend and while most of us would like to be on the lake listening to the hum of a boat engine, the hum of chainsaws is going to be what a lot of people hear in Eau Claire this weekend.

A strong thunderstorm rolled through Dunn, Eau Claire and Chippewa Counties Thursday afternoon around 4:30. The storm left it's mark, with many spots in the western and northern parts of city with damage. That damage was also seen in Lake Hallie and Chippewa Falls. The worst of the damage was seen in Eau Claire, with numerous large trees and branches snapped or even up-rooted. Carson Park, Lakeview Cemetery and the Chippewa Valley Regional Airport are just a few spots that saw the strongest winds...just take a look at a few of the pictures from the worst of the damage.

So what caused all the damage...was it a tornado or straight line winds? For me the answer is straight line winds and I'll go through what leads me to that conclusion.

1) After driving and looking through the parts hardest hit in Eau Claire, one thing stuck out about all the trees that were damaged. The vast majority of them had fallen to the northeast, which was the direction the storm was moving. The Severe Thunderstorm Warning that was issued for western Eau Claire and Chippewa county said the storm was moving to the northeast at 70 mph!

Here is the text from that warning...

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
CHIPPEWA COUNTY IN WEST CENTRAL WISCONSIN...
SOUTHEASTERN DUNN COUNTY IN WEST CENTRAL WISCONSIN...
WESTERN EAU CLAIRE COUNTY IN WEST CENTRAL WISCONSIN...
NORTHEASTERN PEPIN COUNTY IN WEST CENTRAL WISCONSIN...
* UNTIL 500 PM CDT
* AT 358 PM CDT...RADAR INDICATED A SEVERE THUNDERSTORM...CAPABLE OF PRODUCING QUARTER SIZE HAIL AND DAMAGING WINDS OF 60 MPH. THIS STORM WAS LOCATED 6 MILES WEST OF MONDOVI...AND MOVING NORTHEAST AT 70 MPH.

2) Notice that it was NOT a Tornado Warning. That is because there wasn't a tornadic rotation detected within the storm. Doppler radar out of the Twin Cities at the time height of the storm did not show any signs of rotation.

The Radial Velocities also supports that there was no rotation in the storm, but certainly some strong straight line winds were possible. The core of green returns near Eau Claire indicates that strong winds were being produced by the storm and possibly reaching the surface. Had there of been red returns close to the green, that would have indicated circulation within the storm, but that was not the case.

(Thanks to Duane Wolter III for saving those pictures)

3) The damage swath was fairly wide, about one mile from north to south. For most tornadoes the damage width is only a few hundred yards, but a mile wide swath is more representative of straight line wind damage. The damage path stretched about 10 miles, starting just west of Eau Claire and then reaching all the way to Chippewa Falls.

The National Weather Service out of the Twin Cities did not come out and do a formal evaluation of the storm,(we really wish they would have) so we do not have an official estimation of the wind speeds from them. Normally, the NWS will come out and do damage surveys when widespread damage is reported.

My best estimation is that 70-80 mph straight line winds were the cause of the damage, and I would not be at all be surprised if wind speeds of 100 mph were experienced. Seeing so many of the trees up-rooted and snapped like they were, well it takes strong winds, definitely over 60 mph to do that sort of damage. I spoke with one gentleman who was sitting in his truck near Lakeview Cemetery when the storm hit. He says the winds pushed his truck 4 feet while it was in park and that the strongest winds lasted for about 45 seconds. Just a reminder that it is always safest to be indoors, away from windows and in the lowest part of your house whenever a Severe Thunderstorm or Tornado Warning is issued.


Comments are posted from viewers like you and do not always reflect the views of this station.
powered by Disqus
WEAU 13 NEWS 1907 S. Hastings Way Eau Claire, WI 54701 By Phone: Main Number (715) 835-1313 and (715) 832-3474. Tip Line (715) 839-WEAU - (715) 839-9328 Sports Line (715) 852-1537
Gray Television, Inc. - Copyright © 2002-2014 - Designed by Gray Digital Media - Powered by Clickability 154269515 - weau.com/a?a=154269515