Multiple Rounds of Severe Weather
for the Miami Valley in Early May
Severe thunderstorms developed in an unstable airmass over Illinois and Indiana during the afternoon of May 3. Even though these thunderstorms encountered a dry and more stable airmass over Ohio, the dry air near the ground allowed for cold and strong downdrafts as they moved into the Miami Valley, which resulted in several reports of wind gusts over 60 mph. Scattered reports of wind damage were received, including some structural damage in Darke County.
On Wednesday May 5, a cold front dropped in from the north, sparking off a few thunderstorms across northern portions of the Miami Valley. These storms produced large hail across far northern Hardin County, and gave other parts of the Miami Valley a good lightning show.
A more potent system moved into the Ohio Valley on Friday, May 7. Numerous severe thunderstorms developed across northern portions of Indiana and Ohio. Further south across western and central Ohio, a more stable airmass prevented a widespread severe thunderstorm event. However, one severe thunderstorm developed over eastern Indiana and remained severe as it moved into areas northwest of Columbus. Once again, Darke County was hit with severe winds causing damage to multiple structures.
PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE WILMINGTON OH
154 PM EDT SAT MAY 8 2010
...STORM DAMAGE SURVEY COMPLETED FOR DARKE AND MIAMI COUNTIES...
A NATIONAL WEATHER SERVICE STORM SURVEY COMPLETED SATURDAY MORNING
DETERMINED THAT THE DAMAGE REPORTED ACROSS DARKE AND MIAMI
COUNTIES FROM THUNDERSTORMS FRIDAY EVENING MAY 7TH WERE THE RESULT OF
STRAIGHT LINE WINDS AND NOT A TORNADO.
ANALYSIS OF THE DAMAGE...WHICH INCLUDED NUMEROUS DOWNED TREES AND
SEVERAL BARNS WHICH WERE DESTROYED...AND REPORTS FROM SPOTTERS IN
THE AREA CONFIRMED THAT THE DAMAGE FIT THE CHARACTERISTICS OF THAT
CAUSED BY STRAIGHT LINE WINDS. IN ADDITION...RADAR DATA FROM THE
NATIONAL WEATHER SERVICE IN WILMINGTON SHOWED NO INDICATION OF
SIGNIFICANT ROTATION WITHIN THE THUNDERSTORM.
THE STORMS MOVING IN EXCESS OF 60 MPH...COUPLED WITH AN
ENVIRONMENT SUPPORTIVE OF SIGNIFICANT WIND GUSTS...LIKELY WERE THE
MAIN CONTRIBUTORS TO THE PATH OF WIND DAMAGE SURVEYED SATURDAY
MORNING. BASED ON THE DAMAGE AND RADAR DATA...WINDS WERE ESTIMATED
TO BE AROUND 70 MPH.
THE MOST CONCENTRATED AREA OF DAMAGE EXISTED ALONG A LINE FROM
NEW MADISON AND ARCANUM IN DARKE COUNTY...INTO AREAS FROM PLEASANT
HILL TO TROY IN MIAMI COUNTY. THIS DAMAGE LIKELY OCCURRED
BETWEEN 840 PM AND 915 PM FRIDAY EVENING.