National Weather Service United States Department of Commerce

Areas of Excessive Rainfall; Watching for Tropical Cyclone Development in the Atlantic

Heavy to excessive rainfall Wednesday may bring areas of flash and urban flooding over portions of the Ohio and Tennessee Valleys. In Arizona and New Mexico, heavy to excessive rainfall from monsoon thunderstorms may bring isolated flash and urban flooding Thursday into Saturday. Two tropical waves in the Atlantic are being monitored for tropical cyclone formation within the next few days. Read More >

May 3-7, 2010
Multiple Rounds of Severe Weather

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.