Hail and Damaging Winds in Ohio, July 21, 1998

Synoptic and mesoscale conditions for July 21st...A stationary front draped across southern Lake Michigan into northern Ohio began to shift slowly southwardduring the 21st. A weak shortwave trough would interact with this boundary by late afternoon producing another outbreak of severe thunderstorms. Capes the afternoon of the 21st exceeded 5000 J/kg thanks in part to surface dewpoints in the mid 70s and mid level cold air advection under the approaching mid level shortwave. An east-west line of multicellular severe thunderstorms quickly developed along the front by late afternoon. As the convectively generated cold pool deepened... a large outflow boundary developed and began to spread southward generating new convection along the leading edge. Very heavy rain fell within this line of storms as they pushed slowly south as evidenced by reported rainfall amounts. Many locations experienced wet microbursts within the stronger multicell storms. Freezing level temperatures and wet bulb zero temperatures were quit high which greatly inhibited large hail formation. The convective outflow weakened later that evening with echo training developing across central Indiana which went on to produce widespread flash flooding during the morning of July 22nd.