A moist low-level atmosphere and an upper-level trough over the western Great Lakes combined to produce very unstable conditions across the region. Convection formed along a lake breeze boundary southeast of Lake Michigan.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS IWX wrote it up.
Synopsis for May 17th...A moist low-level atmosphere and an upper-level trough over the western Great Lakes combined to produce very unstable conditions across the region. Convection formed along a lake breeze boundary southeast of Lake Michigan. With the numerous outflow boundaries from earlier convection the thunderstorms continued to move east throughout the evening.
The Northern Indiana radar (KIWX), 98 km away, was scanning. The volume nearest the first event began at 21:32 UTC.
5 thunderstorm wind, 3 hail. Local standard time, as filed.
Trees reported blown down. Paudling County sheriff reported 70 mph thunderstorm wind gust.
County EMA reported roof torn off of building and an old building destroyed by straight-line winds.
NWS spotter reported 1 1/2 inch diameter hail in Oakwood.
Trees and power lines reported down countywide.
Power lines blown down.
Utility poles and power lines blown down.
Three-quarter inch hail reported by NWS spotter at Swanton.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Ohio in 1999Every state in 1999This day in weather historyWarnings in Ohio, May 1999
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5696141, 5696142, 5696143, 5696144, 5696145, 5696146, 5696147, 5696148.