Flash Flood — Seneca, Ohio

2022-08-21 · near Fostoria, Seneca, Ohio

Event narrative

Fostoria Police and Fire reported flash flooding across the southern half of Fostoria. All underpasses in the city were impassable with up to 5 feet of water over the roadways. Most streets on the south side of Fostoria were flooded with an average of 2 feet of water depth. Several reports of vehicles stranded in flood waters with up to 3 feet of water depth. Reports of numerous basements flooded. Trained spotter measured 3.05 inches of rain in around an hour period between 1300 LST to 1400 LST. Radar estimates of 2.5 to 3 inches of rain fell in this one hour period across Fostoria, with a peak recurrence interval of 50 years where the heaviest rain fell. Peak instantaneous rainfall rates of 3.5 inches per hour were estimated by radar.

Wider weather episode

Weak surface low pressure slowly moved across northwest Ohio over the southern shore of Lake Erie in north central Ohio during the afternoon and evening hours of August 21st. A warm front was oriented from west to east across the area just south of the lakeshore, while a trailing cold front slowly advanced eastward behind the low. In the warm sector, MUCAPE values of 1000-1500 j/kg, weak deep layer shear, and precipitable water values of 1.6 to 1.7 inches allowed for deep moist convection to develop with heavy rainfall. Upwind propagation vectors were generally out of the southwest at 10 kts or less, promoting slow storm movement with enhanced training potential. Several clusters of storms trained over urban areas in north central Ohio causing localized urban flash flooding as rainfall rates as high as 4 to 5 inches per hour tracked over residential areas.

View location on OpenStreetMap → (41.1538, -83.4209)

Source: NOAA Storm Events Database, event_id 1055286. Narrative written by the NWS forecast office that issued the report.