Flash Flood — Allegheny, Pennsylvania

2011-08-19 · near Sharpsburg, Allegheny, Pennsylvania

Event narrative

A NWS storm survey found that 2.5 inches of rain fell in one hour in a very urbanized 4.8 sq mi watershed just east of downtown Pittsburgh. Severe flash flooding developed on Washington Blvd resulting in four fatalities and up to 15 water rescues. A mother and two daughters were drowned inside a van when it became submerged in approximately 9 ' 10 feet of water. An elderly lady who abandoned her car was apparently swept or fell into an open manhole or catch basin and drowned.

Wider weather episode

A slow moving cold front and a moist unstable airmass combined to produce scattered severe thunderstorms and flash flooding across eastern Ohio and Western Pennsylvania. Flash flooding was deadly in Pittsburgh when approximately 2.5 inches of rain fell in a very urbanized area just east of downtown Pittsburgh on Washington Blvd in just under an hour. This resulted in four fatalities and up to 15 water rescues.

View location on OpenStreetMap → (40.4834, -79.9090)

Source: NOAA Storm Events Database, event_id 334799. Narrative written by the NWS forecast office that issued the report.