Flash Flood — Allegheny, Pennsylvania

2018-07-02 · near Harmerville, Allegheny, Pennsylvania

Event narrative

The 911 Call Center reported flooded intersection near Squaw Run Road/Field Club Road and at the intersection Fairview Road and Old Mill Road. An emergency manager also reported rushing water near Woodland Farms Road. Fox Chapel Stone Supply INC worker says the store took on 2 ft of water (WPXI reported). Aspinwall declared a state of emergency. The O'Hara Township manager reported that some homes may be total losses; said total infrastructure losses in the township added up to $1.3 million.

Wider weather episode

A line of thunderstorms developed east of Cleveland from a breeze off of Lake Erie near 17Z. Areas south and east of the line gave way to more storms as outflow boundaries converged. With high PWAT values (near 1.90) flash flooding became an issue with training storms.

Wet microbursts were also a concern with DCAPE values near 500kjg-1. The Weather Prediction Center had our region under a slight risk for excessive rainfall.

View location on OpenStreetMap → (40.5458, -79.8683)

Source: NOAA Storm Events Database, event_id 772437. Narrative written by the NWS forecast office that issued the report.