Aug 13, 2018
A lingering upper level low pressure system drifting across Pennsylvania promoted low convective temperatures, allowing numerous showers and thunderstorms to develop, which concentrated near disturbances around the upper low. Decent instability and strong low-level lapse rates promoted damaging wind gusts and hail. Moisture overall was not excessive for August, but thanks to weak flow near the upper low, storm motion was generally 10 knots or less. This promoted a few instances of flash flood
Source: NOAA National Weather Service Storm Events Database (event 779964). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Westmoreland County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.