Jul 28, 2012
Strong instability and deep moisture combined with a vigorous upper-level disturbance over the Lower Great Lakes and weak frontal boundary/inverted lee trough east of the Blue Ridge Mountains to produce isolated severe thunderstorms and localized heavy rainfall during the late afternoon and early evening hours. Slow steering motions aloft allowed thunderstorms to remain nearly stationary and produce flash flooding in the Williamsport area.
Source: NOAA National Weather Service Storm Events Database (event 386979). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Lycoming County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.