Thunderstorm Wind in Crawford County, Pennsylvania

Trees downed along South Norrisville Road in Hayfield Township.

Northwest PA resided in the warm and relatively-moist sector during the late morning through early evening of the 7th. Simultaneously, a surface low moved generally eastward from the Straits of Mackinac to near northern Georgian Bay as the trailing cold front moved eastward from the Lake Michigan region to Lake Huron, southeastern Lower MI, far-northwest OH, and northeastern IN. Within the warm sector, scattered multicell thunderstorms developed along an eastward-moving surface trough axis and persisted generally east-northeastward across northwest PA during the early through mid-afternoon hours of the 7th. The storms' ambient environment exhibited weak to moderate MUCAPE and moderate to strong effective bulk shear. One of the multicell thunderstorms generated isolated straight-line wind damage on the east side of Harmonsburg in Crawford County.