Thunderstorm Wind in Erie County, Pennsylvania

Minor roof damage in Corry.

At the surface, a cold front extended southwestward across eastern Lake Erie, northeast OH, and southwest OH, during the early afternoon of the 9th and drifted eastward to near the corner of northeast OH along the border of northwest PA by mid-evening. Ahead of the cold front, multiple clusters of multicell thunderstorms, including bow echoes, persisted generally east-northeastward. These storms generated very isolated straight-line wind damage and two mesovortex-related tornadoes; a weak tornado in Crawford County and a strong tornado in Erie County. The storms traversed an ambient environment comprised of weak MUCAPE, moderate to strong effective bulk shear, favorable mixed layer LCL's less than 1500 meters AGL, and marginally-favorable surface-based ESRH near 100 to 150 meters squared per second squared.