EF1 tornado in Westmoreland County, Pennsylvania

A brief EF1 tornado occurred southwest of Ligonier. This tornado was part of the same parent circulation that generated the tornado near Donegal and Bear Rocks. The primary damage was to trees, with numerous snapped and uprooted pines and maples noted by the survey team along Darlington Road, Fairview School Road, and Weller Road, with a concentration of 20-30 trees affected between Fairview School and Weller Road. The tornado dissipated near Two Mile Run Road.

A strongly forced band of convection developed over West Virginia in the morning ahead of an approaching front, and quickly lifted north-northeastward into Pennsylvania through the early afternoon. Despite relatively modest instability, very strong deep layer shear, along with largely unidirectional southerly flow and elongated hodographs, supported the continuation of significant severe storms. Large impact was felt from straight-line wind, with gusts in the 60 to 80 MPH range, locally higher, causing widespread damage to trees, power lines, and structures. The line of storms continued into Pennsylvania, where the environment was more favorable for tornadic development. In addition to damaging winds, a number of large hail reports were received, with some stones as large as 1.75 inch diameter. Also, embedded supercells/mesovortices produced five confirmed tornadoes during the afternoon (one of which crossed from Fayette County into Westmoreland County).