Thunderstorm Wind in Clarion County, Pennsylvania

Trees were reported to be blown down in Rimersburg.

Deep upper level low pressure moved into the western Great Lakes on November 20th. A strong shortwave rotating around this upper low across Ohio helped to drive a cold front across the Upper Ohio Valley during the late afternoon hours. A thin line of showers accompanied the front, with little to no lightning. The front worked with sufficient instability aloft to bring strong wind gusts to the surface, with several in the 45 to 60 MPH range according to various observations. These gusts were responsible for the many reports of wind damage received across southwest Pennsylvania. Strong low-level shear and weakly veered wind profiles also supported a brief tornado on the north side of Pittsburgh.