Thunderstorm Wind in Mifflin County, Pennsylvania

A severe thunderstorm producing winds estimated near 60 mph knocked down trees in multiple locations west of Lewistown.

Scattered showers and thunderstorms develop during the early afternoon hours of July 17, 2021 across western Pennsylvania and in the Lower Susquehanna Valley in an anomalously humid airmass ahead of an approaching cold front. The storms over the Lower Susquehanna Valley developed on a weak boundary in a high CAPE environment, and produced sporadic wind damage before moving to the east. The storms over western Pennsylvania eventually congealed into a broken line that progressed eastward across central Pennsylvania and had imbedded regions of damaging winds and very heavy rain. One hail report was received from beneath a particularly tall cell that developed over Blue Mountain just west of Marysville in Perry County. Flash flooding from these storms was reported across McKean, Dauphin and Tioga Counties.