Thunderstorm Wind — Adams, Pennsylvania

2022-07-02 · near Round Top, Adams, Pennsylvania

Event narrative

A severe thunderstorm producing winds estimated near 60 mph knocked down trees onto wires along Knight Road south of Gettysburg.

Wider weather episode

As an upper trough moved eastward into New England on July 2, 2022, the eastern half of Pennsylvania remained in the right entrance region of the trough, promoting weak ascent in the atmosphere. A cold front slowly moved southeastward across Pennsylvania, with a prefrontal trough over the lower Susquehanna Valley acting as a primary trigger for afternoon convection. Several discrete and multicell thunderstorms developed within a narrow corridor around the prefrontal trough, in an environment with 2000 J/kg CAPE and up to 1200 J/kg of DCAPE. Deep layer 0-6 km shear of up to 35 kts combined with the instability to promote briefly rotating updrafts with transient supercell characteristics for at least one thunderstorm, which produced ping pong ball size hail. There were also several reports of damaging straight line winds associated with downbursts.

View location on OpenStreetMap → (39.7769, -77.2430)

Source: NOAA Storm Events Database, event_id 1029269. Narrative written by the NWS forecast office that issued the report.