Tropical Storm — St. Mary's, Maryland

2020-08-04 · St. Mary's, Maryland

Event narrative

Tropical Storm Force winds observed at Patuxent River Naval Air Station ASOS (KNHK) with sustained winds of 40 mph at 8:04 AM EST, and a peak wind gust of 58 mph at 9:12 AM EST. Also observed at St. Indigoes MD ASOS (KNUI) with sustained winds of 30 mph at 7:53 AM EST, and a peak wind gust of 52 mph at 8:35 AM EST. Dozens of reports of trees down in a few areas as a result of these winds, one of which fell onto a vehicle in motion, killing the motorist. There was also an EF-0 tornado near Scotland, MD and an EF-1 tornado near Piney Point, MD.

Wider weather episode

Tropical Storm Isaias moved up the east coast, passing through southern Maryland on the morning of Tuesday, August 4th, 2020, spawning several tornadoes as well as flooding rain and tropical storm force winds.

Storm total rainfall ranged from 2 to 4 inches near Interstate 95 to as much as 9 inches in Calvert County east of Interstate 95. The heavy rain led to numerous incidents of flooding and flash flooding, especially near and east of Interstate 95.

The highest sustained wind of 46 knots was reported at Bishops Head and the highest peak gust of 63 knots was also reported at Bishops Head.

There were three tornadoes associated with Isaias over southern Maryland and there were also numerous reports of downed trees from tropical storm force winds, especially near and east of Interstate 95.

A storm surge of 1 to 2 feet occurred along the western shore of the Chesapeake Bay and the shore of the Tidal Potomac River. This did result in minor tidal Flooding in Washington DC.

Source: NOAA Storm Events Database, event_id 918700. Narrative written by the NWS forecast office that issued the report.