SOUTHERN MARYLAND — Numerous thunderstorms are expected across Southern Maryland Thursday afternoon and evening, with damaging wind gusts possible and storms potentially lingering into the late evening, according to the National Weather Service.
The National Weather Service Baltimore/Washington office said thunderstorms are expected to become numerous between about 3 p.m. and 9 p.m. Thursday, Aug. 20. Charles, Calvert and St. Mary’s counties are included in a Hazardous Weather Outlook issued at 6:50 a.m.
Some of the storms could produce damaging wind gusts. The Weather Service also said a couple of tornadoes are possible within the broader forecast area, although the greatest tornado concern is expected near northeast Maryland.
Southern Maryland is not identified as the area facing the greatest tornado threat, but residents should remain alert as thunderstorms move through the region and conditions change during the afternoon and evening.
The Weather Service also identified a threat of urban flash flooding. The highest flash-flood risk is expected near and northeast of Baltimore rather than Southern Maryland.
Storms could remain active across Southern Maryland after the primary 3 p.m. to 9 p.m. period.
“Storms may linger over southern Maryland through late evening,” the Weather Service said in the outlook.
The timing could affect the evening commute, outdoor activities and travel on local waterways. Thunderstorms may develop quickly and could bring periods of heavy rain, strong winds and lightning as they cross the region.
The outlook covers a large portion of Maryland, northern Virginia and the District of Columbia, along with extensive areas of the Chesapeake Bay and tidal Potomac River.
Southern Maryland waterways included in the outlook include the Chesapeake Bay from North Beach to Drum Point and from Drum Point to Smith Point, the tidal Potomac River from Indian Head to Cobb Island and from Cobb Island to Smith Point, and the Patuxent River to Broomes Island.
The Weather Service said Special Marine Warnings will likely be needed Thursday afternoon and evening as thunderstorms move across the waters.
Boaters and others planning to be on the Chesapeake Bay, Potomac River, Patuxent River or nearby waterways should closely monitor changing weather conditions before and during the storm period.
Thunderstorms over open water can create rapidly changing conditions, particularly when strong winds accompany a storm. The Weather Service’s statement that Special Marine Warnings will likely be required signals that marine conditions could become hazardous as storms move through the region.
The outlook also includes Tangier Sound and the inland waters surrounding Bloodsworth Island, the Choptank River to Cambridge and the Little Choptank River.
The forecast comes as the Weather Service monitors a broad area stretching from Southern Maryland north through the Baltimore region and into Cecil County, as well as parts of Northern Virginia.
While Southern Maryland is included in the broader severe-weather threat, the outlook distinguishes where some hazards are expected to be greatest. The greatest tornado concern is near northeast Maryland, while the highest urban flash-flood risk is near and northeast of Baltimore.
For Charles, Calvert and St. Mary’s counties, damaging winds and thunderstorms during the afternoon and evening remain the primary concerns identified in the outlook.
Residents should continue monitoring National Weather Service forecasts and any watches or warnings issued as storms develop.
A Hazardous Weather Outlook provides advance notice of weather that could become dangerous but is different from a severe thunderstorm warning, tornado warning or flash flood warning. More specific alerts may be issued as storms develop and forecasters determine where the greatest threats are occurring.
Conditions can vary significantly from one part of Southern Maryland to another during thunderstorms. Some communities may receive only a brief period of rain and wind, while others could experience stronger thunderstorms or repeated rounds of rain.
The main period for thunderstorms remains approximately 3 p.m. to 9 p.m. Thursday, with the possibility that storms could continue across Southern Maryland into the late evening.
Residents traveling Thursday afternoon or evening should be prepared for rapidly changing weather and should check updated forecasts before leaving, particularly if their plans involve outdoor activities or travel on the water.
The National Weather Service outlook covers both Thursday and Thursday night, meaning the threat will not necessarily end with the evening commute.
Additional watches, warnings or advisories could be issued as conditions develop throughout the day.
