Severe storms were moving south and west of the Baltimore area Wednesday evening, expected to bring threats of hail, damaging winds and isolated tornadoes.
A tornado watch has been issued for Allegany, Carroll, Charles, Frederick, Garrett, Howard, Montgomery, Prince George's and Washington, D.C. until 9 p.m. A special weather statement cautions of severe weather in Anne Arundel, Baltimore and Harford counties and Baltimore City.
Severe thunderstorm warnings were issued across central and northern Virginia on Wednesday afternoon, and a tornado warning was issued in south central Pennsylvania, north of Cumberland.
All of Maryland west of the Chesapeake Bay was in an area with an elevated risk of severe weather, according to the Storm Prediction Center in College Park. The sun's heat was expected to build atmospheric instability over the region, with a stalled front over the region and a burst of atmospheric energy expected to pass through.
"As a matter of fact, daytime heating, a northbound warm front, and upper level energy pushing in from the west poses a threat of bringing strong to severe thunderstorms to our region midday through the evening hours Wednesday," National Weather Service forecasters wrote on Facebook. The storm forecasting center suggests those conditions could be conducive to development of what are known as supercells, storm systems associated with tornadoes and damaging downward winds.
Damaging winds and large hail are the primary risks with the system, but there is also a threat of isolated tornadoes, according to the center. Forecasters estimated a 15 percent chance of severe winds and hail over Maryland, and a 5 percent chance of tornadoes.