An isolated tornado or two could develop through this evening, but damaging winds and hail are more likely hazards, the NWS says.
From the NWS:
PRIMARY THREATS INCLUDE... A COUPLE TORNADOES POSSIBLE SCATTERED LARGE HAIL AND ISOLATED VERY LARGE HAIL EVENTS TO 2 INCHES IN DIAMETER POSSIBLE SCATTERED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE SUMMARY...THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER NORTHERN VA AND WESTERN MD THIS AFTERNOON...TRACKING ACROSS THE WATCH AREA. DAMAGING WINDS AND HAIL ARE THE MAIN THREATS. HOWEVER...BACKED LOW LEVEL WINDS NEAR A WARM FRONT MAY BE SUFFICIENT TO ENHANCE THE RISK OF ISOLATED TORNADOES OVER NORTHERN PARTS OF THE WATCH. THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 90 STATUTE MILES EAST AND WEST OF A LINE FROM 30 MILES EAST SOUTHEAST OF CHARLOTTESVILLE VIRGINIA TO 25 MILES NORTH OF HARRISBURG PENNSYLVANIA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE WARNINGS.
Original story: The National Weather Service has issued a Severe Weather Outlook for Northern Virginia Monday afternoon and evening.
The NWS says there could be severe storms that feature hail and there may be isolated tornadoes.
As of Monday at noon, the forecast said there was an enhances storm risk. A 2 percent chance of a tornado within 25 miles, and a 30 percent chance of hail and damaging winds more than 55 miles per hour.
The risk could increase later on Monday, says the Capital Weather Gang.
The storm risk will begin at 5 p.m. and run until 10 p.m. Monday.