From the NWS:
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1213 PM EDT THU MAY 31 2007…A FEW SEVERE THUNDERSTORMS ARE EXPECTED THIS AFTERNOON…
HOT AND HUMID CONDITIONS HAVE DEVELOPED ACROSS THE REGION TODAY.
THE AIRMASS HAS BECOME VERY UNSTABLE…ESPECIALLY ACROSS THE
SHENANDOAH VALLEY…CENTRAL VIRGINIA AND AREAS ADJACENT TO THE
BLUE RIDGE. SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP THIS
AFTERNOON AND A FEW OF THOSE STORMS ARE EXPECTED TO BECOME SEVERE.SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE HIGHER
TERRAIN ALONG AND WEST OF THE BLUE RIDGE MOUNTAINS BETWEEN NOON
AND 2 PM. ANY THUNDERSTORMS THAT DEVELOP TODAY WILL BE VERY SLOW
MOVING AND PRODUCE VERY HEAVY RAINFALL IN A FEW LOCATIONS. THE
MOST LIKELY AREA FOR SEVERE STORMS IS ALONG AND WEST OF A LINE
FROM NEAR CHARLOTTESVILLE VIRGINIA TO FREDERICK MARYLAND. THE
STRONGEST ACTIVITY IS EXPECTED TO REMAIN WEST OF THE METROPOLITAN
AREAS TODAY. THE STRONGEST ACTIVITY WOULD BE EXPECTED BETWEEN 2
AND 6 PM TODAY. THE PRIMARY RISK FROM ANY SEVERE THUNDERSTORMS
WOULD BE DAMAGING WIND GUSTS.
