7/13/10: Flash Flood Watch

NORTHERN BALTIMORE-HARFORD-MONTGOMERY-HOWARD-SOUTHERN BALTIMORE-PRINCE GEORGES-ANNE ARUNDEL-PRINCE WILLIAM/MANASSAS/MANASSAS PARK-FAIRFAX-ARLINGTON/FALLS CHURCH/ALEXANDRIA-

INCLUDING THE CITIES OF…WASHINGTON…GAITHERSBURG…COLUMBIA…BALTIMORE…ANNAPOLIS…MANASSAS…MANASSAS PARK…FAIRFAX…ALEXANDRIA…FALLS CHURCH
221 PM EDT TUE JUL 13 2010

..FLASH FLOOD WATCH IN EFFECT FROM 6 PM EDT THIS EVENING THROUGH LATE TONIGHT…

THE NATIONAL WEATHER SERVICE IN STERLING VIRGINIA HAS ISSUED A

* FLASH FLOOD WATCH FOR PORTIONS OF THE BALTIMORE AND WASHINGTON METROPOLITAN AREAS FROM 6 PM THIS EVENING THROUGH LATE TONIGHT.

* AN UPPER-LEVEL DISTURBANCE WILL MOVE ACROSS THE MID ATLANTIC REGION LATE TONIGHT AND INTO THE OVERNIGHT HOURS. SHOWERS AND THUNDERSTORMS WILL PRODUCE LOCALLY HEAVY RAINFALL ACROSS THE AREA. RAINFALL RATES OVER ONE INCH PER HOUR ARE POSSIBLE IN HEAVIER SHOWERS AND THUNDERSTORMS. THE BEST CHANCE FOR THE HEAVIER PRECIPITATION WILL BE OVERNIGHT.

* ONE HOUR FLASH FLOOD GUIDANCE IS BELOW TWO INCHES AND SIX HOUR FLASH FLOOD GUIDANCE REMAINS BELOW THREE INCHES ACROSS PORTIONS OF THE AREA DUE TO RECENT RAINFALL. AVERAGE RAINFALL AMOUNTS BETWEEN ONE AND TWO INCHES ARE EXPECTED…BUT RAINFALL AMOUNTS OVER THREE INCHES ARE POSSIBLE IN HEAVIER SHOWERS AND THUNDERSTORMS.


PRECAUTIONARY/PREPAREDNESS ACTIONS…

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.

YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION SHOULD FLASH FLOOD WARNINGS BE ISSUED.