Flash Flood Warning 47, NWS Baltimore/Washington

052 
WGUS71 KLWX 080039
FFSLWX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
839 PM EDT TUE AUG 7 2012

VAC015-790-080049-
/O.CAN.KLWX.FF.W.0047.000000T0000Z-120808T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CITY OF STAUNTON VA-AUGUSTA VA-
839 PM EDT TUE AUG 7 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR CENTRAL AUGUSTA AND
CITY OF STAUNTON COUNTIES...

RAIN HAS MOVED OUT OF THE WARNED AREA...THEREFORE THE FLASH FLOOD
WARNING HAS BEEN CANCELLED.

LAT...LON 3822 7915 3825 7899 3811 7894 3809 7911

$$

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
331 PM EDT TUE AUG 7 2012

.SYNOPSIS...
WEAK HIGH PRESSURE WILL REMAIN OFF THE COAST MIDWEEK...PERMITTING
SOUTHWEST FLOW TO BECOME ESTABLISHED. A COLD FRONT WILL ARRIVE LATE
FRIDAY INTO SATURDAY.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
18Z SFC ANALYSIS SHOWS THE CENTER OF HIPRES HAS SHIFTED OFF THE
MID-ATLANTIC COAST. REMNANT SFC DEWPOINT BOUNDARY STRETCHING FROM
THE NRN PIEDMONT TO JUST SE OF I-95. THIS BOUNDARY WILL REMAIN
NEARLY STATIONARY THIS AFTN. DEWPOINTS IN THE LOW AND MID 60S RESIDE
NORTH AND WEST OF THE BOUNDARY...LOWER 70S TO THE SOUTH AND EAST.
BLENDED SAT AND RAP ANALYSIS SHOWED A TIGHT NW TO SE PWAT
GRADIENT...RANGING FROM UNDER INCH OVER THE ALLEGHENY FRONT TO JUST
UNDER TWO INCHES OVER THE SRN MD CHSPK BAY.

SCT SHOWERS AND TSTMS HAVE DEVELOPED ERY THIS AFTN SOUTH AND EAST OF
DC. EXPECT AN UPTICK IN THE ACTIVITY MID AFTN IN THIS MOIST/UNSTABLE
AIRMASS ALONG AND SOUTH/EAST OF THE BOUNDARY...WHERE MID-LVL LIFT IS
LOCATED AHEAD OF A WEAK SHORTWAVE TROUGH MOVING THRU SRN MD.

WITH LIGHT WINDS ALOFT...STORM MOTION WILL BE VERY WEAK. THE
SETUP SUPPORTS A LOCALIZED THREAT OF FLASH FLOODING IN THE NRN
PIEDMONT AND SRN MD. STILL CANNOT RULE OUT A PULSE SEVERE STORM OR
TWO GIVEN THE FAVORABLE ENVIRONMENT FOR A WET MICROBURST...
ALTHOUGH CLOUD COVER HAS LIMITED THE THREAT.

LGT SLY FLOW WILL OVERTAKE ENTIRE REGION TNGT AS HIPRES MOVES AWAY
FROM THE ERN SEABOARD. SIMILAR TO LAST NGT...CONVECTION WILL WANE
AFTER SUNSET...BUT A COUPLE OF SHOWERS AND STORMS MAY LINGER
OVNGT...ESPECIALLY IN SRN MD. ANOTHER MUGGY NGT IS EXPECTED WITH
MIN TEMPS IN THE 60S WELL NORTH AND WEST OF THE DC AND
BALTIMORE...LOW 70S IN THE NEARBY SUBURBS AND MID 70S IN THE CITIES.

THE DIFFUSE BOUNDARY WILL REMAIN OVER THE REGION WED...BUT SHOULD
START TO PROGRESS NWD. SHOWERS AND STORMS EXPECTED TO DEVELOP AGAIN
IN THE WARM/MOIST AIRMASS...ESPECIALLY EAST OF THE BLUE RIDGE. GIVEN
LACK OF SYNOPTIC LIFT... COVERAGE SHOULD BE ISO.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AN UPPER-LEVEL TROUGH WILL APPROACH THE CWA DURING THE SECOND HALF
OF THE WORK WEEK. THIS WILL PRODUCE SHOWERS AND THUNDERSTORMS...SOME
OF WHICH COULD BE SEVERE...BOTH THURS AND FRI AFTERNOONS. CONTINUING
SOUTHWEST FLOW INTO THE AREA WILL MAINTAIN A WARM HUMID AIRMASS
THROUGH MIDWEEK. THIS COMBINED WITH THE PASSAGE OF A SHORTWAVE PRIOR
TO THE MAIN UPPER-TROUGH WILL PROVIDE SUFFICIENT LIFT FOR TSTMS
THURS AFTERNOON. BY FRI...A COLD FRONT LOOKS TO BE POSITIONED JUST
TO THE REGION/S WEST WITH ANOTHER WIDER SPREAD ROUND OF SEVERE
WEATHER IN THE AFTERNOON HOURS. BOTH DAYS HAVE BEEN OUTLOOKED BY SPC
WITH A SLIGHT RISK FOR THE CWA DURING DAYS 3 AND 4.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
GUIDANCE DEPICTS THE ACTUAL FRONT TRANSITIONING ACROSS THE AREA
DURING THE DAY SATURDAY WITH HIGH PRESSURE BUILDING IN BEHIND. THIS
WILL LOWER TEMPS BY 5-10 DEGREES TO VALUES A LITTLE COOLER THEN
NORMAL FOR THE BEGINNING OF AUGUST. PRECIP COULD LINGER THROUGH THE
DAY SATURDAY AS THE FRONT SLOWLY MOVES OFFSHORE. HOWEVER...THE
THREAT OF SEVERE STORMS WILL BE CONFINED TO THURS AND FRI. WIND WILL
SHIFT TO NORTHWEST BRINGING DRIER AIR INTO THE REGION FOR THE
BEGINNING OF THE WEEK. EXPECT MOSTLY DRY CONDITIONS WITH DAYTIME
HIGHS IN THE MID 80S AND LOWS IN THE MID 60S FOR SUN THROUGH TUE.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
MVFR AND IFR VSBYS ARE EXPECTED ACROSS AREA TERMINALS TONIGHT AS A
HUMID AIR MASS REMAINS OVER THE REGION. CHO SHOULD SEE THE BIGGEST
DROP IN VSBY AS THE AREA COULD SEE SOME SCATTERED SHOWERS AND
THUNDERSTORMS THIS AFTERNOON. ELSEWHERE WITH THE EXCEPTION OF
DCA...SHOULD SEE REDUCTIONS TO AROUND 3 SM. WIND WILL SLOWLY SHIFT
FROM NORTHEAST TO SOUTHWEST THROUGH THE TAF VALID PERIOD. THE
SOUTHWESTERLY SHIFT IN WIND DIRECTION WILL HELP TO MAINTAIN LOW
LEVEL BUT VFR CIGS THROUGH THE DAY TOMORROW.

AN UPPER LOW WILL DEEPEN OVER THE UPPER MIDWEST AND GREAT LAKES LATE
THIS WEEK WHILE AN ASSOCIATED COLD FRONT MOVES THRU FRI NGT OR SAT.
UNSETTLED WX WILL OCCUR DURING THIS TIME...WITH HIGH CHANCES FOR
PRECIP THU-SAT. SOME STORMS MAY BE STRONG DURING THE AFTN HRS THU
AND FRI. VSBY RESTRICTIONS IN STORMS LIKELY.

&&

.MARINE...
A RESIDUAL BOUNDARY REMAINS STATIONARY OVER THE CENTRAL MD CHSPK
BAY....WITH SLY FLOW OCCURRING SOUTH OF NORTH BEACH AND NELY FLOW TO
THE NORTH. THE BOUNDARY WILL SLOWLY LIFT NWD WED. ENHANCED SLY FLOW
DUE TO CHANNELING SOUTH OF THE BOUNDARY WILL STILL REMAIN BELOW SCA
THRESHOLD THRU WED. ISO SHOWERS AND STORMS  MAY LINGER INTO THE
NGT...THOUGH NOT AS STRONG AND WIDESPREAD AS THIS AFTN. THREAT OF
STORMS CONTINUE WED.

LOPRES AND ASSOCIATED COLD FRONT WILL APPROACH FROM THE WEST THU
BEFORE MOVING THRU FRI AND SAT...RESULTING IN A PROLONGED PERIOD OF
SHOWERS AND STORMS DURING THIS TIME. SOME OF THE STORMS MAY BE
STRONG THU AND FRI AFTN.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

KLEIN/CLS

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1010 AM EDT TUE AUG 7 2012

ANZ530>543-DCZ001-MDZ006-007-011-013-014-016>018-VAZ052>057-
081000-
CHESAPEAKE BAY NORTH OF POOLES ISLAND MD-
CHESAPEAKE BAY FROM POOLES ISLAND TO SANDY POINT MD-
CHESAPEAKE BAY FROM SANDY POINT TO NORTH BEACH MD-
CHESAPEAKE BAY FROM NORTH BEACH TO DRUM POINT MD-
CHESAPEAKE BAY FROM DRUM POINT MD TO SMITH POINT VA-
TIDAL POTOMAC FROM KEY BRIDGE TO INDIAN HEAD MD-
TIDAL POTOMAC FROM INDIAN HEAD TO COBB ISLAND MD-
TIDAL POTOMAC FROM COBB ISLAND MD TO SMITH POINT VA-
PATAPSCO RIVER INCLUDING BALTIMORE HARBOR-
CHESTER RIVER TO QUEENSTOWN MD-EASTERN BAY-
CHOPTANK RIVER TO CAMBRIDGE MD AND THE LITTLE CHOPTANK RIVER-
PATUXENT RIVER TO BROOMES ISLAND MD-
TANGIER SOUND AND THE INLAND WATERS SURROUNDING BLOODSWORTH
ISLAND-DISTRICT OF COLUMBIA-NORTHERN BALTIMORE-HARFORD-
SOUTHERN BALTIMORE-PRINCE GEORGES-ANNE ARUNDEL-CHARLES-ST. MARYS-
CALVERT-PRINCE WILLIAM/MANASSAS/MANASSAS PARK-FAIRFAX-
ARLINGTON/FALLS CHURCH/ALEXANDRIA-STAFFORD-SPOTSYLVANIA-
KING GEORGE-
1010 AM EDT TUE AUG 7 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE MARYLAND PORTION OF THE
CHESAPEAKE BAY...TIDAL POTOMAC RIVER...AND ADJACENT COUNTIES IN
CENTRAL MARYLAND AND NORTHERN VIRGINIA AS WELL AS THE DISTRICT OF
COLUMBIA.

.DAY ONE...TODAY AND TONIGHT

ONE OR TWO THUNDERSTORMS IN SOUTHERN MARYLAND AND CENTRAL VIRGINIA
MAY PRODUCE LOCALLY DAMAGING WINDS THIS AFTERNOON. THE STORMS WILL
BE SLOW-MOVING AND COULD PRODUCE HEAVY RAINFALL...WHICH MAY LEAD
TO VERY LOCALIZED FLASH FLOODING.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP ON THURSDAY AND
NUMEROUS THUNDERSTORMS ARE EXPECTED ON FRIDAY. SOME OF THESE
THUNDERSTORMS MAY BE SEVERE...CAPABLE OF PRODUCING DAMAGING WIND
GUSTS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED ON THURSDAY AND FRIDAY...MAINLY
DURING THE AFTERNOON AND EVENING HOURS.

MDZ003>005-009-010-501-502-VAZ025>031-036>040-042-050-051-501>504-
WVZ050>053-055-501>506-081000-
WASHINGTON-FREDERICK MD-CARROLL-MONTGOMERY-HOWARD-
EXTREME WESTERN ALLEGANY-CENTRAL AND EASTERN ALLEGANY-AUGUSTA-
ROCKINGHAM-SHENANDOAH-FREDERICK VA-PAGE-WARREN-CLARKE-NELSON-
ALBEMARLE-GREENE-MADISON-RAPPAHANNOCK-LOUDOUN-ORANGE-CULPEPER-
NORTHERN FAUQUIER-SOUTHERN FAUQUIER-WESTERN HIGHLAND-
EASTERN HIGHLAND-HAMPSHIRE-MORGAN-BERKELEY-JEFFERSON-HARDY-
WESTERN GRANT-EASTERN GRANT-WESTERN MINERAL-EASTERN MINERAL-
WESTERN PENDLETON-EASTERN PENDLETON-
1010 AM EDT TUE AUG 7 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN WEST VIRGINIA...
NORTHERN AND CENTRAL VIRGINIA...AND CENTRAL AND WESTERN MARYLAND
WITH THE EXCEPTION OF GARRETT COUNTY.

.DAY ONE...TODAY AND TONIGHT

ONE OR TWO THUNDERSTORMS IN CENTRAL VIRGINIA MAY PRODUCE LOCALLY
DAMAGING WINDS THIS AFTERNOON. THE STORMS WILL BE SLOW-MOVING AND
COULD PRODUCE HEAVY RAINFALL...WHICH MAY LEAD TO VERY LOCALIZED
FLASH FLOODING.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP ON THURSDAY AND
NUMEROUS THUNDERSTORMS ARE EXPECTED ON FRIDAY. SOME OF THESE
THUNDERSTORMS MAY BE SEVERE...CAPABLE OF PRODUCING DAMAGING WIND
GUSTS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED ON THURSDAY AND FRIDAY...MAINLY
DURING THE AFTERNOON AND EVENING HOURS.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
611 PM EDT TUE AUG 07 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0555 PM     TORNADO          1 ENE BENEDICT          38.51N  76.67W
08/07/2012                   CALVERT            MD   FIRE DEPT/RESCUE

            WATERSPOUT MOVING WEST IN PATUXENT RIVER NEAR BENEDICT
            BRIDGE.

&&

EVENT NUMBER LWX1201042

SBK

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
721 PM EDT TUE AUG 7 2012

VAZ025-072345-
AUGUSTA VA-
721 PM EDT TUE AUG 7 2012

...STRONG THUNDERSTORM TO AFFECT AUGUSTA COUNTY...

AT 721 PM EDT...A STRONG THUNDERSTORM WAS LOCATED OVER STAUNTON...
MOVING SOUTHEAST AT 10 MPH.

LOCATIONS IMPACTED INCLUDE WAYNESBORO AND LYNDHURST.

WIND GUSTS OF 40 TO 50 MPH CAN BE EXPECTED WITH THIS STORM.

&&

LAT...LON 3795 7897 3816 7920 3829 7904 3812 7878
      3811 7878 3810 7879
TIME...MOT...LOC 2321Z 314DEG 9KT 3816 7904