Flash Flood Warning 46, NWS Baltimore/Washington

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
128 PM EDT TUE JUN 18 2013

.SYNOPSIS...
A WEAK COLD FRONT WILL REMAIN OVER THE MID ATLANTIC
THROUGH THIS EVENING AS A WEAK LOW MOVES EAST ACROSS THE SOUTHERN
MID-ATLANTIC. HIGH PRESSURE WILL RETURN TO THE AREA
WEDNESDAY....REMAINING OFF THE NORTHERN MID-ATLANTIC SHORE THROUGH
THIS WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HEADLINE UPDATE...FLASH FLOOD WATCH EXPANSION FOR BALT- WASH
METRO...NORTH-CENTRAL VA...AND THE REST OF THE POTOMAC HIGHLANDS
AND SHENANDOAH VALLEY. END TIME REMAINS UNTIL 6PM.

AS OF 17Z...ONE FRONTAL BOUNDARY WAS LIFTING NORTH INTO THE SRN DC
METRO AND ANOTHER WAS OVER THE NRN SHEN VLY TO PHILADELPHIA. SFC LOW
PRESSURE WILL CONTINUE TO DEVELOP AS IT MOVES ACROSS SERN VA
THROUGH THIS EVENING.

SHOWERS AND ISOLATED THUNDERSTORMS...SEVERAL HEAVY...WILL
CONTINUE TO EXPAND NORTHEAST THROUGH THE CWA THIS AFTERNOON.
MARGINAL INSTABILITY...WITH ISOLATED THUNDERSTORMS EXPECTED TO
CONTINUE. THERE IS STILL A WIND THREAT WITH THE ACTIVITY...THOUGH
THE MAIN THREAT IS HEAVY RAIN/FLOODING.

WITH ALL THIS RAIN...MAX TEMPERATURES HAVE BEEN REACHED.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
THE SHORTWAVE WILL THEN MOVE INTO THE AREA LATER THIS AFTN...
COLLECTING AND COMBINING MUCH OF THE ONGOING PRECIP...AND BEGIN TO
MOVE IT OFF THE COAST. AFTER ONLY REACHING THE L80S FOR DAYTIME
HIGHS W/ PLENTY OF CLOUD COVER...PERIODIC RAIN SHOWERS AND A SLOWLY
CHANGING AIRMASS - WE'LL DROP DOWN INTO THE L-M60S FOR OVERNIGHT
LOWS. SOME RESIDUAL SHOWER AND WEAK TSTM ACTIVITY WILL CONTINUE LATE
THIS EVE FROM EARLIER OUTFLOW BOUNDARIES...BUT MOST OF THE AREA WILL
BEGIN TO DRY OUT.

&&

.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
THE OPERATIVE WORD FOR THE XTND PART OF THE FCST WL BE
"SUMMER"...AS IN "SUMMERY TEMPS WL BE ARRIVING ON THE SUMMER
SOLSTICE"...AND THEN RMNG FOR THE FORESEEABLE FUTURE. LOW PRES WL
BE EXITING THE CST WED MRNG W/ HIGH PRES BLDG IN FM THE UPR
MIDWEST. VERY PLSNT DAYS/NGTS XPCTD WED AND THU W/ HIGHS IN THE
L80S..LOWS RANGING FM THE M50S IN THE HIGHLANDS TO THE M60S IN THE
CITIES.

FRI - THE SOLSTICE. HIGH WL BE MOVG OFF THE CST...HUMIDITY WL
BEGIN TO INCRS. HIGH TEMPS IN THE M80S. SRN RDG WL REALLY BEGIN TO
IMPACT THE MID ATLC THIS WKND. HIGH TEMPS XPCTD TO BE IN U80S/L90S
SAT THRU NEXT TUE. ONLY TSTM CHCS WL LKLY SET UP OVR THE MTNS IN
THE AFTN. WHETHER THESE THEN MOVE E IN THE LATE AFTN/EARLY EVE
WE'LL HV TO WAIT TO SEE.

&&

.AVIATION /17Z TUESDAY THROUGH SATURDAY/...
MOD-HVY RAINFALL SHRA AND ISO TSRA FOR AT LEAST MVFR CONDITIONS.
FRONTAL BOUNDARY WILL PERSIST REST OF THE AFTERNOON BEFORE SINKING
SOUTH OF THE TERMINALS THIS EVENING AS A LIGHT RAIN DEVELOPS.
MUCH OF THE ACTIVITY WILL WANE DURING THE EVENING HOURS AS A WAVE
OF LOW PRESSURE MOVES OFF THE COAST.

IN THE XTND...VFR CONDS XPCTD.

&&

.MARINE...
WEAK GRADIENT OVER THE WATERS TODAY WILL KEEP WINDS BELOW SCA
THRESHOLDS. SHOWERS THUNDERSTORMS WILL PRODUCE STRONG GUSTY
WINDS. NORTH WINDS OCCUR BEHIND THE FRONT TONIGHT BUT ARE EXPECTED
TO ALSO REMAIN BELOW SCA.

WINDS XPCTD TO RMN BLO SCA VALUES IN THE XTND.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FLASH FLOOD WATCH UNTIL 6 PM EDT THIS EVENING FOR DCZ001.
MD...FLASH FLOOD WATCH UNTIL 6 PM EDT THIS EVENING FOR MDZ007-
     009>011-013-014-016-018-501-502.
VA...FLASH FLOOD WATCH UNTIL 6 PM EDT THIS EVENING FOR VAZ025>031-
     036>040-042-050>056-501>504.
WV...FLASH FLOOD WATCH UNTIL 6 PM EDT THIS EVENING FOR WVZ050>053-
     055-501>506.
MARINE...NONE.

&&

UPDATE...JACKSON
PREVIOUS...BPP/GMS/ABW

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1256 PM EDT TUE JUN 18 2013

ANZ530>543-DCZ001-MDZ006-007-011-013-014-016>018-VAZ052>057-
191000-
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-
1256 PM EDT TUE JUN 18 2013

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...THIS AFTERNOON AND TONIGHT

A FLASH FLOOD WATCH IS IN EFFECT UNTIL 6PM FOR THE OUTLOOK AREA
EXCEPT FOR KING GEORGE AND ST MARYS COUNTIES. A FEW THUNDERSTORMS
MAY ALSO PRODUCE LOCALLY DAMAGING WIND GUSTS INTO THE EVENING
HOURS.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. PLEASE RELAY
REPORTS OF HEAVY RAINFALL AND FLOODING TO THE NATIONAL WEATHER
SERVICE.

MDZ003>005-009-010-501-502-VAZ025>031-036>040-042-050-051-501>504-
WVZ050>053-055-501>506-191000-
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-
1256 PM EDT TUE JUN 18 2013

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...THIS AFTERNOON AND TONIGHT

A FLASH FLOOD WATCH IS IN EFFECT UNTIL 6PM FOR THE OUTLOOK AREA
EXCEPT FOR A FEW COUNTIES ALONG THE MASON-DIXON LINE. A FEW
THUNDERSTORMS MAY ALSO PRODUCE LOCALLY DAMAGING WIND GUSTS INTO
THE EVENING HOURS.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. PLEASE RELAY
REPORTS OF HEAVY RAINFALL AND FLOODING TO THE NATIONAL WEATHER
SERVICE.

JACKSON