High pressure resided across the east coast while a warm front was located across the Carolinas. Moist air continued to move into the Mid Atlantic as showers intensified ahead of the warm front.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS LWX wrote it up.
High pressure resided across the east coast while a warm front was located across the Carolinas. Moist air continued to move into the Mid Atlantic as showers intensified ahead of the warm front. Heavy rain produced flooding in parts of the Washington DC and Baltimore Metro Areas.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Baltimore/Washington wrote its last area forecast discussion before the first event at Aug 12, 11:22 AM EST, 23 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1222 PM EDT TUE AUG 12 2014
.SYNOPSIS...
LOW PRESSURE IS CENTERED OVER OHIO WITH A WARM FRONT EXTENDING
INTO THE CAROLINAS AND A COLD FRONT STRETCHING TO WEST TENNESSEE.
THE COLD FRONT WILL CROSS THE AREA EARLY WEDNESDAY MORNING. HIGH
PRESSURE WILL RETURN FOR THE SECOND HALF OF THE WEEK AND INTO THE
WEEKEND.
&&
.NEAR TERM /UNTIL 9 PM THIS EVENING/...
SYNOPTIC PTTN HAS CHGD LTL SINCE ELY THIS MRNG. HIGH PRESSURE
REMAINED OFF THE NEW ENGLAND/MID ATLC COASTS THIS MRNG...ALLOWING
A MOIST SOUTHEAST FLOW ACROSS THE CWA. MEANWHILE...FRONTAL
BOUNDARY OVER THE CAROLINAS WAS SNAKING ITS WAY BACK UP THE
APPALACHIANS AND INTO LOW PRESSURE OVER THE LOWER GREAT LAKES.
TO THE NORTH OF THIS BOUNDARY...ISENTROPIC LIFT/OVERRUNNING MOISTURE
WAS PRODUCING WAVES OF SHOWERS ACROSS THE REGION AS SHOWN BY
REGIONAL MOSAIC RADAR. A MORE SOLID ROUND OF SHRA ACRS CWFA ATTM
WITHIN A CONVEYOR OF HIGH PRECIPITABLE WATER/HIGH THETA-E AIR.
HIGH PW/S PROMOTING HEAVY RAINFALL ATTM. FFG RATHER HIGH FOR MOST
AREAS...BUT RAINFALL RATES HIGH AS WELL. CELLS HV BEEN TRAINING...
AND RADAR HAS BEEN UNDERESTIMATING THREAT. FLASH FLOOD WATCH HAS
BEEN POSTED FOR I-95 CRRDR WHERE GROUND HAS BEEN PRIMED.
SINCE PLUME OF RAFL HAS BEEN PERSISTENT...ITS INHIBITING CNVCTV
THREAT. STILL CANT RULE OUT EMBEDDED LOW-TOPPED TSRA...WHICH CUD
RESEMBLE TROPICAL CHARACTERISTICS. DMGG WND THREAT STILL NON-ZERO.
BOTH GFS AND NAM SUGGEST A WAVE OF LOW PRESSURE ALONG THE FRONT THIS
EVENING...WHICH WOULD TEND TO SLOW DOWN ITS EASTWARD PROGRESS. THUS
CONVECTION MAY CONTINUE WELL INTO THE EVENING. BUT EVENTUALLY THE
COLD FRONT WILL MOVE THROUGH AND WEST/NORTHWEST WINDS BEHIND THE
FRONT WILL PROMOTE DRYING AND A DECREASING TREND IN POPS OVERNIGHT.
FCST TEMPS MATCH UP WELL W/ LAMP...AND NO CHGS ANTICIPATED. TODAY/S
MAXIMA WERE DERIVED FROM A BLEND OF BIAS CORRECTED SREFS/ADJMAV...
FAVORING BELOW NORMAL UNDER CLOUDS/FREQUENT SHOWERS AND SOUTHEAST
FLOW. ADJMET HAS PERFORMED VERY WELL LATELY AND WAS USED FOR
MINIMA.
&&
.SHORT TERM /9 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
CWA WILL BE POST-FRONTAL WEDNESDAY...BUT UPPER TROUGH AXIS STILL HAS
TO PASS THROUGH. THIS COMBINED WITH COOLER AIR ALOFT WILL RESULT IN
SOME CLOUDS BUT CWA SHOULD BE DRY SAVE FOR A FEW SHOWERS ACROSS THE
POTOMAC HIGHLANDS...MAINLY THE WESTERNS SLOPES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
WE HV A VERY COMPLEX NEXT 36 HRS IN THE MID ATLC...BUT AFTR THAT
THINGS SHOULD BE CALMING DOWN NICELY. THE CD FNT SHOLD BE WELL E
OF THE AREA WED NGT. A PRES GRAD COULD PERSIST WED NGT KEEPING IT
BRZY...OR DECOUPLING COULD OCCUR AND WINDS GO LGT. OUTSIDE OF THE
CITIES/ALONG THE BAY LOWS WL BE IN THE 50S WED NGT.
NO PROBS FORESEEN THU/FRI OR INTO THE WKND. HIGH PRES OVR THE
AREA. XPCT TO SEE A GRADUAL WARMUP: L80S TO END THE WORKWK THEN
CLIMBING INTO THE MU80S SUN.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
ROUND OF SHRA W/ MDT-BRIEF HVY RA CROSSING METROS ATTM. MADE SOME
ADJUSTMENTS FOR BRIEF IFR.
AFTER A RELATIVE LULL...THUNDERSTORMS THEN ARE POSSIBLE THIS
AFTERNOON/EARLY EVENING AND ADDRESSED WITH VCTS IN THE TAFS. FRONT
WILL MOVE THROUGH OVERNIGHT WITH A WIND SHIFT TO WEST/NORTHWEST.
THIS SHOULD PRECLUDE FOG FORMATION OVERNIGHT. VFR EXPECTED
WEDNESDAY.
VFR CONDS XPCTD WED NGT STRAIGHT THRU TO THE WKND.
&&
.MARINE...
SE FLOW BCMG SLY TDA. HV NMRS SITES AT OR NEAR SCA CRIT ATTM...AND
WNDS PROGGED TO INCR. SCA IN EFFECT ALL WATERS REST OF TDA.
DVLPG THUNDERSTORMS LATER THIS AFTERNOON/EVENING COULD ALSO PRODUCE
STRONG GUSTY WINDS. ANTICIPATE SOME SPECIAL MARINE WRNGS MAY NEED
TO BE ISSUED.
COLD FRONT MOVES THROUGH OVERNIGHT. NOT SURE HOW STRONG THE NW
PUSH IS BEHIND THE FRONT FOR WEDNESDAY. CAN/T RULE OUT A SCA
BECOMING NECESSARY BUT CONFIDENCE TOO LOW ATTM.
IN THE XTND PD...PRIMARILY A CALM PD ON THE WATERS. IT IS PSBLTHAT
SCA LVL GUSTS MAY CONT ON THE BAY...BUT THU AND FRI LOOKING LK
GOOD DAYS TO BE ON THE WATERS. AS OF NOW THIS TREND IS XPCTD TO
CONT INTO THE WKND.
&&
.TIDES/COASTAL FLOODING...
ANOMALIES REMAIN AROUND 1 FT AS OF 8AM. WITH SOUTHEAST FLOW THIS
MORNING...THEN SOUTHERLY FLOW THIS AFTERNOON ANOMALIES MAY
INCREASE TODAY. SO EVEN THOUGH THE PM TIDE IS A LITTLE LOWER
ASTRONOMICALLY...SUSPECT THE RESULTS WILL BE ABOUT THE SAME. IN
ADDITION...CBOFS WATER LEVEL ANIMATION SUGGESTS WATER WILL PILE
AROUND THE MOUTH OF THE SUSQUEHANNA AS WELL...SO HAVRE DE GRACE
SHOULD SEE SOME IMPACTS BY TONIGHT. WITH THIS IN MIND...HAVE
EXTENDED ADVY TO INCLUDE THE AFTN/EVE TIDE CYCLE. PRINCE GEORGES
CNTY HAS BEEN ADDED BASED ON SURVEY WORK. ANY INUNDATION WOULD BE
HIGHLY LOCALIZED NUSAINCE/MINOR.
BLOWOUT NWLY WINDS WILL BE ARRIVING AT THE SAME TIME AS THE AM
TIDE CYCLE. IT WILL BE A CLOSE CALL. AT THIS POINT...CANNOT RULE
OUT A FEW SITES BEING AFFECTED ONE MORE TIME ELY WED MORNING...
MAINLY ANNAPOLIS SOUTH.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR DCZ001.
COASTAL FLOOD ADVISORY UNTIL 2 AM EDT WEDNESDAY FOR DCZ001.
MD...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR MDZ005>007-009>011-
013-014-016.
COASTAL FLOOD ADVISORY UNTIL 2 AM EDT WEDNESDAY FOR MDZ007-011-
013.
COASTAL FLOOD ADVISORY UNTIL 10 PM EDT THIS EVENING FOR MDZ014-
017-018.
VA...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR VAZ052>057.
COASTAL FLOOD ADVISORY UNTIL 2 AM EDT WEDNESDAY FOR VAZ054.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ532>534-
537-540>543.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ530-
531-535-536-538-539.
&&
SYNOPSIS...
NEAR TERM...HTS/BPP
SHORT TERM...BPP
LONG TERM...WOODY!
AVIATION...HTS/BPP/WOODY!
MARINE...HTS/BPP/WOODY!
TIDES/COASTAL FLOODING...HTSHAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1216 PM EDT TUE AUG 12 2014 ANZ530>543-DCZ001-MDZ006-007-011-013-014-016>018-VAZ052>057- 130930- 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- 1216 PM EDT TUE AUG 12 2014 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 LATE TONIGHT FOR PORTIONS OF MARYLAND...THE DISTRICT OF COLUMBIA AND VIRGINIA. PERIODS OF SHOWERS AND THUNDERSTORMS WITH AREAS OF HEAVY RAINFALL WILL BE POSSIBLE WHICH MAY RESULT IN POTENTIAL FLOODING ALONG THE INTERSTATE 95 CORRIDOR. SOME THUNDERSTORMS DURING THE LATE AFTERNOON AND EVENING MAY ALSO PRODUCE DAMAGING WIND GUSTS. AN ISOLATED TORNADO IS ALSO POSSIBLE. A COASTAL FLOOD ADVISORY IS IN EFFECT FOR THE WESTERN SHORE OF THE MARYLAND CHESAPEAKE BAY AND ALONG THE UPPER TIDAL POTOMAC RIVER THROUGH THE HIGH TIDE CYCLE THIS AFTERNOON AND EVENING. TIDAL FLOODING MAY LINGER INTO PREDAWN WEDNESDAY MORNING FOR SAINT MARYS...CALVERT...AND ANNE ARUNDEL COUNTIES. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE MARYLAND CHESAPEAKE BAY AND TIDAL POTOMAC RIVER TODAY. THE SMALL CRAFT ADVISORY CONTINUES OVER A PORTION OF THE WATERS THIS EVENING. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY A SMALL CRAFT ADVISORY MAY BE NECESSARY OVER A PORTION OF THE WATERS WEDNESDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EVENING. MDZ003>005-009-010-501-502-VAZ025>031-036>040-042-050-051-501>504- WVZ050>053-055-501>506-130930- 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- 1216 PM EDT TUE AUG 12 2014 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 LATE TONIGHT FOR PORTIONS OF MARYLAND...THE DISTRICT OF COLUMBIA AND VIRGINIA. PERIODS OF SHOWERS AND THUNDERSTORMS WITH AREAS OF HEAVY RAINFALL WILL BE POSSIBLE WHICH MAY RESULT IN POTENTIAL FLOODING PRIMARILY EAST OF THE BLUE RIDGE AND ACROSS THE INTERSTATE 95 CORRIDOR. SOME THUNDERSTORMS DURING THE AFTERNOON AND EVENING MAY ALSO PRODUCE DAMAGING WIND GUSTS. AN ISOLATED TORNADO IS ALSO POSSIBLE. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EVENING.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1147 AM EDT TUE AUG 12 2014
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1134 AM FLASH FLOOD 1 SSW CHEVY CHASE VIEW 39.01N 77.09W
08/12/2014 MONTGOMERY MD EMERGENCY MNGR
CEDAR LANE CLOSED BETWEEN BEACH DRIVE AND MD 355 DUE TO
HIGH WATER.
&&
EVENT NUMBER LWX1400914
MEADOWSPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1202 PM EDT TUE AUG 12 2014
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1143 AM FLASH FLOOD 1 N CONGRESSIONAL MANOR 39.01N 77.17W
08/12/2014 MONTGOMERY MD EMERGENCY MNGR
SWIFT WATER RESCUE ON BRADLEY BLVD AND MERCY HOLLOW
LANE
&&
EVENT NUMBER LWX1400915
MEADOWSThe national radar mosaic for the moment the first event began.
5 flood. Local standard time, as filed.
Water from a stream was flowing across Woodburn Road and it was closed.
Fox Mill Road was closed at the intersection with Hunt Road from flooding.
The USGS stream gauge on Accotink Creek exceeded the flood stage of 9.5 feet and flooded Woodburn Road. It reached flood stage at 1828 UTC and crested at 10.34 feet at 2215 UTC. It went below flood stage at 2259 UTC.
There was minor over bank flooding reported in Huntington from Cameron Run. It went above flood stage at 1849 UTC and peaked at 5.78 feet at 1915 UTC. It went below flood stage at 1946 UTC.
The water level gauge in Belle View reached its flood stage of 5.5 feet. It went above flood stage at 1903 UTC and crested at 5.64 feet at 1915 UTC. It went below flood stage at 1926 UTC.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Virginia in 2014Every state in 2014This day in weather historyWarnings in Virginia, August 2014
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 540068, 540069, 540070, 540071, 540072.