A frontal boundary moved northward and stalled over the Mid-Atlantic/I-95 corridor overnight. An upper level low approached the region and a upper level jet added to enhanced lift in the region.
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.
A frontal boundary moved northward and stalled over the Mid-Atlantic/I-95 corridor overnight. An upper level low approached the region and a upper level jet added to enhanced lift in the region. Heavy rain caused a lot of flash flooding with amounts up to seven inches in less than 6 hours recorded near Washington Dulles Airport.
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 Jul 11, 8:31 PM EST, 3 hours 59 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 931 PM EDT THU JUL 11 2013 .SYNOPSIS... A COLD FRONT WILL REMAIN STALLED OVER THE DELMARVA PENINSULA AND SOUTHEASTERN VIRGINIA THROUGH THIS WEEKEND. HIGH PRESSURE WILL BUILD WEST FROM THE WESTERN ATLANTIC EARLY NEXT WEEK. && .NEAR TERM /THROUGH FRIDAY/... LTST SFC ANALY DEPICTS A STALLED CDFNT ALONG THE I-95 CRRDR... WHILE HIPRES RESIDES OVER THE GRTLKS. AN ANIMATION OF WATER VAPOR IMGRY SUGGESTS AN UPR LOW ROTATING ABV THE SFC HIGH...ALSO OVER THE GRTLKS. ALTHO CWFA WL BE ON THE NW SIDE OF THE CDFNT...THERE ARE SVRL FACTORS SUPPORTING A ROUND OF SHRA/TSRA OVNGT...AS EVIDENCED BY RECENT RADAR TRENDS. FIRST...HGTS WL BE DROPPING AS THE UPR LOW NEARS. SECONDLY...THE CWFA WL BE W/IN RRQ OF AN UPR JET. ITS ONLY ABT 60-70 KT...BUT IT/S SUFFICIENT TO SUPPORT LIFT. THIRD... BELIEVE THAT THERE ARE/WL BE A CPL WK IMPULSES GLIDING ALONG THE STALLED SFC BNDRY. RECENT HRRR RUNS VERIFYING QUITE NICELY...AS SWRN CWFA FILLING IN W/ PCPN ECHOES. HV ALREADY ADJUSTED DATABASE TO EMPHASIZE THAT AREA FOR THE EVNG HRS. HV ALSO PAINTED THE OVNGT HRS ON THE WET SIDE...W/ LKLY POPS JUST ABT EVERYWHERE AFTER MIDNGT. 00Z RAOBS HINT AT MINIMAL INSTBY W/ A SMALL CAP. WL PLACE MORE WEIGHT ON SHRA...BUT THINK THAT THERE WL BE ENUF ELEVATED INSTBY FOR A FEW RUMBLES TOO. THAT ROUND OF SHRA/STORMS SHUD CLR AREA BY SUNRISE. IN SPITE OF LMTD INSTBY TMRW...THE H5 LOW WL BE CLOSEST TO CWFA DURING THE DAY. WITH THAT IN MIND...COGNIZANT OF THE UPR JET SUPPORT...AND HINTS AT SOME MID LVL OVERRUNNING...THINK THERE SHUD BE A 2ND ROUND OF SHRA /OR MAYBE A STORM/ FRI AFTN. AFTER REDUCING POPS INTO CHC FOR MOST AREAS...HV TAKEN IT BACK UP TO LKLY AGN FOR THE AFTN HRS. ANY CHGS TO TEMPS/DEWPTS WL BE MINIMAL BASED ON LTST LAMP GDNC. && .SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY/... HIGH PRESSURE CONTINUES TO MOVE WESTWARD AND PUSH MOISTURE INTO THE REGION. ROUNDS OF SHOWERS WILL MOVE ACROSS THE MID ATLANTIC INTO SATURDAY. AS THE HIGH MOVES WESTWARD MOISTURE WILL MOVE TO THE MOUNTAINS AND SUBSIDENCE WILL KICK IN OVER AREAS EAST OF THE BLUE RIDGE. EASTERLY FLOW WILL CONTINUE THE BELOW NORMAL TEMP PERIOD. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... IN JULY THE MAJOR WX PROBLEMS WHICH COME TO MIND ARE HIGH HEAT.. SVR STORMS..AND FLSH FLDG. IT APPEARS THAT ALL OF THESE WL BE HELD AT BAY DURG THE XTND PD. IF THE GFS IS TO BE BLVD...THE COMING UPR LVL PATTERN IS SOMEWHAT OF AN ANACHRONISM FOR MID JUL. NRMLY ONE WOULD XPCT TO SEE A SUBTROPICAL HIGH PARKED OFF THE CST BRINGING A STREAM OF WARM MOIST AIR INTO THE MID ALTC WHICH WOULD BRING ABT THE PSBLTY OF AFTN/EVE TSTMS...W/ THE PTNL FOR HEAT INDICES REACHING ADSRY LVL. OVR THE WKND THAT LOW IS SUPPOSED TO TRACK SLOWLY TO THE W AS HIGH PRES CENTERED NEAR LONG ISLAND BUILDS INTO THE MID ALTC. THIS WL KEEP THE NRML MID-JUL TROPICAL CHARACTERISTICS AT BAY - XPCT TO SEE HIGHS IN THE 80S W/ LOWS IN THE L70S E OF I-95...60S W. AS NEXT WK PROGRESSES THAT HIGH LOOKS TO TRACK FURTHER S...MOST LKLY CAUSING THAT AIR MASS IN THE MID ATLC TO MODIFY AND BECOME MORE "TYPICAL" W/ INCRSG HEAT AND HUMIDITY. PCPN LOOKS TO BE HELD AT BAY THRU MID WK. && .AVIATION /01Z FRIDAY THROUGH TUESDAY/... SHRA/TSRA WL BECOME MORE NMRS OVNGT. VSBY IMPACTS WL BE LCLZD... BUT POTENTIALY AOB IFR. DUE TO DIFFICULTIES PINPOINTING SPECIFICS IN A TAF STYLE FCST...HV KEPT VSBYS IN MVFR. WL ADD DETAILS IF/WHEN THAT BECOMES CLR. CIGS...ON THE OTHER HAND...SHUD BE LWRG...SPCLY IN THE S/W WHERE RESIDUAL MSTR WL BE LEFT BHD BY DAWN. ON TOP OF MVFR CIGS EVERYWHERE...AM TAKING STRONG GDNC SIGNALS OF IFR FOR CHO. FRI WL BE AN UNSETTLED DAY. AN UPR LOW WL ROTATE TWD AREA... SUGGESTING THAT ANY BONOVC WL ONLY QUICKLY FILL BACK IN. FURTHER...NLY SFC FLOW AND ELY FLOW JUST OFF THE SFC WL INHIBIT MUCH DRYING W/IN THE COLUN. DO NOT XPCT CIGS TO RISE MUCH FM LVLS JUST AFTER SUNRISE. FURTHER SHRA WL ONLY REINFORCE POTL RESTRICTIONS. CONDS CUD REALLY DROP FRI NGT AS RAFL EXITS BUT MOIST LLVL CONDS PREVAIL. DIURNAL SHRA/TSRA WL BECOME INCRSGLY SCARCE THRU THE WKND INTO ELY NEXT WK. THAT MEANS THAT VFR WL PREVAIL FOR A MAJORITY OF THE TIME. && .MARINE... LGT SLY FLOW OVER THE WATERS THIS EVNG. STALLED CDFNT WL BE NEARBY...SO WINDS SHUD REMAIN LGT. WATERS WL EXPERIENCE A ROUND OF SHRA/TSRA OVNGT. WINDS MAY GET A LTL GUSTY...BUT SUSPECT THAT HVY RAIN WL BE THE PRIMARY THREAT. MAY BE ABLE TO NUDGE THE FNT EWD FRI. IF SO...THERE CUD BE A SMALL SURGE IN WNDS. DO NOT HV HIGH CONFIDENCE IN THAT SCENARIO ATTM. CONCERNS ARE THAT AN APPROACHING UPR LOW WL SUPPORT MORE SHRA/TSRA INSTEAD. DO NOT BELIEVE THAT ANYTHING WL BE STRONG ENUF FOR SPECIAL MARINE WARNINGS AS THE LLVLS WL BE ON THE STBL SIDE. HIGH PRES IS XPCTD TO BUILD INTO THE WATERS OVR THE WKND/INTO NEXT WK. NO PROBS XPCTD. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && SYNOPSIS...HTS NEAR TERM...HTS SHORT TERM...HAS LONG TERM...WOODY! AVIATION...HTS MARINE...HTS/WOODY!
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 345 PM EDT THU JUL 11 2013 ANZ530>543-DCZ001-MDZ006-007-011-013-014-016>018-VAZ052>057- 121000- 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- 345 PM EDT THU JUL 11 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 THUNDERSTORMS ARE LIKELY THIS AFTERNOON AND EVENING FOR THE I-95 CORRIDOR SOUTH OF WASHINGTON DC...SOUTHERN MARYLAND AND SURROUNDING WATERS. A FEW STORMS MAY PRODUCE LOCALLY DAMAGING WIND GUSTS ALONG WITH HEAVY DOWNPOURS THAT COULD LEAD TO LOCALIZED FLASH FLOODING. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME. MDZ003>005-009-010-501-502-VAZ025>031-036>040-042-050-051-501>504- WVZ050>053-055-501>506-121000- 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- 345 PM EDT THU JUL 11 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 THUNDERSTORMS ARE LIKELY THIS AFTERNOON AND EVENING EAST OF THE BLUE RIDGE AND SOUTH OF I-66. A FEW STORMS MAY PRODUCE LOCALLY DAMAGING WIND GUSTS ALONG WITH HEAVY DOWNPOURS THAT COULD LEAD TO LOCALIZED FLASH FLOODING. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1202 AM EDT FRI JUL 12 2013
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1159 PM FLASH FLOOD 1 SW NEWPORT 38.57N 78.61W
07/11/2013 PAGE VA 911 CALL CENTER
MULTIPLE ROADS CLOSED IN PAGE COUNTY - NEWPORT
RD...GROVE HILL RUN...DAM ACRES LANE... CUB RUN FARM
LANE
&&
EVENT NUMBER LWX1300617
WOODY!PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1248 AM EDT FRI JUL 12 2013
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1157 PM FLASH FLOOD 1 SSW CLOVER HILL 38.43N 79.04W
07/11/2013 ROCKINGHAM VA 911 CALL CENTER
WATER RESCUE NEAR 8700 BLOCK OF WAGGYS CREEK RD
&&
EVENT NUMBER LWX1300618
JRKPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1249 AM EDT FRI JUL 12 2013
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1215 AM FLASH FLOOD 1 W MONTEZUMA 38.41N 79.00W
07/12/2013 ROCKINGHAM VA 911 CALL CENTER
WATER RESCUE NEAR BEAVER CREEK RD AND SILVER CREEK RD
&&
EVENT NUMBER LWX1300619
JRKPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1252 AM EDT FRI JUL 12 2013
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1200 AM FLASH FLOOD HARRISONBURG 38.44N 78.87W
07/12/2013 CITY OF HARRISONBU VA 911 CALL CENTER
15 ROADS CLOSED OR IMPASSABLE IN THE CITY AND IN
ROCKINGHAM COUNTY
&&
EVENT NUMBER LWX1300620
JRKPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
105 AM EDT FRI JUL 12 2013
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1202 AM FLASH FLOOD 2 SSW STERLING 38.98N 77.44W
07/12/2013 LOUDOUN VA FIRE DEPT/RESCUE
WATER RESCUE ON RELOCATION DR BETWEEN UNDERWOOD LN AND
EXECUTIVE DR
&&
EVENT NUMBER LWX1300621
JRKPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
127 AM EDT FRI JUL 12 2013
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1042 PM FLASH FLOOD 2 SSW IVY 38.03N 78.61W
07/11/2013 ALBEMARLE VA 911 CALL CENTER
ROAD CLOSED DUE TO FLASH FLOODING AT 3600 BLOCK OF DICK
WOODS RD
&&
EVENT NUMBER LWX1300622
JRKThe Sterling radar (KLWX), 33 km away, was scanning. The volume nearest the first event began at 05:29 UTC.
5 flash flood. Local standard time, as filed.
There was a water rescue at Little Falls Parkway near Massachusetts Ave.
These roads were closed: River Road, Golfsboro, Macarthur Blvd, Goldleaf and Cabin John Parkway.
There was a water rescue on Livingstone Road and multiple intersections were flooded on Oxon Hill.
Polling House road was closed between Sigma Drive and Bayard Road.
The 400 block of Walnut Drive was closed due to flooding.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Maryland in 2013Every state in 2013This day in weather historyWarnings in Maryland, July 2013
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: 467727, 467726, 467734, 467736, 467738.