A surface trough was across the Mid-Atlantic and warm and humid conditions led to a unstable environment. Showers and thunderstorms formed near the surface trough.
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 surface trough was across the Mid-Atlantic and warm and humid conditions led to a unstable environment. Showers and thunderstorms formed near the surface trough. Damaging winds and large hail were reported in some thunderstorms.
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 3, 1:30 PM EST, 4 hours 45 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 230 PM EDT SUN AUG 3 2014 .SYNOPSIS... A SURFACE TROUGH WILL REMAIN OVER THE REGION THROUGH TUESDAY. A WEAK COLD FRONT WILL PASS THROUGH THE REGION WEDNESDAY AND HIGH PRESSURE WILL BUILD IN FOR LATE IN THE WEEK. && .NEAR TERM /THROUGH MONDAY/... CURRENT ANALYSIS SHOWS AN UPPER-LEVEL LOW TRACKING THROUGH PENNSYLVANIA WHILE A SURFACE TROUGH REMAINS EAST OF THE ALLEGHENY HIGHLANDS. HIGH PRESSURE REMAINS OFF THE MID-ATLANTIC COAST. A BKN CU DECK HAS DEVELOPED THIS AFTERNOON FROM AN ONSHORE FLOW...BUT THERE HAVE BEEN ENOUGH BREAKS OF SUN FOR MAX TEMPS TO REACH THE LOWER AND MIDDLE 80S ACROSS MOST LOCATIONS. THE CLOUD DECK HAS BEEN A BIT THICKER ACROSS NORTHEASTERN MARYLAND...SO MAX TEMPS WILL BE A FEW DEGREES COOLER ACROSS THESE LOCATIONS. THE WARM AND HUMID AIR HAS LED TO SOME INSTABILITY...BUT INSTABILITY IS LIMITED FROM A DRY SLOT OVERHEAD AND A WEAK INVERSION IN THE MID-LEVELS OF THE ATMOSPHERE. NAM/GFS BUFKIT ARE INDICATING AROUND 500-1000J/KG OF MLCAPE THIS AFTERNOON. THE FORCING FROM THE SURFACE TROUGH...TERRAIN CIRCULATION AND SHORTWAVE ENERGY ASSOCIATED WITH THE 500MB LOW OVER PA WILL BE ENOUGH TO TRIGGER A FEW SHOWERS AND THUNDERSTORMS. THE BEST CHANCE FOR PRECIPITATION WILL BE LATE THIS AFTERNOON AND EVENING ACROSS NORTHERN MARYLAND...CLOSER TO THE 500MB LOW. THE 500MB LOW WILL MOVE AWAY FROM THE AREA LATER TONIGHT AND DRY CONDITIONS ARE EXPECTED BEHIND IT. LOW-LEVEL MOISTURE TRAPPED UNDERNEATH THE NOCTURNAL INVERSION WILL CAUSE SOME FOG...ESPECIALLY IN THE SHELTERED VALLEYS AND RURAL AREAS. HEIGHTS WILL RISE MONDAY BEHIND THE DEPARTING DISTURBANCE...BUT THE SURFACE TROUGH WILL REMAIN OVERHEAD. MORE SUNSHINE AND HIGHER HEIGHTS WILL ALLOW FOR SEASONABLY HOTTER CONDITIONS. MAX TEMPS WILL RANGE FROM THE 70S IN THE MOUNTAINS TO THE MID AND UPPER 80S ACROSS MOST OTHER LOCATIONS. A SHOWER OR THUNDERSTORM CANNOT BE RULED OUT...MAINLY EAST OF THE SURFACE TROUGH OVER SOUTHERN MARYLAND. HOWEVER...MUCH OF THE TIME WILL BE DRY AND MOST AREAS WILL ALSO TURN OUT DRY FOR THE ENTIRE DAY. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/... AN UPPER-LEVEL TROUGH WILL BUILD OVERHEAD MONDAY NIGHT THROUGH WEDNESDAY WHILE BERTH PASSES BY TO OUR EAST. A SURFACE TROUGH WILL ALSO REMAIN OVER THE REGION DURING THIS TIME. SEASONABLY WARM AND HUMID CONDITIONS ARE EXPECTED DURING THIS TIME ALONG WITH THE CHANCE FOR SHOWERS AND THUNDERSTORMS. THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS WILL BE DURING THE AFTERNOON AND EVENING HOURS TUESDAY AND WEDNESDAY. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... HIGH PRESSURE CENTERED OVER QUEBEC WILL NOSE ITS WAY IN ON WED NIGHT AND SETTLE ACROSS THE REGION THROUGH SUN. POTL FOR TERRAIN BASED SHRA/TSTMS WILL BEGIN ON THU AFT WITH WEAK WIND PROFILE. GULF MOISTURE WILL RIDE UP INTO SE U.S. DURING THIS TIME...AND EXPECT THE BOUNDARY BETWEEN THIS WARM MOIST AIR AND THE QUEBEC HIGH WILL BE SOUTH OF CWA PER THE 00Z ECMWF. 12Z MEX FOR DCA HAS TEMPS IN THIS PERIOD SLIGHTLY BELOW NORMAL FOR DAYTIME HIGHS AND SLIGHTLY ABOVE NORMAL FOR NIGHT TIME LOWS. SEVERE WX CHANCES APPEAR BELOW NORMAL AS WELL. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... A FEW SHOWERS AND THUNDERSTORMS ARE POSSIBLE THIS EVENING...BUT MUCH OF THE TIME WILL BE DRY. AREAS OF FOG ARE EXPECTED OVERNIGHT WITH MVFR/IFR VSBYS. ANY FOG WILL BURN OFF BY MID-MORNING MONDAY AND VFR CONDITIONS ARE EXPECTED THE REST OF MONDAY ALONG WITH LIGHT WINDS. AN UPPER-LEVEL TROUGH WILL BUILD OVERHEAD TUESDAY AND WEDNESDAY. A COUPLE AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS ARE POSSIBLE. OTHERWISE...MOST OF THE TIME WILL BE WITH VFR CONDITIONS. VFR CONDITIONS EXPECTED DAYS 4-7. && .MARINE... A SURFACE TROUGH WILL REMAIN OVER THE WATERS THROUGH TUESDAY...BUT THE PRESSURE GRADIENT WILL BE WEAK. WINDS WILL BE LIGHT DURING THIS TIME. A WEAK COLD FRONT WILL MOVE INTO THE AREA WEDNESDAY...BUT WIND SPEEDS SHOULD STILL REMAIN BELOW SCA CRITERIA. BEST CHANCE FOR SCA WINDS OVER THE NEXT WEEK WILL BE POST FRONTAL ON THURSDAY. OTHERWISE...VERY WEAK WIND FIELD AOB H85 THROUGH DAY 7. && .TIDES/COASTAL FLOODING... AN ONSHORE FLOW HAS CAUSED TIDAL ANOMALIES TO RISE TO BETWEEN 0.75 AND 1 FOOT ABOVE NORMAL. THE POSITIVE TIDAL ANOMALIES SHOULD CONTINUE THROUGH THE HIGH TIDE CYCLE TONIGHT. DUE FEEL THAT THE ONSHORE FLOW WILL BE LIGHT ENOUGH TO PREVENT MINOR COASTAL FLOODING...BUT IT WILL BE CLOSE FOR ANNAPOLIS IN ANNE ARUNDEL COUNTY. HIGH TIDE IS AT 11:58 PM THIS EVENING. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && SYNOPSIS...BJL NEAR TERM...BJL SHORT TERM...BJL LONG TERM...LEE AVIATION...BJL/LEE MARINE...BJL/LEE TIDES/COASTAL FLOODING...BJL
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 624 PM EDT SUN AUG 3 2014 ANZ530>543-DCZ001-MDZ006-007-011-013-014-016>018-VAZ052>057- 041000- 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- 624 PM EDT SUN AUG 3 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...TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. MDZ003>005-009-010-501-502-VAZ025>031-036>040-042-050-051-501>504- WVZ050>053-055-501>506-041000- 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- 624 PM EDT SUN AUG 3 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...TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.
The Sterling radar (KLWX), 79 km away, was scanning. The volume nearest the first event began at 23:15 UTC.
1 thunderstorm wind, 1 hail. Local standard time, as filed.
There was a tree down on Buck Lantz Road.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Maryland in 2014Every state in 2014This day in weather historyWarnings in Maryland, 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: 540079, 540080.