Hot and humid conditions persisted across the Mid Atlantic ahead of a advancing cold front. Showers and thunderstorms formed in the vicinity of a surface trough.
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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.
Hot and humid conditions persisted across the Mid Atlantic ahead of a advancing cold front. Showers and thunderstorms formed in the vicinity of a surface trough. Some thunderstorms became severe leading to damaging winds.
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 Sep 2, 2:15 PM EST, 2 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 315 PM EDT TUE SEP 2 2014 .SYNOPSIS... BERMUDA HIGH WILL PERSIST THIS AFTERNOON AHEAD OF A WEAK COLD FRONT THAT WILL CROSS THE AREA TONIGHT. HIGH PRESSURE WILL THEN BUILD FROM THE MIDWEST THROUGH WEDNESDAY THEN PERSIST OFFSHORE THURSDAY INTO THE WEEKEND. A COLD FRONT WILL ENTER THE REGION IN THE SATURDAY NIGHT TIME FRAME. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... VERY WARM AND MOIST AIR MASS PERSISTED OVER THE MID-ATLANTIC THIS AFTERNOON. TEMPERATURES WERE RISING INTO THE LOWER 90S IN MANY AREAS AND THE COMBINATION OF HEAT AND HUMIDITY WAS MAKING IT FEEL MORE LIKE THE MID TO UPPER 90S EAST OF THE BLUE RIDGE. HEAT AND HUMIDITY WILL HELP TO FUEL THUNDERSTORMS THIS AFTERNOON INTO THIS EVENING. WE HAVE SEEN CUMULUS DEVELOPMENT ALREADY...ALTHOUGH CU HAVE HAD LIMITED VERTICAL GROWTH THUS FAR DUE TO SOME CAPPING. THIS IS EXPECTED TO CHANGE LATER THIS AFTERNOON INTO THE EVENING. WE WILL HAVE TO WATCH CONVECTION THAT MAY DEVELOP NEAR A SURFACE TROUGH THIS AFTERNOON. THERE/S ALSO UPSTREAM CONVECTION IN CENTRAL WV /CONVECTION WHICH RE-FIRED/INTENSIFIED FROM EARLY MORNING OHIO VALLEY CONVECTION/ WHICH WILL MOVE EAST WITH TIME...AND THERE COULD ALSO BE ADDITIONAL UPSTREAM CONVECTION LATER ON MORE DIRECTLY ALONG/AHEAD OF THE COLD FRONT. THUS THERE MAY BE SEVERAL CLUSTERS OF CONVECTION TO KEEP AN EYE ON THROUGH THIS EVENING. HOWEVER...DETAILS REGARDING THE EXACT EVOLUTION AND COVERAGE OF ANY ONE REMAIN SOMEWHAT UNCERTAIN. BASED ON RADAR TRENDS...WILL HAVE LIKELY POPS ACROSS THE NORTHWEST PORTION OF THE CWA. FURTHER DOWNSTREAM...WILL KEEP POPS IN THE CHANCE/SCATTERED CATEGORY BUT THESE MAY NEED TO BE BUMPED UP IF ANY ONE CLUSTER CONGEALS AS IT MOVES EAST EITHER LATER THIS AFTERNOON OR THIS EVENING. MODIFIED 12Z KIAD RAOB INDICATED AROUND 3000 J/KG OF CAPE. PRECIPITABLE WATER VALUE WAS AROUND 1.8 INCHES...THIS MAY BE CLOSER TO 2 INCHES BY 00Z. INSTABILITY AND MOISTURE WILL BE DECENT...HOWEVER BETTER SHEAR LIKELY RESIDES JUST NORTHWEST OF THE CWA. THIS MAY LIMIT A WIDESPREAD SEVERE RISK...HOWEVER BUOYANCY ALONE COULD FOSTER A FEW THUNDERSTORMS PRODUCING DAMAGING WIND GUSTS THROUGH THIS EVENING. GIVEN HIGH MOISTURE CONTENT...HEAVY RAINFALL WILL ALSO OCCUR IN THE STRONGEST STORMS. BUT GIVEN FORECAST STORM MOTION...STORMS SHOULD MOVE ENOUGH TO PRECLUDE A FLASH FLOODING RISK UNLESS TRAINING WERE TO OCCUR. COLD FRONT EVENTUALLY CATCHES UP TO THE TROUGH LATER THIS EVENING...MOVING OFFSHORE TONIGHT. CHANCE OF THUNDERSTORMS WILL END BEHIND THE COLD FRONT. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... CWA WILL BE POST-FRONTAL ON WEDNESDAY. NORTHWEST WINDS WILL BRING SOME DRYING THROUGH THE CWA...LEADING TO PLENTY OF SUNSHINE AND LOWER HUMIDITY. FRONT LOOKS LIKE IT GETS HUNG UP IN SOUTHERN VIRGINIA AS WEAK HIGH PRESSURE BUILDS IN FROM THE NORTH. HIGH MOVES OFFSHORE ON THURSDAY. MAY SEE ISOLATED SHOWERS AND THUNDERSTORMS DEVELOP UP/NEAR THE BLUE RIDGE BY AFTERNOON. ACTIVITY WOULD LIKELY BE DIURNAL IN NATURE. TROUGH DEVELOPS ON FRIDAY...WITH THE POTENTIAL FOR MORE DIURNAL CONVECTION. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... ANOTHER COLD FRONT APPROACHES FRIDAY NIGHT. QUESTION IS HOW QUICKLY THE FRONT PUSHES THROUGH THE AREA. IT MAY MOVE THROUGH BY SATURDAY NIGHT...BUT ITS POSSIBLE IT DOESN/T CLEAR THE SOUTHEAST PART OF THE CWA UNTIL SUNDAY. HIGH PRESSURE AND DRY AIRMASS WILL BUILD INTO THE AREA MONDAY. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... MAIN ISSUE REVOLVES AROUND AFTERNOON AND EVENING CONVECTION. FOCUSED ON LATE AFTERNOON INTO THE EVENING FOR THE HUBS MAINLY BASED ON UPSTREAM CONVECTION OVER WV AND AHEAD OF THE COLD FRONT...ALTHOUGH ISOLATED TSRA AHEAD OF THESE CAN NOT BE RULED OUT EARLIER. COLD FRONT MOVES THROUGH LATE IN THE EVENING WITH A WIND SHIFT TO THE NORTHWEST. LOW LEVEL MOISTURE LINGERS TONIGHT. IF WINDS BECOME CALM...FOG MAY FORM. THIS APPEARS MOST LIKELY AT CHO. EXPECTATION IS FOR ENOUGH WIND TO OCCUR AT OTHER SITES TO INHIBIT FOG FORMATION. VFR EXPECTED WEDNESDAY POST-FRONTAL AND WITH HIGH PRESSURE IN CONTROL. HIGH MOVES OFFSHORE TO END THE WEEK. NEXT COLD FRONT WILL AFFECT THE AREA OVER THE WEEKEND. && .MARINE... PRIMARY CONCERN LATE THIS AFTERNOON AND EVENING WILL BE STRONG GUSTY WINDS AND LIGHTNING IN SCATTERED SHOWERS AND THUNDERSTORMS. SMW/S MAY BECOME NECESSARY. CHANCE OF THUNDERSTORMS WILL CONTINUE UNTIL A COLD FRONT PASSES TONIGHT. HIGH PRESSURE BUILDS IN FOR WEDNESDAY THEN MOVES OFFSHORE TO END THE WEEK. COLD FRONT MOVES THROUGH OVER THE WEEKEND. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && SYNOPSIS...BPP NEAR TERM...BPP SHORT TERM...BPP LONG TERM...CEM AVIATION...BPP/CEM MARINE...BPP/CEM
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 854 AM EDT TUE SEP 2 2014 ANZ530>543-DCZ001-MDZ006-007-011-013-014-016>018-VAZ052>057- 031000- 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- 854 AM EDT TUE SEP 2 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...TODAY AND TONIGHT A FEW THUNDERSTORMS MAY BE CAPABLE OF PRODUCING DAMAGING WIND GUSTS DURING THE LATE AFTERNOON AND EVENING. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY 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>506-031000- 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- 854 AM EDT TUE SEP 2 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...TODAY AND TONIGHT A FEW THUNDERSTORMS MAY BE CAPABLE OF PRODUCING DAMAGING WIND GUSTS THIS AFTERNOON AND EVENING. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NECESSARY THIS AFTERNOON AND EVENING.
The Sterling radar (KLWX), 146 km away, was scanning. The volume nearest the first event began at 19:15 UTC.
17 thunderstorm wind. Local standard time, as filed.
There were trees and power lines down.
There were two large tree branches down. The tree branches were 5-6 inches wide.
There was a large tree down at the intersection of Routes 109 and 107.
There were numerous trees down off Norbeck Road between MD 200 and Georgia Avenue.
There was a tree and power lines down at Church St. and West Side Ave.
There was a large tree down blocking road.
There were at least 25 1.5-2 feet in diameter trees down on a Golf Course.
There was a tree down on the road in the 4500 Block of Elmer Derr Road.
There was a tree down near the intersection of Bullfrog Road and Mcmullen Road.
There was a tree down across Mayberry Road.
There were trees and power lines down near the intersection of Bradford and Norbeck Road.
There were two trees down on houses causing significant damage near each other, one on the 1000 Block of Evergreen Ave and one on the 6400 Block of Bellview Ave.
There was a tree down at the intersection of Brokenland Parkway and Cradlerock Way.
There was a tree down at the intersection of Quiet Hours and Cradlerock Way.
There were large tree limbs down at the intersection of Seneca and Groveleigh.
There was a tree down at the intersection of Mayfield Avenue and Meadowridge Road.
There was a tree down across the road near the intersection of Abingdon Road and Route 40.
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, September 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: 542577, 542578, 542579, 542580, 542581, 542582, 542584, 542583, 542585, 542586, 542587, 542593, 542588, 542589, 542590, 542591, 542592.