Moisture moved into the the region as a upper level trough moved across the Great Lakes. Destabilization occurred as cloud cover led to many breaks of sunshine across the Mid Atlantic.
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.
Moisture moved into the the region as a upper level trough moved across the Great Lakes. Destabilization occurred as cloud cover led to many breaks of sunshine across the Mid Atlantic. Showers and thunderstorms formed near and west of the Blue Ridge Mountains.
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 May 10, 9:30 AM EST, 3 hours 6 minutes earlier.
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1030 AM EDT SAT MAY 10 2014
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL LEAD TO WARM AND HUMID
CONDITIONS THIS WEEKEND THROUGH THE FIRST PART OF THE NEW WEEK. A
COLD FRONT WILL ENTER THE REGION DURING MIDWEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE MIDDLE ATLANTIC REGION WILL REMAIN SANDWICHED IN BETWEEN A
RIDGE TO THE SOUTH AND AN UPPER TROUGH OVER THE GREAT LAKES
STATES. THE FLOW AROUND THESE SYSTEMS IS HELPING TO PULL ABUNDANT
MID AND HIGH LEVEL MOISTURE ACROSS THE MIDDLE ATLANTIC. WE EXPECT
CLOUD COVER TO CONTINUE TO STREAM IN FROM THE SOUTHWEST TODAY. AT
THE LOWER LEVELS...SOUTHERLY FLOW IS AIDING IN MOIST CONDITIONS
WITH DEWPOINTS IN THE 60S COMMON JUST ABOUT EVERYWHERE THIS
MORNING. BREAKS IN THE CLOUD DECK HAVE OCCURRED EAST OF THE BLUE
RIDGE WHICH HAS AIDED IN DESTABILIZING THE BOUNDARY LAYER A BIT
MORE THAN EXPECTED. THIS SHOULD LEAD TO BETTER MIXING AT LEAST
EARLY ON WITH TEMPERATURES APPROACHING THE LOWER 80S EAST OF THE
MOUNTAINS. SOUNDING PROFILE THIS AM AT KIAD INDICATED STEEPENING
LAPSE RATES WITH POTENTIAL FOR GUSTY WINDS WITH ANY
SHOWERS/THUNDERSTORMS THAT DEVELOP A BIT LATER TODAY. CAP WILL
HOLD OVER THE NEXT FEW HOURS OVER THE METRO AREAS BEFORE HEATING
CAUSES EROSION OF THE CIN. CAPE MAY BE AMPLE ENOUGH AND WITH
ENERGY APPROACHING FROM THE WEST...WILL SEE SHOWERS AND ISOLATED
THUNDERSTORMS DEVELOPING...SOME OF WHICH MAY PRODUCE DAMAGING
WINDS.
THREAT FOR SHOWERS AND THUNDERSTORMS WILL LIKELY DIMINISH LATER
THIS EVENING BUT CLOUDS WILL REMAIN IN PLACE OVERNIGHT. LOW TEMPS
WILL FALL BACK TO THE 60S IN THE METRO AREAS AND 50S ELSEWHERE.
&&
.SHORT TERM /SUNDAY/...
SUNDAY...RIDGING MAKES FOR A NICE MOTHERS DAY. LIGHT NWLY FLOW
BECOMES WLY. THE DOWNSLOPING FLOW AND SUNNY SKIES...AND 10 TO 12C
850MB TEMPS MAKE FOR MAX TEMPS IN THE LOW 80S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
THE LONG TERM CAN SORT OF BE DIVIDED INTO 2 PARTS - THE SUMMERY
PART F0LLOWED BY THE WETTER PART W/ TEMPS MORE TYPICAL OF ERLY
MAY.
A SUBTROPICAL RDG REMINISCENT OF WHAT THIS AREA OFTEN SEES IN JUL
WL BE THE DOMINANT WX FACTOR FM SUN NGT INTO SOME POINT IN MIDWK.
THIS WL CAUSE LOW TEMPS TO RISE FM THE U50S SUN NGT TO THE LM60S
MON AND TUE NGT. HIGHS MON AND TUE WL LKLY REACH THE U80S...PSBLY
EVEN 90 IN SPOTS. CNVCTN WL LKLY BE RESTRICTED TO MTNS ON MON.
TSTMS AGN PSBL TUE AFTN/EVE.
INCRSD CLD CVRG ON WED AHD OF SFC FNT/UPR LVL TROF ENTERING THE MS
VLLY. THIS SHOULD HINDER INSOLATION AND ALLOW TEMPS TO BE HELD TO
THE L80S. CHCS OF PCPN SHOULD EXIST DURG THE DAY..BUT THE BEST
CHCS SHOULD BE WED AFTN/EVE AS THE FNT DRAWS CLOSER.
CLRG MAY BE SLOW TO COME...AS THE FNT APPEARS TO BE CAUGHT IN SSW-
NNE UPR LVL FLOW. THIS IN TURN WL KEEP PCPN CHCS OVR THE AREA FOR
MUCH OF THE 2ND HALF OF THE WK. XTNSV CLD CVR WL ACT TO HOLD
TEMPS DOWN - HIGHS IN THE 70S/LOWS FALLING BACK INTO THE 50S THU
NGT. THIS WL ALSO WORK TO TEMPER SVR THREAT.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP THIS AFTERNOON AND
CONTINUE INTO THIS EVENING. SOME OF THE STORMS COULD PRODUCE GUSTY
WINDS AND HEAVY DOWNPOURS. WILL CONTINUE MENTION WITHIN THE
TERMINAL FORECASTS. THREAT WILL DIMINISH BY LATE EVENING. VFR
CONDITIONS EXPECTED SUNDAY INTO MONDAY.
CNVCTV CHCS WL EXIST FM TUE AFTN THRU MUCH OF THE REST OF THE
WK...ALTHO SVR CONDS NOT XPCTD. THE 2ND HALF OF THE WK IS ALSO
XPCTD TO BE QUITE CLDY.
&&
.MARINE...
SWLY FLOW INCREASES THROUGH THE DAY WITH SCA FOR ALL WATERS BY NOON.
20 TO 25 KT GUSTS. GUSTY SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE LATER THIS AFTERNOON INTO THIS EVENING WHICH MAY WARRANT
SPECIAL MARINE WARNINGS.
WINDS MAY PICK UP ON THU AS A CD FNT MOVES THRU THE WATERS. AN SCA
MAY BE NEEDED. AFTR A VERY WARM 1ST HALF OF THE WK...W/ PSBL TSTM
CHCS TUE...CLDS WL INCRS W/ COOLER TEMPS AND CHCS OF RA/ISOLD
TSTMS FOR THE 2ND HALF OF THE WK.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SUNDAY FOR ANZ530>533-535-
536-538>542.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT SUNDAY FOR ANZ534-537-543.
&&
SYNOPSIS...KRW
NEAR TERM...KRW
SHORT TERM...KS
LONG TERM...ABW
AVIATION...KRW
MARINE...KRWHAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1039 AM EDT SAT MAY 10 2014 ANZ530>543-DCZ001-MDZ006-007-011-013-014-016>018-VAZ052>057- 111245- 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- 1039 AM EDT SAT MAY 10 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 SMALL CRAFT ADVISORY IS IN EFFECT FOR LOWER SOUTHERN MARYLAND WATERS THIS MORNING...THEN EXPANDS TO ALL WATERS FOR THIS AFTERNOON INTO TONIGHT. GUSTY SHOWERS AND THUNDERSTORMS ARE LIKELY ACROSS THE WATERS THIS EVENING. SPECIAL MARINE WARNINGS MAY BE NECESSARY. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY A SMALL CRAFT ADVISORY MAY BE REQUIRED THURSDAY. .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>506-111245- 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- 1039 AM EDT SAT MAY 10 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 SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP ACROSS THE REGION THIS AFTERNOON INTO THIS EVENING. SOME OF THE STORMS COULD PRODUCE DAMAGING WINDS. THE THREAT WILL DIMINISH BY LATE EVENING. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.
The Sterling radar (KLWX), 42 km away, was scanning. The volume nearest the first event began at 17:35 UTC.
3 thunderstorm wind. Local standard time, as filed.
There was a tree down near the intersection of Tabler Road and Urbana Pike.
There was a tree down near the intersection of Baker Valley Road and Araby Church Road.
There were trees down onto wires at the 5900 Block of Boyers Mill 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, May 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: 520189, 520190, 520191.