A surface trough triggered some showers and thunderstorms over Maryland. An isolated thunderstorm did produce damaging winds due to moderate amounts of instability ahead of the 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 triggered some showers and thunderstorms over Maryland. An isolated thunderstorm did produce damaging winds due to moderate amounts of instability ahead of the trough.
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 16, 3:04 PM EST, 26 minutes earlier.
AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 404 PM EDT MON AUG 16 2010 .SYNOPSIS... A COLD FRONT WILL STALL ACROSS CENTRAL MARYLAND AND EASTERN VIRGINIA THIS EVENING...THEN PERSIST ACROSS THE SOUTHERN MID ATLANTIC THROUGH THE MIDDLE PART OF THE WEEK. AN AREA OF LOW PRESSURE WILL MOVE NORTHEAST ALONG THE FRONTAL BOUNDARY AND ACROSS THE MID ATLANTIC WEDNESDAY AND INTO THURSDAY. HIGH PRESSURE WILL BUILD IN BEHIND THE LOW WITH THE NEXT DISTURBANCE CROSSING THE AREA OVER THE WEEKEND. && .NEAR TERM /THROUGH TUESDAY/... CDFNT STTLG INTO SHEN VLY ATTM. AMS AHD OF FNT VERY WARM...HUMID /DEWPTS MID 70S/ AND UNSTBL. A SPL 17Z RAOB INDICATED 3500 J/KG CAPE UNMODIFIED. SHEAR VALUES HV INCRSD IN RESPONSE TO S/WV WELL N OF AREA. HGTS ALSO DROPPING AND LAPSE RATES INCR IN RESPONSE TO THAT FEATURE. RRQ OF UPR JET ALSO ASSISTS. COMBINE THESE CONSIDERATIONS...AND A SVR TSTM WATCH HAS BEEN ISSUED TIL 10 PM. LTST NAM/GFS/WRF/HRRR ALL DEPICT A SIMLR SCENARIO...SUGGESTING THAT THE SCT TSTM CELLS WL BECOME MORE NMRS SHORTLY...AND DVLP INTO MULTICELL CLUSTERS SWEEPING ACRS CWFA FM BLURDG TO THE BAY. THAT FCST HASNT CHGD MUCH IN PAST 24 HRS...ADDED CONFIDENCE IN ITS SOLN. TIMING PLACES ACTVTY IN METRO CRRDR FOR AFTN RUSH HR...AND THEN STORMS WL LINGER IN SRN MD AS SFC FNT BECOMES PARALLEL TO UPR FLOW. AM CONCERNED THAT TSRA MAY LINGER ACRS SRN MD...PERHAPS PAST MIDNGT. WL KEEP CHC TSRA FOR THEN AS OPPOSED TO NMRS. THE DRIER AIR WL BE SITTING NW OF CWFA...BUT AM HAVING DOUBTS AS TO WHETHER IT WL MAKE IN IN. HV GONE A CLICK OR TWO ABV THE WARMEST GDNC FOR MIN-T TNGT. BNDRY WL STILL BE NEARBY TMRW. THE KEY FOR TMRWS FCST REMAINS HOW FAR S THE CDFNT MAKES IT...AND HOW MUCH COOL/DRY AIR ADVTCN CAN BE REALIZED. WHILE WE/LL LKLY SEE A LGT NLY FLOW...DONT THINK THE THERMAL GRADIENT WL MAKE IT. 12Z RUNS SUGGEST ITLL BE HUNG UP ACRS APPLCHNS. HWVR...LWR DEWPTS SHUD. HV KEPT CHC TSRA ACRS SRN CNTYS...AND PT-MOSUN TO THE N...WHERE THE MID 50S-LWR 60S DEWPTS WL BE. MAXT CLOSE TO MOS. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/... MODEL CONSENSUS FOR THE STATIONARY FRONT TO BE STILL ACROSS DELMARVA SW TO WRN VA TUE NIGHT. A SHORTWAVE TROUGH MOVING EAST FROM THE CENTRAL CONUS ON TUE TO CROSS THE MID ATLANTIC AND DRAW THE BOUNDARY NORTH AS A WARM FRONT WITH WEAK EMBEDDED LOW PRESSURE ON WED. WITH SUBTROPICAL MOISTURE CONTINUING TO PUMP NORTH FROM THE GULF VIA THE BERMUDA HIGH...HEAVY THUNDERSTORM/FLASH FLOOD POTENTIAL IS EXPECTED TO BUILD NORTH ACROSS THE CWA THROUGH THE DAY WED. BUMPED UP POPS TO CATEGORICAL BY WED AFTERNOON WITH HEAVY PRECIP WORDING IN THE WX GRIDS. MAIN SHORTWAVE TROUGH/LOW TO PUSH NORTHEAST OFF THE COAST WED NIGHT...THOUGH A SECONDARY LOW TO PROVIDE ANOTHER ROUND OF ACTIVE WX THROUGH THURSDAY. MAX TEMPS SUPPRESSED BOTH DAYS DUE TO LOW COVER AND PRECIP...LOW TO MID 80S ON WED...MID TO UPPER 80S THUR. && .LONG TERM /FRIDAY THROUGH MONDAY/... RIDGING AHEAD OF THE NEXT DISTURBANCE PUSHES BOUNDARY SOUTH OF THE CWA THURSDAY NIGHT AND FRIDAY...ALLOWING GREATER SUNSHINE AND A RETURN TO ABOVE NORMAL TEMPERATURES INTO THE WEEKEND. THERE IS DISAGREEMENT OVER TIMING OF THE NEXT SYSTEM BETWEEN THE GFS AND EURO... WENT WITH SLIGHT CHANCE POPS FOR MAJORITY OF THE AREA ON SATURDAY AS A HEDGE AGAINST THE SLOWER EURO BEING TOO SLOW WITH PRECIP. WITH LOW PRESSURE JUST NORTH OF THE GREAT LAKES...ANY BOUNDARY DRAGGING ACROSS THE MID ATLANTIC MAY BE WEAKENING AS IT PASSES /AS DEPICTED BY THE EURO FOR SUNDAY NIGHT/. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... CDFNT INVOF SHEN VLY ATTM. FROPA WL PROGRESS ACRS AREA TAFTN...AND SHUD BE COINCIDENT W/ THE AFTN PUSH FOR THE METROS. LOOK FOR NMRS TSRA ALONG/AHEAD OF THE FRONT...SOME WL CONTAIN STRONG/GUSTY WNDS. PLACED TEMPO G30-35 KT IN TAFS...BUT IF AN AIRFIELD GETS A DIRECT STRIKE...IT CUD BE HIER. VFR AFTR TSRA...BUT IT/LL TAKE A WHILE FOR THE DRIER AIR TO WORK IN. AM CONCERNED ABT ELY MRNG FOG. HV LIMITED IT TO MVFR ATTM...XCPT FOR CHO. ENUF DRY AIR WL WORK IN TMRW FOR VFR CONDS. MAY BE A SCT TSRA OR TWO INVOF CHO...BUT AFTR 18Z VALID PD. SOME FOG POSSIBLE TUE NIGHT WITH MOIST AIRMASS AND A FRONTAL BOUNDARY LINGERS ACROSS SOUTHERN VIRGINIA. BOUNDARY LIFTS AS A WARM FRONT WITH EMBEDDED LOW PRESSURE ACROSS THE TERMINALS THROUGH WED. VERY MOIST WITH POTENTIAL FOR VERY HEAVY RAIN/LIFR CONDITIONS DURING PRECIP WED/WED NIGHT. ANOTHER WEAK DISTURBANCE BRINGS MORE PRECIP FOR THURSDAY...THEN VFR RETURNS FOR FRIDAY. THE NEXT FRONT APPROACHES THE MID ATLANTIC OVER THE WEEKEND. && .MARINE... SLY WNDS TAFTN-EVE...10-15 KT. HWVR...CDFNT APPCHG...CONTAINING NMRS TSRA. THESE STORMS HV GUSTY WIND POTENTIAL. SMW/S MAY BE REQD INVOF TSRA LT TAFTN- TNGT. THINKING ANY HIER WND WL BE COINCIDENT W/ CNVCTN...SO HV CAPPED GRADIENT WNDS AT 15 KT. CDFNT WL STALL OUT JUST S OF THE WATERS LT TNGT THRU TMRW. THE WNDS SHUD BE LGT...AOB 10 KT FM THE N. HWVR...THE MID BAY AND A LARGE PORTION OF THE TIDAL PTMC MAY SEE SCT AFTN TSRA. A FRONTAL BOUNDARY LINGERS ACROSS THE VIRGINIA PORTION OF THE BAY TUE NIGHT. BOUNDARY LIFTS AS A WARM FRONT WITH EMBEDDED LOW PRESSURE ACROSS MARYLAND PORTION OF THE BAY THROUGH WED. VERY MOIST WITH POTENTIAL FOR VERY HEAVY RAIN WED/WED NIGHT. ANOTHER WEAK DISTURBANCE BRINGS MORE PRECIP FOR THURSDAY...THEN MORE TRANQUIL FRIDAY. THE NEXT FRONT APPROACHES THE MID ATLANTIC OVER THE WEEKEND. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && SYNOPSIS...BAJ NEAR TERM...HTS SHORT TERM...BAJ LONG TERM...BAJ AVIATION...BAJ/HTS MARINE...BAJ/HTS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 221 PM EDT MON AUG 16 2010 ANZ530>543-DCZ001-MDZ006-007-011-013-014-016>018-VAZ052>057- 171000- 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- 221 PM EDT MON AUG 16 2010 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 SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL NOON FOR THE MAIN CHANNEL OF THE CHESAPEAKE BAY FROM SANDY POINT TO SMITH POINT...AS WELL AS TANGIER SOUND AND THE INLAND WATERS SURROUNDING BLOODSWORTH ISLAND. A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 10 PM. A COLD FRONT WILL CROSS THE AREA...PRODUCING NUMEROUS THUNDERSTORMS. DAMAGING WIND GUSTS WILL BE THE PRIMARY THREAT. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY A WAVE OF LOW PRESSURE WILL MOVE EAST ALONG A STALLED FRONTAL BOUNDARY WEDNESDAY AND WEDNESDAY NIGHT...BRINGING WIDESPREAD RAINS TO THE MID ATLANTIC. THIS SYSTEM HAS THE POTENTIAL TO PRODUCE HEAVY RAINFALL ACROSS REGION. .SPOTTER INFORMATION STATEMENT... THE SKYWARN SPOTTER NETWORK HAS BEEN ACTIVATED. PLEASE FORWARD ANY REPORTS OF SEVERE WEATHER TO THE NATIONAL WEATHER SERVICE. MDZ003>005-009-010-501-502-VAZ021-025>031-036>040-042-050-051-501- 502-WVZ050>055-501>504-171000- WASHINGTON-FREDERICK MD-CARROLL-MONTGOMERY-HOWARD- EXTREME WESTERN ALLEGANY-CENTRAL AND EASTERN ALLEGANY-HIGHLAND- AUGUSTA-ROCKINGHAM-SHENANDOAH-FREDERICK VA-PAGE-WARREN-CLARKE- NELSON-ALBEMARLE-GREENE-MADISON-RAPPAHANNOCK-LOUDOUN-ORANGE- CULPEPER-NORTHERN FAUQUIER-SOUTHERN FAUQUIER-HAMPSHIRE-MORGAN- BERKELEY-JEFFERSON-PENDLETON-HARDY-WESTERN GRANT-EASTERN GRANT- WESTERN MINERAL-EASTERN MINERAL- 221 PM EDT MON AUG 16 2010 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 SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 10 PM FOR THE SHENANDOAH VALLEY EAST. A COLD FRONT WILL CROSS THE AREA...PRODUCING NUMEROUS THUNDERSTORMS. DAMAGING WIND GUSTS WILL BE THE PRIMARY THREAT. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY A WAVE OF LOW PRESSURE WILL MOVE EAST ALONG A STALLED FRONTAL BOUNDARY WEDNESDAY AND WEDNESDAY NIGHT...BRINGING WIDESPREAD RAINS TO THE MID ATLANTIC. THIS SYSTEM HAS THE POTENTIAL TO PRODUCE HEAVY RAINFALL ACROSS REGION. .SPOTTER INFORMATION STATEMENT... THE SKYWARN SPOTTER NETWORK HAS BEEN ACTIVATED. PLEASE FORWARD ANY REPORTS OF SEVERE WEATHER TO THE NATIONAL WEATHER SERVICE. HTS
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 334 PM EDT MON AUG 16 2010 MDZ003-004-162000- WASHINGTON MD-FREDERICK MD- 334 PM EDT MON AUG 16 2010 ...STRONG THUNDERSTORMS TO AFFECT WASHINGTON AND FREDERICK COUNTIES... AT 334 PM EDT...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM OVER LEITERSBURG...MOVING EAST AT 25 MPH. HEAVY RAIN WITH THIS STORM MAY REDUCE VISIBILITIES TO BELOW ONE MILE AND MAY CAUSE PONDING OF WATER ON ROADWAYS. WIND GUSTS OF 40 MPH CAN BE EXPECTED WITH THIS STORM. && LAT...LON 3963 7733 3963 7769 3973 7769 3972 7730 TIME...MOT...LOC 1934Z 264DEG 20KT 3969 7761 PELOQUIN
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
340 PM EDT MON AUG 16 2010
VAZ025-036-162015-
NELSON VA-AUGUSTA VA-
340 PM EDT MON AUG 16 2010
...STRONG THUNDERSTORMS TO AFFECT NELSON AND AUGUSTA COUNTIES...
AT 341 PM EDT...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 2 MILES
SOUTHEAST OF MONTEBELLO...MOVING EAST AT 10 MPH.
HEAVY RAIN WITH THIS STORM MAY REDUCE VISIBILITIES TO BELOW ONE MILE
AND MAY CAUSE PONDING OF WATER ON ROADWAYS.
WIND GUSTS OF 40 TO 50 MPH CAN BE EXPECTED WITH THIS STORM.
&&
LAT...LON 3782 7916 3784 7916 3786 7915 3789 7916
3791 7915 3796 7896 3778 7896
TIME...MOT...LOC 1941Z 265DEG 9KT 3785 7909
KRAMARSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 351 PM EDT MON AUG 16 2010 MDZ003>005-162015- WASHINGTON MD-CARROLL MD-FREDERICK MD- 351 PM EDT MON AUG 16 2010 ...STRONG THUNDERSTORMS TO AFFECT WASHINGTON...CARROLL AND FREDERICK COUNTIES... AT 351 PM EDT...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 2 MILES EAST OF SMITHSBURG...MOVING EAST AT 15 MPH. STORM INTENSITY IS INCREASING...AND SEVERE WEATHER MAY DEVELOP RAPIDLY. REMAIN ALERT...AND BE PREPARED TO TAKE ACTION IF WARNINGS ARE ISSUED. HEAVY RAIN WITH THIS STORM MAY REDUCE VISIBILITIES TO BELOW ONE MILE AND MAY CAUSE PONDING OF WATER ON ROADWAYS. WIND GUSTS OF 40 TO 50 MPH CAN BE EXPECTED WITH THIS STORM. && LAT...LON 3949 7730 3962 7764 3973 7757 3972 7723 TIME...MOT...LOC 1951Z 273DEG 15KT 3965 7753 KRAMAR
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 403 PM EDT MON AUG 16 2010 VAZ027-030-031-040-501-162030- RAPPAHANNOCK VA-NORTHERN FAUQUIER VA-WARREN VA-SHENANDOAH VA- CLARKE VA- 403 PM EDT MON AUG 16 2010 ...STRONG THUNDERSTORMS TO AFFECT RAPPAHANNOCK...NORTHERN FAUQUIER... WARREN...SHENANDOAH AND CLARKE COUNTIES... AT 403 PM EDT...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM OVER RIVERSIDE...MOVING EAST AT 10 MPH. HEAVY RAIN WITH THIS STORM MAY REDUCE VISIBILITIES TO BELOW ONE MILE AND MAY CAUSE PONDING OF WATER ON ROADWAYS. WIND GUSTS OF 40 TO 50 MPH CAN BE EXPECTED WITH THIS STORM. && LAT...LON 3902 7806 3882 7802 3882 7833 3896 7833 TIME...MOT...LOC 2003Z 271DEG 8KT 3891 7823 KRAMAR
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
412 PM EDT MON AUG 16 2010
MDZ003>005-162045-
WASHINGTON MD-CARROLL MD-FREDERICK MD-
412 PM EDT MON AUG 16 2010
...STRONG THUNDERSTORMS TO AFFECT WASHINGTON...CARROLL AND FREDERICK
COUNTIES...
AT 413 PM EDT...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 2 MILES
WEST OF THURMONT...MOVING EAST AT 15 MPH.
STORM INTENSITY IS INCREASING...AND SEVERE WEATHER MAY DEVELOP
RAPIDLY. REMAIN ALERT...AND BE PREPARED TO TAKE ACTION IF WARNINGS
ARE ISSUED.
WIND GUSTS IN EXCESS OF 50 MPH AND SMALL HAIL CAN BE EXPECTED WITH
THIS STORM. WINDS THIS STRONG CAN BRING DOWN LARGE TREE BRANCHES.
TAKE SHELTER UNTIL THE STORM HAS PASSED.
&&
LAT...LON 3946 7721 3959 7757 3972 7750 3973 7738
3972 7713 3972 7712
TIME...MOT...LOC 2013Z 280DEG 12KT 3963 7745
KRAMARSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 425 PM EDT MON AUG 16 2010 MDZ004-005-162100- CARROLL MD-FREDERICK MD- 425 PM EDT MON AUG 16 2010 ...STRONG THUNDERSTORMS TO AFFECT CARROLL AND FREDERICK COUNTIES... AT 426 PM EDT...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM OVER HARNEY...MOVING EAST-SOUTHEAST AT 15 MPH. HEAVY RAIN WITH THIS STORM MAY REDUCE VISIBILITIES TO BELOW ONE MILE AND MAY CAUSE PONDING OF WATER ON ROADWAYS. WIND GUSTS OF 40 TO 50 MPH CAN BE EXPECTED WITH THIS STORM. && LAT...LON 3961 7703 3969 7731 3972 7731 3973 7701 TIME...MOT...LOC 2026Z 279DEG 14KT 3972 7721 KRAMAR
The Sterling radar (KLWX), 69 km away, was scanning. The volume nearest the first event began at 20:28 UTC.
1 thunderstorm wind. Local standard time, as filed.
Uprooted and snapped trees along with large limb damage were reported near Rocky Ridge.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Maryland in 2010Every state in 2010This day in weather historyWarnings in Maryland, August 2010
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: 257035.