A mesoscale convective system moved along a boundary situated over east central Ohio, southern Pennsylvania and Northern West Virginia. Severe thunderstorms across eastern Ohio, southwest Pennsylvania, northern West Virginia, and Garrett county Maryland produced widespread wind damage with 50 thousand homes left without power.
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 PBZ wrote it up.
A mesoscale convective system moved along a boundary situated over east central Ohio, southern Pennsylvania and Northern West Virginia. Severe thunderstorms across eastern Ohio, southwest Pennsylvania, northern West Virginia, and Garrett county Maryland produced widespread wind damage with 50 thousand homes left without power. The counties that were hardest hit were Belmont and Jefferson counties in Ohio, where numerous large trees blocked roadways and three large radio station towers collapsed.
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 Pittsburgh, PA wrote its last area forecast discussion before the first event at Aug 4, 1:14 PM EST, 3 hours 16 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 214 PM EDT WED AUG 4 2010 .SYNOPSIS... WARM AND HUMID CONDITIONS WILL PREVAIL THROUGH THURSDAY WITH PERIODS OF SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL BRING DRY WEATHER FOR THE CLOSE OF THE WEEK. && .NEAR TERM /THROUGH THURSDAY/... WARMTH AND HUMIDITY HAS FUELED RAPID DESTABILIZATION OF THE UPPER OHIO VALLEY ATMOSPHERE TODAY. THUNDERSTORM COMPLEX WHICH MOVED RAPIDLY ACROSS OHIO, WILL AFFECT THE REGION THROUGH THIS EVENING WITH MORE WIDESPREAD STORMS, AND BETTER SEVERE POTENTIAL OVER WESTERN, AND SOUTHERN COUNTIES WHERE INSTABILITY GRADIENT WILL FOCUS THE STORM CLUSTER. ALTHOUGH SOME HAIL REPORTS HAVE BEEN RECEIVED, THE PRIMARY SEVERE THREAT WILL COME FROM DAMAGING WIND AS WARM MID LEVELS/HIGH FREEZING LEVEL WILL INHIBIT HAIL GROWTH SOMEWHAT. THE SUPPORTING SHORTWAVE WILL SHIFT EASTWARD LATER THIS EVENING AND PRECIP PROBABILITIES WERE REDUCED TO SLIGHT NUMBERS UNTIL ADVANCING COLD FRONT REENHANCES THE POTENTIAL TOWARD MORNING. LIKELY POPS WERE CONTINUED FOR ALL ZONES ON THURSDAY ALTHOUGH QUICKER TIMING WAS USED BASED ON LATEST MODEL GUIDANCE. SEVERE POTENTIAL WAS RESTRICTED TO SOUTHERN COUNTIES WHERE INSTABILITY PARAMETER WILL HAVE A BETTER CHANCE TO RECOVER AS THURSDAY PROGRESSES. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... UPPER TROUGH/SURFACE COLD FRONT WILL COMPLETE A CROSSING OF THE UPPER OHIO ON THURSDAY NIGHT WITH NUMEROUS SHOWERS AND STORMS ENDING. HAVE PERSISTED WITH DRY FORECAST IN THE WAKE OF THE FRONT ALTHOUGH LATEST OP. NAM MODEL REIGNITES SOME SHOWERS WITH A TRAILING SHORTWAVE. THAT SCENARIO WILL HAVE TO BE WATCHED FOR THE LATE THURSDAY NIGHT AND FRIDAY TIME PERIOD. OTHERWISE, HIGH PRESSURE WILL BUILD AND PROVIDE A DRY AND COOLER WEEKEND. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... SURFACE HIGH PRESSURE WILL GRADUALLY MOVE OFF THE NEW ENGLAND COAST BY SUNDAY NIGHT WITH A RIDGE EXTENDING SOUTHWEST ACROSS THE MID ATLANTIC REGION MONDAY. DRY WEATHER IS EXPECTED TO HOLD THROUGH MONDAY. A WEAK SURFACE LOW AND COLD FRONT WILL CROSS THE GREAT LAKES BY TUESDAY AND CONTINUE SOUTHWARD ACROSS THE FORECAST AREA ON WEDNESDAY. THIS SYSTEM WILL BRING MORE CLOUD COVER AND CHANCE OF SHOWERS AND THUNDERSTORMS TUESDAY INTO WEDNESDAY. TEMPERATURES WILL BE A FEW DEGREES ABOVE NORMAL FOR THE EXTENDED PERIOD. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... MAIN AREA OF THUNDERSTORMS ASSOCIATED WITH MCS CROSSING OH WILL MOVE EAST OF OUR TERMINALS BY NIGHTFALL. OCCASIONAL IFR RESTRICTIONS CAN BE EXPECTED IN HEAVY RAIN. STRONGER STORMS COULD CONTAIN GUSTS TO 40KT AND HAIL. MVFR VISIBILITY RESTRICTIONS IN FOG AND HAZE CAN BE EXPECTED TONIGHT AFT 03Z. COVERAGE OF SHOWERS AND THUNDERSTORMS WILL INCREASE AGAIN TOWARD DAWN THURSDAY AS A COLD FRONT PUSHES INTO THE UPPER OHIO VALLEY REGION. CONDITIONS ARE FORECAST TO LOWER TO IFR AT TIMES IN PRECIPITATION AND FOG AS THE FRONT PUSHES THROUGH THURSDAY MORNING. IMPROVEMENT TO PREDOMINATELY VFR IS EXPECTED THURSDAY AFTERNOON. SATURATED GROUND AND CLEARING SKY WILL LIKELY LEAD TO FOG FORMATION DURING THE PRE-DAWN HOURS FRIDAY. VFR CONDITIONS WILL THEN PREVAIL SATURDAY THROUGH MONDAY AS HIGH PRESSURE MOVES FROM THE GREAT LAKES TO NEW ENGLAND. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && 15/14
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE PITTSBURGH PA 228 PM EDT WED AUG 4 2010 PAZ007>009-013>016-020>022-051830- MERCER-VENANGO-FOREST-LAWRENCE-BUTLER-CLARION-JEFFERSON PA-BEAVER- ALLEGHENY-ARMSTRONG- 228 PM EDT WED AUG 4 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHWEST PENNSYLVANIA...SOUTHWEST PENNSYLVANIA AND WEST CENTRAL PENNSYLVANIA. .DAY ONE...THIS AFTERNOON AND TONIGHT. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. OHZ039>041-048>050-WVZ001-051830- TUSCARAWAS-CARROLL-COLUMBIANA-COSHOCTON-HARRISON-JEFFERSON OH- HANCOCK- 228 PM EDT WED AUG 4 2010 ...SEVERE THUNDERSTORM WATCH 567 IN EFFECT UNTIL 9 PM EDT THIS EVENING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL OHIO AND NORTHERN PANHANDLE OF WEST VIRGINIA. .DAY ONE...THIS AFTERNOON AND TONIGHT. PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS. SEVERE THUNDERSTORM WATCH. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. MDZ001-PAZ023-030-032-051830- GARRETT-INDIANA-WESTMORELAND-FAYETTE- 228 PM EDT WED AUG 4 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN MARYLAND...SOUTHWEST PENNSYLVANIA AND WEST CENTRAL PENNSYLVANIA. .DAY ONE...THIS AFTERNOON AND TONIGHT. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY. THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THURSDAY. THE PRIMARY SEVERE THREATS WILL COME FROM DAMAGING WIND AND LARGE HAIL. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. OHZ057>059-068-069-PAZ029-031-WVZ002>004-012-021>023-041-051830- MUSKINGUM-GUERNSEY-BELMONT-NOBLE-MONROE-WASHINGTON-GREENE-BROOKE- OHIO-MARSHALL-WETZEL-MARION-MONONGALIA-PRESTON-TUCKER- 228 PM EDT WED AUG 4 2010 ...SEVERE THUNDERSTORM WATCH 567 IN EFFECT UNTIL 9 PM EDT THIS EVENING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL OHIO...SOUTHWEST PENNSYLVANIA...NORTHERN WEST VIRGINIA AND NORTHERN PANHANDLE OF WEST VIRGINIA. .DAY ONE...THIS AFTERNOON AND TONIGHT. PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS. SEVERE THUNDERSTORM WATCH. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY. THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THURSDAY. THE PRIMARY SEVERE THREATS WILL COME FROM DAMAGING WIND AND LARGE HAIL. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
448 PM EDT WED AUG 04 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0330 PM TSTM WND DMG WEST LAFAYETTE 40.27N 81.75W
08/04/2010 COSHOCTON OH TRAINED SPOTTER
NUMEROUS TREES AND POWER LINES DOWN.
0350 PM TSTM WND DMG BARNESVILLE 39.99N 81.17W
08/04/2010 BELMONT OH PUBLIC
NUMEROUS TREES DOWN.
0400 PM TSTM WND DMG BRIDGEPORT 40.07N 80.75W
08/04/2010 BELMONT OH PUBLIC
STRUCTURAL DAMAGE.
0400 PM HAIL ST. CLAIRSVILLE 40.08N 80.90W
08/04/2010 E1.00 INCH BELMONT OH PUBLIC
0410 PM TSTM WND DMG TILTONSVILLE 40.17N 80.70W
08/04/2010 JEFFERSON OH TRAINED SPOTTER
NUMEROUS TREES DOWN.
0410 PM TSTM WND DMG WINTERSVILLE 40.38N 80.71W
08/04/2010 JEFFERSON OH TRAINED SPOTTER
NUMEROUS TREES DOWN.
0410 PM TSTM WND DMG ST. CLAIRSVILLE 40.08N 80.90W
08/04/2010 BELMONT OH PUBLIC
ROOF BLOWN OFF.
0415 PM TSTM WND DMG MCMECHEN 39.99N 80.73W
08/04/2010 MARSHALL WV PUBLIC
STRUCTURAL DAMAGE.
0415 PM TSTM WND DMG 3 S WHEELING 40.03N 80.70W
08/04/2010 MARSHALL WV TRAINED SPOTTER
NUMEROUS TREES AND POWER LINES DOWN IN MOZART WV.
0420 PM TSTM WND DMG WHEELING 40.08N 80.70W
08/04/2010 OHIO WV PUBLIC
NUMEROUS TREES DOWN.
&&SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PITTSBURGH PA
450 PM EDT WED AUG 4 2010
PAZ023-042115-
INDIANA PA-
450 PM EDT WED AUG 4 2010
...THUNDERSTORMS...
THUNDERSTORMS TO MOVE THROUGH THE FOLLOWING COUNTY...
INDIANA...
AT 449 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR IN PITTSBURGH
INDICATED STRONG THUNDERSTORMS OVER ARMAGH...MOVING EAST AT 35 MPH.
THESE STORMS WILL BE CAPABLE OF PRODUCING WIND GUSTS TO 45 MPH...IN
ADDITION TO SMALL HAIL.
SOME LOCATIONS THAT WILL BE IMPACTED BY THESE STORMS INCLUDE...
ARMAGH...
KEEP AN EYE TO THE SKY AND MOVE TO A SAFE PLACE IF THUNDERSTORMS
APPROACH.
PLEASE REPORT HAIL...STRONG WINDS OR WIND DAMAGE TO THE NATIONAL
WEATHER SERVICE BY CALLING TOLL FREE...1-877-633-6772.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT
WEDNESDAY EVENING FOR WESTERN MARYLAND AND EAST CENTRAL OHIO AND
SOUTHWEST PENNSYLVANIA AND NORTHERN WEST VIRGINIA.
&&
LAT...LON 4040 7898 4042 7903 4039 7905 4038 7907
4039 7913 4040 7913 4039 7914 4039 7916
4057 7912 4055 7889SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE PITTSBURGH PA 503 PM EDT WED AUG 4 2010 PAZ022-023-030-042130- ARMSTRONG PA-INDIANA PA-WESTMORELAND PA- 503 PM EDT WED AUG 4 2010 ...THUNDERSTORMS... THUNDERSTORMS TO MOVE THROUGH THE FOLLOWING COUNTIES... ARMSTRONG...WESTMORELAND AND INDIANA... AT 458 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR IN PITTSBURGH INDICATED STRONG THUNDERSTORMS 7 MILES EAST OF APOLLO...OR ABOUT 7 MILES EAST OF VANDERGRIFT...MOVING SOUTHEAST AT 30 MPH. THESE STORMS WILL BE CAPABLE OF PRODUCING WIND GUSTS TO 45 MPH...IN ADDITION TO SMALL HAIL. SOME LOCATIONS THAT WILL BE IMPACTED BY THESE STORMS INCLUDE... APOLLO... SALTSBURG... BLAIRSVILLE... NEW FLORENCE... LIGONIER... DERRY... KEEP AN EYE TO THE SKY AND MOVE TO A SAFE PLACE IF THUNDERSTORMS APPROACH. PLEASE REPORT HAIL...STRONG WINDS OR WIND DAMAGE TO THE NATIONAL WEATHER SERVICE BY CALLING TOLL FREE...1-877-633-6772. PRECAUTIONARY/PREPAREDNESS ACTIONS... A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT WEDNESDAY EVENING FOR WESTERN MARYLAND AND EAST CENTRAL OHIO AND SOUTHWEST PENNSYLVANIA AND NORTHERN WEST VIRGINIA. && LAT...LON 4040 7898 4023 7925 4058 7957 4070 7938
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
508 PM EDT WED AUG 04 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0442 PM TSTM WND DMG FAIRMONT 39.48N 80.15W
08/04/2010 MARION WV PUBLIC
TREES DOWN
&&
15SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE PITTSBURGH PA 514 PM EDT WED AUG 4 2010 PAZ015-016-022-023-042145- ARMSTRONG PA-CLARION PA-INDIANA PA-JEFFERSON PA- 514 PM EDT WED AUG 4 2010 ...HEAVY RAIN... SHOWERS AND THUNDERSTORMS WITH HEAVY RAIN TO MOVE THROUGH THE FOLLOWING COUNTIES...ARMSTRONG...INDIANA...JEFFERSON AND CLARION... AT 512 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR IN PITTSBURGH SHOWED STORMS WITH HEAVY RAIN 5 MILES NORTHWEST OF DORA...MOVING EAST AT 35 MPH. THESE SHOWERS CAN PRODUCE HEAVY RAIN THAT MAY CAUSE PONDED WATER ON ROADS AND IN LOW LYING AREAS. VISIBILITY CAN BE REDUCED. SOME LOCATIONS THAT WILL BE IMPACTED BY THESE SHOWERS INCLUDE... SUMMERVILLE... NEW BETHLEHEM... DORA... BROOKVILLE... PUNXSUTAWNEY... REYNOLDSVILLE... DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS SAFELY. MOVE TO HIGHER GROUND. PLEASE REPORT HEAVY RAIN AND FLOODING PROBLEMS TO THE NATIONAL WEATHER SERVICE BY CALLING TOLL FREE...1-877-633-6772. PRECAUTIONARY/PREPAREDNESS ACTIONS... A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT WEDNESDAY EVENING FOR WESTERN MARYLAND AND EAST CENTRAL OHIO AND SOUTHWEST PENNSYLVANIA AND NORTHERN WEST VIRGINIA. && LAT...LON 4093 7939 4119 7929 4114 7879 4084 7880
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
528 PM EDT WED AUG 04 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0500 PM TSTM WND DMG 1 S ISABELLA 39.94N 79.93W
08/04/2010 FAYETTE PA EMERGENCY MNGR
ROOF WAS BLOWN OFF HOUSE NEAR EAST RIVERSIDE...BETWEEN
MASONTOWN AND BROWNSVILLE.
&&
15The Pittsburgh radar (KPBZ), 119 km away, was scanning. The volume nearest the first event began at 21:30 UTC.
3 thunderstorm wind. Local standard time, as filed.
Emergency management reported numerous trees, power poles and power lines down in Friendsville.
Emergency management reported numerous trees, power poles and power lines down near Accident.
Emergency management reported numerous trees, power poles and power lines down in and around Deep Creek Lake Park.
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: 257812, 257813, 257815.