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, 2 hours 6 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.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE PITTSBURGH PA 1107 AM EDT WED AUG 4 2010 OHZ039>041-048>050-057>059-068-069-PAZ007-013-014-020>022-029-031- WVZ001>004-012-021-022-042115- TUSCARAWAS-CARROLL-COLUMBIANA-COSHOCTON-HARRISON-JEFFERSON OH- MUSKINGUM-GUERNSEY-BELMONT-NOBLE-MONROE-MERCER-LAWRENCE-BUTLER- BEAVER-ALLEGHENY-ARMSTRONG-WASHINGTON-GREENE-HANCOCK-BROOKE-OHIO- MARSHALL-WETZEL-MARION-MONONGALIA- INCLUDING THE CITIES OF...NEW PHILADELPHIA...DOVER... UHRICHSVILLE...CARROLLTON...EAST LIVERPOOL...SALEM...COLUMBIANA... EAST PALESTINE...WELLSVILLE...CALCUTTA...COSHOCTON...CADIZ... HOPEDALE...STEUBENVILLE...ZANESVILLE...CAMBRIDGE... MARTINS FERRY...ST. CLAIRSVILLE...BELLAIRE...BARNESVILLE... SHADYSIDE...BRIDGEPORT...CALDWELL...WOODSFIELD...SHARON... HERMITAGE...GROVE CITY...GREENVILLE...FARRELL...NEW CASTLE... ELLWOOD CITY...BUTLER...ZELIENOPLE...ALIQUIPPA...BEAVER FALLS... AMBRIDGE...MONACA...BEAVER...PITTSBURGH METRO AREA...KITTANNING... FORD CITY...LEECHBURG...FREEPORT...APOLLO...WASHINGTON... CANONSBURG...DONORA...CALIFORNIA...CHARLEROI...MONONGAHELA... MCMURRAY...WAYNESBURG...FAIRDALE...TORONTO...WEIRTON...WHEELING... MOUNDSVILLE...NEW MARTINSVILLE...FAIRMONT...MORGANTOWN 1107 AM EDT WED AUG 4 2010 ...HOT AND HUMID WEATHER TODAY... THE NATIONAL WEATHER SERVICE ADVISES CAUTION TODAY FOR ANYONE INVOLVED IN OUTDOOR ACTIVITIES AS HEAT INDEX VALUES WILL RISE INTO THE MID AND UPPER 90S. HIGH TEMPERATURES NEAR 90 ARE FORECAST ALONG WITH HIGH HUMIDITY. THE HEAT INDEX...ALSO KNOWN AS THE APPARENT TEMPERATURE...CONSIDERS THE EFFECTS OF BOTH HEAT AND HUMIDITY ON THE HUMAN BODY. WHEN HEAT INDEX VALUES REACH INTO THE 90S...ITS WISE TO SLOW DOWN AND DRINK PLENTY OF WATER WHEN OUTDOORS. WEAR LOOSE FITTING AND LIGHT COLORED CLOTHES. CONSIDER SPENDING MORE TIME IN AN AIR CONDITIONED BUILDING. STAY COOL AND LISTEN FOR FURTHER UPDATES ON THIS WEEKS HEAT AND HUMIDITY FROM THE NATIONAL WEATHER SERVICE. 15
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE PITTSBURGH PA 200 PM EDT WED AUG 4 2010 OHZ039>041-048>050-057>059-068-069-041930- TUSCARAWAS-CARROLL-COLUMBIANA-COSHOCTON-HARRISON-JEFFERSON OH- MUSKINGUM-GUERNSEY-BELMONT-NOBLE-MONROE- INCLUDING THE CITIES OF...NEW PHILADELPHIA...DOVER... UHRICHSVILLE...CARROLLTON...EAST LIVERPOOL...SALEM...COLUMBIANA... EAST PALESTINE...WELLSVILLE...CALCUTTA...COSHOCTON...CADIZ... HOPEDALE...STEUBENVILLE...ZANESVILLE...CAMBRIDGE... MARTINS FERRY...ST. CLAIRSVILLE...BELLAIRE...BARNESVILLE... SHADYSIDE...BRIDGEPORT...CALDWELL...WOODSFIELD 200 PM EDT WED AUG 4 2010 ...THUNDERSTORMS APPROACHING FROM THE NORTHWEST... SCATTERED THUNDERSTORMS WILL BE APPROACHING EASTERN OHIO FROM THE NORTHWEST BY 3PM. THESE THUNDERSTORMS WILL BE CAPABLE OF PRODUCING GUSTY WINDS AND LARGE HAIL. KEEP THIS IN MIND WHEN PLANNING AFTERNOON ACTIVITIES. CONDITIONS ARE EXPECTED TO REMAIN HOT AND HUMID THIS AFTERNOON IN ADVANCE OF THE THUNDERSTORMS. BE MINDFUL OF HEAT INDEX VALUES IN THE 90S.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE PITTSBURGH PA 311 PM EDT WED AUG 4 2010 PAZ014>016-022-023-042015- ARMSTRONG PA-BUTLER PA-CLARION PA-INDIANA PA-JEFFERSON PA- 311 PM EDT WED AUG 4 2010 ...THUNDERSTORMS... THUNDERSTORMS TO MOVE THROUGH THE FOLLOWING COUNTIES... ARMSTRONG...INDIANA...BUTLER...JEFFERSON AND CLARION... AT 309 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR IN PITTSBURGH INDICATED STRONG THUNDERSTORMS 7 MILES NORTHWEST OF BUTLER...OR ABOUT 6 MILES EAST OF MORAINE STATE PARK...MOVING EAST AT 35 MPH. THESE STORMS WILL BE CAPABLE OF PRODUCING WIND GUSTS TO 40 MPH. SOME LOCATIONS THAT WILL BE IMPACTED BY THESE STORMS INCLUDE... BUTLER... HOOKER... CHICORA... BRADYS BEND... EAST BRADY... KITTANNING... FORD CITY... CROOKED CREEK LAKE PARK... NEW BETHLEHEM... MUFF... ELDERTON... SHELOCTA... 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 EAST CENTRAL OHIO AND SOUTHWEST PENNSYLVANIA AND NORTHERN WEST VIRGINIA. && LAT...LON 4099 7901 4049 7915 4087 8008 4105 8004
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
321 PM EDT WED AUG 04 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0309 PM TSTM WND DMG PHILO 39.86N 81.91W
08/04/2010 MUSKINGUM OH TRAINED SPOTTER
SPOTTER IN PHILO REPORTED NUMEROUS TREES AND POWER LINES
DOWN.
0255 PM TSTM WND DMG 3 S COSHOCTON 40.22N 81.85W
08/04/2010 COSHOCTON OH PUBLIC
WIDESPREAD TREE DAMAGE WITH LARGE LIMBS DOWN.
&&
15SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE PITTSBURGH PA 407 PM EDT WED AUG 4 2010 PAZ007-008-013>015-022-042030- ARMSTRONG PA-BUTLER PA-CLARION PA-LAWRENCE PA-MERCER PA-VENANGO PA- 407 PM EDT WED AUG 4 2010 ...THUNDERSTORMS... THUNDERSTORMS TO MOVE THROUGH THE FOLLOWING COUNTIES... ARMSTRONG...BUTLER...VENANGO...CLARION...MERCER AND LAWRENCE... AT 403 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR IN PITTSBURGH INDICATED STRONG THUNDERSTORMS 4 MILES NORTHEAST OF SLIPPERY ROCK...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... SLIPPERY ROCK... GROVE CITY... CLINTONVILLE... HOOKER... EAU CLAIRE... EMLENTON... EAST BRADY... CHICORA... BRADYS BEND... 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 EAST CENTRAL OHIO AND SOUTHWEST PENNSYLVANIA AND NORTHERN WEST VIRGINIA. && LAT...LON 4120 7951 4090 7959 4101 8015 4121 8009
The Pittsburgh radar (KPBZ), 54 km away, was scanning. The volume nearest the first event began at 20:22 UTC.
9 thunderstorm wind. Local standard time, as filed.
The public reported numerous trees down in West Alexander.
Emergency management reported roof damage to a house near Isabella.
A trained spotter reported numerous trees down in Donora.
The public reported large trees down in Charleroi.
An off duty NWS employee reported numerous trees and power lines down along State Route 40 near Hopwood.
A trained spotter reported numerous trees down along State Route 51 near Belle Vernon.
A trained spotter reported numerous trees and power lines down in Monessen.
A trained spotter reported numerous trees down in Farmington.
Emergency management reported trees down in Heathville.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2010Every state in 2010This day in weather historyWarnings in Pennsylvania, 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: 257799, 257801, 257802, 257803, 257805, 257806, 257807, 257808, 257809.