Ahead of a slow moving cold front scattered severe thunderstorms developed in an unstable airmass across western Pennsylvania and northern West Virginia.
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.
Ahead of a slow moving cold front scattered severe thunderstorms developed in an unstable airmass across western Pennsylvania and northern West Virginia.
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 Apr 26, 10:20 AM EST, 2 hours 20 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 1120 AM EDT TUE APR 26 2011 .SYNOPSIS... SOUTHWEST FLOW ALOFT WILL CONTINUE TO PROVIDE ABOVE NORMAL TEMPERATURES ALONG WITH AFTERNOON AND EVENING THUNDERSTORMS THROUGH WEDNESDAY. A COLD FRONT WILL PUSH ACROSS THE DISTRICT THURSDAY BRINGING COOLER TEMPERATURES AND DRIER WEATHER. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SCATTERED ACTIVITY WILL BE ACROSS THE REGION THIS MORNING WITH LOW CHANCE POPS. NEXT SHORTWAVE OVER THE LOWER OHIO VALLEY WILL ARRIVE FOR THE AFTERNOON WITH MORE WIDESPREAD COVERAGE OF SHOWERS AND STORMS. SEVERE POTENTIAL WILL EXIST AGAIN WITH INSTABILITY AND DEEP LAYER SHEAR. TEMPERATURES SURGING WITH SUNSHINE LATE THIS MORNING AND WITH SOUTHERLY FLOW RAISED NEARLY 5 DEGREES. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... UPPER TROF WILL BE MOVING EAST ACROSS THE CENTRAL PLAINS TO THE OHIO VALLEY THROUGH THURSDAY WITH PERIODS OF SHOWERS AND STORMS AND POTENTIAL SEVERE EACH PERIOD DEPENDING ON TIMING OF INDIVIDUAL SHORTWAVES AHEAD OF TROF. ON THURSDAY MAIN UPPER TROF AND COLD FRONT WILL SWEEP ACROSS REGION WITH COOLER TEMPERATURES WORKING IN BEHIND THE FRONT DURING THE AFTERNOON. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... THE FORECAST PERIOD BEGINS WITH REASONABLE GFS/ECMWF/GFSE AGREEMENT THAT A CLOSED LOW WILL BE LOCATED ACROSS THE NORTHERN GREAT LAKES WITH A TROUGH ACROSS THE OHIO VALLEY. WITH THE PASSAGE OF THE TROUGH, THERE IS THE CHANCE OF SHOWERS THURSDAY NIGHT INTO EARLY FRIDAY. HIGH PRESSURE WILL THEN BUILD IN FROM THE SOUTHWEST ON FRIDAY WITH MID-LEVEL RIDGING BUILDING IN THROUGH SATURDAY NIGHT. CLOUD COVERAGE WILL DECREASE WITH A MOSTLY SUNNY AND DRY FORECAST LATE FRIDAY INTO SATURDAY. TEMPS WILL BE NEAR NORMAL VALUES THROUGH THIS PERIOD. THERE IS LESS MODEL CERTAINTY WITH THE TIMING OF A COLD FRONT AS THE NEXT TROUGH CROSSES THE OHIO VALLEY FOR THE LATE WEEKEND INTO EARLY NEXT WEEK. THE 12Z GFS IS MUCH FASTER WITH THIS FEATURE, BRINGING THE COLD FRONT ACROSS THE AREA EARLY ON SUNDAY WHILE THE 00Z ECMWF DOES NOT BRING THE FRONT ACROSS THE AREA UNTIL MONDAY AFTERNOON. THE FORECAST LEANS CLOSER TO THE SLOWER AND THUS WARMER ECMWF. CHANCE POPS ARE FORECAST SUNDAY AND MONDAY WITH TEMPS AROUND 5 TO 10 DEGREES ABOVE NORMAL AHEAD OF THE FRONT. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... GENERALLY VFR CONDITIONS CAN BE EXPECTED INTO EARLY AFTERNOON WITH BROKEN CIRRUS AND SCT CU DURING THE AFTERNOON. MODELS ARE INDICATING THAT A LINE OF -RW/-TRW WILL MOVE THROUGH DURING THE AFTERNOON AS THE ATMOSPHERE DESTABILIZES AND AN UL WAVE SWINGS ACROSS THE UPPER OHIO VALLEY AND THIS WILL BRING THE BEST CHANCE OF RESTRICTIONS. SFC WINDS WILL INCREASE THIS MORNING WITH STRONG ATMOSPHERIC MIXING. EXPECT SOUTH WINDS OF 20 TO 25 KTS BY LATE MORNING AND THROUGH THE AFTERNOON HOURS. EXPECT ACTIVITY TO QUICKLY WIND DOWN AFTER SUNSET, FOLLOWED BY GENERAL VFR CONDITIONS AND LIGHTER WINDS. A COLD FRONT WILL APPROACH FROM THE WEST WEDNESDAY AND CROSS THE REGION BY THURSDAY. EXPECT PERIODS OF SHOWERS AND RESTRICTIONS, WITH GREATER COVERAGE LATE WEDNESDAY AFTERNOON INTO THURSDAY ALONG/IMMEDIATELY IN THE WAKE OF THE COLD FRONT. RESIDUAL SHOWERS AND RESTRICTIONS ARE LIKELY LATE THURSDAY INTO FRIDAY AS UPPER LEVEL LOW PRESSURE GRADUALLY EXITS TO THE NORTHEAST. HIGH PRESSURE AND VFR ARE EXPECTED TO RETURN TO THE AREA FRIDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE PITTSBURGH PA 418 AM EDT TUE APR 26 2011 MDZ001-OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023- 029-031-073>076-WVZ001>004-012-021>023-041-270830- GARRETT-TUSCARAWAS-CARROLL-COLUMBIANA-COSHOCTON-HARRISON- JEFFERSON OH-MUSKINGUM-GUERNSEY-BELMONT-NOBLE-MONROE-MERCER-VENANGO- FOREST-LAWRENCE-BUTLER-CLARION-JEFFERSON PA-BEAVER-ALLEGHENY- ARMSTRONG-INDIANA-WASHINGTON-GREENE-WESTMORELAND-WESTMORELAND RIDGES- FAYETTE-FAYETTE RIDGES-HANCOCK-BROOKE-OHIO-MARSHALL-WETZEL-MARION- MONONGALIA-PRESTON-TUCKER- 418 AM EDT TUE APR 26 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN MARYLAND...EAST CENTRAL OHIO...NORTHWEST PENNSYLVANIA...SOUTHWEST PENNSYLVANIA...WEST CENTRAL PENNSYLVANIA...NORTHERN WEST VIRGINIA AND NORTHERN PANHANDLE OF WEST VIRGINIA. .DAY ONE...TODAY AND TONIGHT. THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS THIS AFTERNOON AND THIS EVENING. THE PRIMARY SEVERE THREAT WILL BE DAMAGING THUNDERSTORM WINDS AND LARGE HAIL. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY. THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS WEDNESDAY AND WEDNESDAY EVENING. THE PRIMARY SEVERE THREAT WILL BE DAMAGING THUNDERSTORM WINDS 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 816 AM EDT TUE APR 26 2011 PAZ008-009-014-015-022-261300- ARMSTRONG PA-BUTLER PA-CLARION PA-FOREST PA-VENANGO PA- 816 AM EDT TUE APR 26 2011 ...THUNDERSTORMS... THUNDERSTORMS TO MOVE THROUGH THE FOLLOWING COUNTIES... ARMSTRONG...BUTLER...VENANGO...FOREST AND CLARION... AT 814 AM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR IN PITTSBURGH INDICATED STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 4 MILES SOUTHWEST OF SENECA TO 5 MILES SOUTH OF EMLENTON...MOVING EAST AT 45 MPH. SOME LOCATIONS THAT WILL BE IMPACTED BY THESE STORMS INCLUDE... EMLENTON... OIL CITY... SENECA... VAN... KNOX... TIONESTA... FRYBURG... 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. LAT...LON 4158 7947 4109 7937 4106 7970 4142 7983
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PITTSBURGH PA
847 AM EDT TUE APR 26 2011
PAZ009-015-016-261330-
CLARION PA-FOREST PA-JEFFERSON PA-
847 AM EDT TUE APR 26 2011
...THUNDERSTORMS...
THUNDERSTORMS TO MOVE THROUGH THE FOLLOWING COUNTIES...
JEFFERSON...FOREST AND CLARION...
AT 843 AM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR IN PITTSBURGH
INDICATED STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM
TRUNKEYVILLE TO 7 MILES SOUTHWEST OF COOK FOREST STATE PARK...OR
ALONG A LINE EXTENDING FROM 2 MILES NORTH OF WEST HICKORY TO 6 MILES
NORTHEAST OF CLARION...MOVING EAST AT 45 MPH.
SOME LOCATIONS THAT WILL BE IMPACTED BY THESE STORMS INCLUDE...
WEST HICKORY... FRYBURG... KELLETTVILLE...
COOK FOREST STATE PARK... REDCLYFFE...
BALLTOWN... MARIENVILLE...
CLEAR CREEK STATE PARK... LYNCH...
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.
LAT...LON 4144 7895 4143 7898 4144 7899 4144 7906
4142 7907 4141 7908 4136 7909 4136 7903
4138 7896 4136 7892 4132 7892 4125 7944
4163 7943 4163 7896PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
1005 AM EDT TUE APR 26 2011
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0700 PM TSTM WND DMG TEMPLETON 40.92N 79.46W
04/25/2011 ARMSTRONG PA EMERGENCY MNGR
13 STRUCTURES DAMAGED...WITH NUMEROURS LARGE TREES
REPORTED DOWN
&&
EVENT NUMBER PBZ1100671
JDPRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE PITTSBURGH PA
1041 AM EDT TUE APR 26 2011
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0700 PM TSTM WND DMG TEMPLETON 40.92N 79.46W
04/25/2011 ARMSTRONG PA EMERGENCY MNGR
13 STRUCTURES DAMAGED...WITH NUMEROUS LARGE TREES
REPORTED DOWN
&&
CORRECTED REMARKS
EVENT NUMBER PBZ1100671
JDSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE PITTSBURGH PA 1155 AM EDT TUE APR 26 2011 OHZ039-048-057-058-068-261800- TUSCARAWAS-COSHOCTON-MUSKINGUM-GUERNSEY-NOBLE- INCLUDING THE CITIES OF...NEW PHILADELPHIA...DOVER... UHRICHSVILLE...COSHOCTON...ZANESVILLE...CAMBRIDGE...CALDWELL 1155 AM EDT TUE APR 26 2011 ...THUNDERSTORMS WITH GUSTY WINDS POSSIBLE THIS AFTERNOON... THE NATIONAL WEATHER SERVICE ADVISES THAT THUNDERSTORMS WITH POTENTIALLY STRONG WIND GUSTS CAN BE MOVING EASTWARD THROUGH THESE EAST CENTRAL OHIO COUNTIES BETWEEN 1 AND 3 PM. THERE MAY ALSO BE HAIL AND A BRIEF PERIOD OF HEAVY RAIN AND FREQUENT LIGHTNING. WHEN THUNDERSTORMS THREATEN...ITS SAFEST TO GO INDOORS...PREFERABLY IN A STRONG STRUCTURE TO BEST PROTECT YOURSELF FROM STRONG THUNDERSTORM WINDS. AFTERNOON TRAVELERS CAN BE AFFECTED. PLEASE REPORT STRONG WINDS AND HAIL AND ANY RELATED WEATHER PROBLEMS TO THE NATIONAL WEATHER SERVICE BY CALLING TOLL FREE...1-877-633-6772. OHZ040-041-049-050-059-069-WVZ001>004-012-261800- CARROLL-COLUMBIANA-HARRISON-JEFFERSON OH-BELMONT-MONROE-HANCOCK- BROOKE-OHIO-MARSHALL-WETZEL- INCLUDING THE CITIES OF...CARROLLTON...EAST LIVERPOOL...SALEM... COLUMBIANA...EAST PALESTINE...WELLSVILLE...CALCUTTA...CADIZ... HOPEDALE...STEUBENVILLE...MARTINS FERRY...ST. CLAIRSVILLE... BELLAIRE...BARNESVILLE...SHADYSIDE...BRIDGEPORT...WOODSFIELD... TORONTO...WEIRTON...WHEELING...MOUNDSVILLE...NEW MARTINSVILLE 1155 AM EDT TUE APR 26 2011 ...THUNDERSTORMS WITH GUSTY WINDS POSSIBLE LATE THIS AFTERNOON... THE NATIONAL WEATHER SERVICE ADVISES THAT THUNDERSTORMS WITH POTENTIALLY STRONG WIND GUSTS CAN BE MOVING EASTWARD THROUGH THESE OHIO VALLEY COUNTIES BETWEEN 2 AND 5 PM. THERE MAY ALSO BE HAIL AND A BRIEF PERIOD OF HEAVY RAIN AND FREQUENT LIGHTNING. AFTERNOON TRAVELERS AND EVENING COMMUTERS CAN BE AFFECTED. WHEN THUNDERSTORMS THREATEN...ITS SAFEST TO GO INDOORS...PREFERABLY IN A STRONG STRUCTURE TO BEST PROTECT YOURSELF FROM STRONG THUNDERSTORM WINDS. PLEASE REPORT STRONG WINDS AND HAIL AND ANY RELATED WEATHER PROBLEMS TO THE NATIONAL WEATHER SERVICE BY CALLING TOLL FREE...1-877-633-6772. PAZ007-008-013-014-020-021-029-031-WVZ021-022-261800- MERCER-VENANGO-LAWRENCE-BUTLER-BEAVER-ALLEGHENY-WASHINGTON-GREENE- MARION-MONONGALIA- INCLUDING THE CITIES OF...SHARON...HERMITAGE...GROVE CITY... GREENVILLE...FARRELL...OIL CITY...FRANKLIN...SUGARCREEK... NEW CASTLE...ELLWOOD CITY...BUTLER...ZELIENOPLE...ALIQUIPPA... BEAVER FALLS...AMBRIDGE...MONACA...BEAVER... PITTSBURGH METRO AREA...WASHINGTON...CANONSBURG...DONORA... CALIFORNIA...CHARLEROI...MONONGAHELA...MCMURRAY...WAYNESBURG... FAIRDALE...FAIRMONT...MORGANTOWN 1155 AM EDT TUE APR 26 2011 ...THUNDERSTORMS WITH GUSTY WINDS POSSIBLE LATE THIS AFTERNOON... THE NATIONAL WEATHER SERVICE ADVISES THAT THUNDERSTORMS WITH POTENTIALLY STRONG WIND GUSTS CAN BE MOVING EASTWARD THROUGH THE PITTSBURGH METRO AREA AND THE INTERSTATE 79 CORRIDOR BETWEEN 3 AND 6 PM. THERE MAY ALSO BE HAIL AND A BRIEF PERIOD OF HEAVY RAIN AND FREQUENT LIGHTNING. EVENING COMMUTERS CAN BE AFFECTED. WHEN THUNDERSTORMS THREATEN...ITS SAFEST TO GO INDOORS...PREFERABLY IN A STRONG STRUCTURE TO BEST PROTECT YOURSELF FROM STRONG THUNDERSTORM WINDS. PLEASE REPORT STRONG WINDS AND HAIL AND ANY RELATED WEATHER PROBLEMS TO THE NATIONAL WEATHER SERVICE BY CALLING TOLL FREE...1-877-633-6772.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE PITTSBURGH PA 1231 PM EDT TUE APR 26 2011 OHZ059-PAZ020-021-029-WVZ002>004-261730- ALLEGHENY PA-BEAVER PA-BELMONT OH-BROOKE WV-MARSHALL WV-OHIO WV-WASHINGTON PA- 1231 PM EDT TUE APR 26 2011 ...THUNDERSTORMS WITH GUSTY WINDS AND SMALL HAIL TO MOVE THROUGH THE FOLLOWING COUNTIES...BELMONT...WASHINGTON...ALLEGHENY...BEAVER... MARSHALL...OHIO AND BROOKE... AT 1225 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR IN PITTSBURGH INDICATED STRONG THUNDERSTORMS OVER VALLEY GROVE...MOVING NORTHEAST AT 50 MPH. THIS STORM MAY PRODUCE DIME SIZE HAIL AND WIND GUSTS TO 45 MPH. SOME LOCATIONS THAT WILL BE IMPACTED BY THESE STORMS INCLUDE... WINDSOR HEIGHTS... WEST LIBERTY... WARWOOD... VALLEY GROVE... CLEARVIEW... BETHANY... FRANKLIN... AVELLA... BURGETTSTOWN... FLORENCE... MCDONALD... RACCOON CREEK STATE PARK... 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. LAT...LON 4073 8027 4056 8000 4002 8052 4012 8072
The Pittsburgh radar (KPBZ), 37 km away, was scanning. The volume nearest the first event began at 17:41 UTC.
8 thunderstorm wind, 2 hail. Local standard time, as filed.
Emergency management reported multiple trees down in Penn Township.
Emergency management reported trees down in Monongahela.
Emergency management reported trees down near Starr Junction.
Emergency management reported trees down in Greensburg.
A wind gust to 64 MPH was recorded at the Latrobe Airport.
Emergency management reported trees down in Ligonier.
Emergency management reported large branches down in Homer City.
A trained spotter reported a large tree down in Strongstown.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2011Every state in 2011This day in weather historyWarnings in Pennsylvania, April 2011
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: 295654, 295651, 295655, 295656, 295653, 295657, 295662, 295658, 295659, 295660.