A line of severe thunderstorms developed across western Pennsylvania ahead of a strong cold front.
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 line of severe thunderstorms developed across western Pennsylvania ahead of a strong cold front.
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 Sep 12, 8:36 AM EST, 1 hour 49 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 936 AM EDT THU SEP 12 2013 .SYNOPSIS... A STRONG COLD FRONT WILL SWEEP WARMTH AND HUMIDITY FROM THE UPPER OHIO VALLEY REGION TODAY AND PROVIDE MORE SHOWERS AND STORMS. MUCH COOLER WEATHER IS IN STORE FRIDAY AND SATURDAY BEFORE TEMPERATURES REBOUND TO NORMAL LEVELS. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPDATED FORECAST TO ACCOUNT FOR LATEST TIMING ON PCPN ASSOCIATED WITH THE FIRST COLD FRONT. LATEST DAY1 CONVECTIVE OUTLOOK BROUGHT SLIGHT RISK FARTHER SW INTO NWRN WV. WITH THE AMOUNT OF STRATUS IN A RICH ATMS...DUE NOT FORESEE WIDESPREAD SVR WX. ISOLD SVR WX APPEARS TO BE A STRETCH TOO GIVEN HOW WEAK EFFECTIVE SHEAR IS PROGGED. MEAN CLOUD LAYER IS 20KTS ALLOWING STORMS TO MOVE AT A GOOD CLIP SO ANY FLOODING WILL BE LOCALIZED...BUT PROB IN THAT IS LOW AS WELL. PREVIOUS DISCUSSION FOLLOWS: TWO FRONTS TO KEEP AN EYE ON TODAY. THE FIRST WILL MOVE THROUGH THIS MORNING AND THE SECOND LATE THIS AFTERNOON. ACTIVITY WILL DEVELOP BETWEEN THE BOUNDARIES AND MOVE EASTWARD AS THE DAY PROGRESSES. ACTIVITY TO THE WEST IS STRETCHING OUT ON THE NORTHERN SIDE OF FRONT #1. THE ACTIVITY SHOULD BLOSSOM AFTER SUNRISE AND BEGIN TO OVERSPREAD THE NORTH BETWEEN 14 AND 16Z. SHOWERS AND STORMS WILL DRIFT SOUTHWARD THROUGH THE AFTERNOON. STILL HAVE QUESTIONS ON STRENGTH OF THE ACTIVITY. ATMOSPHERE WILL BE PLENTY UNSTABLE...PARTICULARLY ACROSS THE SOUTH WITH HIGH CAPES AND LOW LI'S. FORECAST SOUNDINGS ARE NOT OVERLY IMPRESSIVE WITH K-INDEX VALUES IN THE LOW 30S AND MDPI/WINDEX AROUND .50/30-35. TIMING WILL HINDER DEVELOPMENT AS INITIALLY CONVECTIVE TEMPS ARE IN THE LOWER TO MID 80S. CONVECTIVE TEMPS DO COME DOWN TO REASONABLE VALUES BY LATE MORNING...BUT BY THEN THERE WILL ALREADY BE ACTIVITY ON GOING AND PLENTY OF CLOUD COVER. AT THIS TIME...THINK THE BEST WAY TO HANDLE WILL BE CAT SHOWER/CHC STORMS. THE VERY UNSTABLE AIR WILL BE FORCED SOUTHWARD WITH THE FIRST FRONT DURING THE AFTERNOON. BECAUSE OF THIS WOULD THINK THAT THE BEST AREA FOR STRONG/SEVERE ACTIVITY WOULD BE ACROSS THE SOUTHERN HALF OF THE AREA IN THE LATE MORNING/AFTERNOON. ALSO HAVE A FEELING THAT HEAVY RAIN COULD BE A GREATER THREAT AS MOISTURE CONVERGENCE INCREASES IN THE SOUTH AND PWATS JUMP UP TO AROUND 1.8 INCHES. SPC HAS KEPT THE AREA IN A GENERAL THUNDERSTORM...KEEPING THE SLIGHT RISK AREA TO OUR EAST. CLOUD COVER WILL BE IMPORTANT ONCE AGAIN. SOME DRIER AIR HAS SETTLED IN OVER THE OHIO VALLEY WHICH COULD ALLOW FOR SUNSHINE IN THE MORNING. WILL NEED TO KEEP CLOSE WATCH ON AMOUNT OF SUN BEFORE THE ACTIVITY REACHES THE AREA. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... FRONT WILL CLEAR THE AREA BY 00Z...WITH SOME LINGERING SHOWERS POSSIBLE ACROSS THE SOUTHEAST. DRY AIR WILL MOVE SOUTHWARD IN THE NW FLOW. MAIN TROUGH SWINGS THROUGH LATE TONIGHT WITH STRONG CAA. STRATOCU IS LIKELY TO COVER THE AREA LATE TONIGHT WITH THE COLDER AIR. TROUGH WILL REMAIN OVER THE REGION THROUGH MUCH OF FRIDAY WITH ANOTHER STRONG UPPER LEVEL WAVE MOVING SOUTHWARD ON THE WESTERN EDGE. WITH NW FLOW ACROSS THE LAKES...AND CAA CONTINUING... ISO/SCT SHOWERS COULD DEVELOP FRIDAY. BEST AREA FOR SHOWER DEVELOPMENT WOULD BE ACROSS THE NORTHERN HALF. TROUGH WILL SWING EASTWARD FRIDAY NIGHT PULLING THE COLDEST AIR OVER THE UPPER OHIO VALLEY. EXPECT CLOUDS TO HOLD ON MOST OF FRIDAY NIGHT...WITH WELL BELOW NORMAL TEMPS. RISING HEIGHTS AND SURFACE HIGH WILL ALLOW FOR A COOL AND COMFORTABLE SAT. HAVE LOWERED HIGHS ON SAT IN ACCORDANCE WITH LATEST MODEL DATA SHOWING 85H TEMPS AROUND +4. FORECAST SHOWING A MIXING LAYER UP TO AROUND 4000FT WHICH SHOULD ALLOW THE COLDER AIR TO MIX DOWN. DID NOT WANT TO GO TO LOW...AS STILL DEALING WITH AN EARLY SEPTEMBER SUN. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... THE POSITION OF HIGH PRESSURE COME DAWN SUN MRNG WILL NOT BE IDEAL FOR RADIATIONAL COOLING...BUT IT WILL BE A CHILLY NIGHT. 40S WILL BE COMMON FOR MINIMUM TEMPS WITH UPR 30S ACR DEEPER MTN VALLEYS AND N OF I-80. RETURN FLOW USHERS IN WARMER WEATHER SUNDAY INTO EARLY NEXT WEEK. THE ONE WEATHER SYSTEM TO SPEAK OF IS A MOISTURE STARVED COLD FRONT CROSSING SUN NGT INTO MON. ELECTED TO CONTINUE NO POPS FOR THIS BOUNDARY AS IT TRAVERSES. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... MAINLY MVFR CONDS IN BR/PTCHY STRATOCU WL INCR TO VFR THIS MRNG. A STG CDFNT WL MOVE ACRS THE RGN THIS AFTN WITH A ROUND OF MVFR SHWRS AND PSBL TSTMS. INCLUDED VCTS FOR SITES S OF I 80 WHERE THE BEST INSTBY IS PROGGED...ALTHOUGH STILL MENTIONED MVFR SHWRS N OF I 80. EXP A WSHFT TO THE NW AFT FROPA. THE FNT SHOULD EXIT THE RGN ERLY THIS EVE WITH SCT-BKN STRATOCU DVLPG OVRNGT. .OUTLOOK.../FRIDAY THROUGH MONDAY/... RSTRNS ARE PSBL FRI IN SCT SHWRS AS AN UPR TROF MOVES ACRS THE GT LKS...OTRW VFR CONDS EXP THRU THE PD. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && SYNOPSIS...98 NEAR TERM...98/22 SHORT TERM...22 LONG TERM...07 AVIATION...07
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE PITTSBURGH PA 1053 AM EDT THU SEP 12 2013 MDZ001-OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023- 029-031-073>076-WVZ001>004-012-021>023-041-131500- 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- 1053 AM EDT THU SEP 12 2013 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. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
838 AM EDT THU SEP 12 2013
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0655 PM TSTM WND DMG 1 ESE BETHLEHEM 40.04N 80.67W
09/11/2013 OHIO WV DEPT OF HIGHWAYS
TREES DOWN ON EAST COVE AVENUE
0659 PM TSTM WND DMG 4 ESE WEST LIBERTY 40.16N 80.53W
09/11/2013 OHIO WV DEPT OF HIGHWAYS
TREES DOWN ON CASTLEMAN RUN ROAD
&&
EVENT NUMBER PBZ1302749
EVENT NUMBER PBZ1302750
98The Pittsburgh radar (KPBZ), 10 km away, was scanning. The volume nearest the first event began at 15:25 UTC.
16 thunderstorm wind. Local standard time, as filed.
Emergency management reported a tree down on a garage.
Emergency management reported a tree down.
Emergency management reported numerous trees down.
A trained spotter reported numerous trees and power lines down.
Trees were reported down along Saxonburg BLVD and Anderson Road.
The public reported trees down.
The public reported 6 inch diameter limbs down on Heck Road.
Emergency management reported a tree down.
Emergency management reported a tree down.
The public reported trees down on White Cloud Road.
A trained spotter reported numerous large limbs down.
The 911 Call Center reported trees and power lines down along Garretts Run Road and Cherry Road.
The public reported trees down along Route 422. One tree was reported to have fallen on a house.
The 911 Call Center reported trees down.
The 911 Call Center reported trees down along Route 119.
The 911 Call Center reported trees down.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2013Every state in 2013This day in weather historyWarnings in Pennsylvania, September 2013
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: 473326, 473327, 473328, 473330, 473331, 473332, 473333, 473334, 473335, 473339, 473337, 473340, 473338, 473341, 473342, 473343.