Slow moving showers and isolated thunderstorms moved over portions of northwestern Pennsylvania during the day on the 10th. Locally heavy rainfall caused flooding in Jefferson and Indiana counties.
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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.
Slow moving showers and isolated thunderstorms moved over portions of northwestern Pennsylvania during the day on the 10th. Locally heavy rainfall caused flooding in Jefferson and Indiana counties.
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 10, 6:35 AM EST, 1 hour 47 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 735 AM EDT SAT SEP 10 2011 .SYNOPSIS... A LARGE UPPER LOW PRESSURE SYSTEM WILL REMAIN NEAR THE OHIO VALLEY THROUGH THE WEEKEND PRODUCING CLOUDS AND SCATTERED SHOWERS. && .NEAR TERM /THROUGH TONIGHT/... ADJUSTED POPS AS AREA OF SHOWERS HAS DEVELOPED ACROSS THE I-80 CORRIDOR WITH SCATTERED SHOWERS DOWN TO PITTSBURGH. PATCHY DENSE FOG WILL LIFT TOWARD MID MORNING. WITH UPPER LOW REMAINING JUST WEST OF THE DISTRICT...A CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE ACROSS MUCH OF THE FORECAST AREA TODAY. COVERAGE OF SHOWERS WILL INCREASE DURING THE AFTERNOON AND EVENING HOURS WITH THE HEATING OF THE DAY...BUT DIMINISH AFTER SUNSET TONIGHT. && .SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/... CLOSED LOW OVER THE MIDWEST WILL EVENTUALLY OPEN UP AND DRIFT EASTWARD AS AN OPEN WAVE BY SUNDAY. THIS WILL BRING A CONTINUED CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS THROUGH THE WEEKEND WITH LITTLE CHANGE IN TEMPERATURES. && .LONG TERM /MONDAY THROUGH FRIDAY/... AREA WILL DRY OUT MONDAY AS SOUTHWEST FLOW BRINGS A BIT WARMER TEMPERATURES AHEAD OF A STRONG COLD FRONT TO CROSS THE REGION TUESDAY NIGHT. SHOWERS AND SCATTERED THUNDERSTORMS AHEAD OF AND WITH FRONT INTO WEDNESDAY FOLLOWED BY MUCH COOLER AND DRY CONDITIONS THURSDAY AND FRIDAY UNDER STRONG HIGH PRESSURE. MODELS ARE IN GOOD AGREEMENT THROUGH THE EXTENDED WITH TIMING OF FRONT AND ASSOCIATED WEATHER. TEMPERATURES CLOSE TO HPC GUIDANCE. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... SHRA/TSRA CLUSTER WHICH CROSSED FKL AND DUJ OVRNGT HAS SHIFTED NWD LEAVING A NR SATURATED BOUNDARY LYR THIS MRNG. BELT OF STRATUS THAT EXTENDED ACRS THE UPR OH WL THUS PERSIST...AND IFR CONDITIONS ARE FORECAST AT ALL PORTS EXCEPT FOR ZZV AND MGW. FOR THOSE TERMINALS...MID LEVEL CLDINESS IN ADVANCE OF NXT SHRTWV MOVING ARND CUTOFF LOW APPEARS TO BE HOLDING FOG FORMATION AT BAY. TEMPO MVFR GROUPS WERE INCLUDED FOR THOSE LOCATIONS. OVRALL PTN REPEATS TODAY DUE TO PROXIMITY OF CUTOFF UPR LOW AND DEFORMATION ZONE OVER THE UPR OHIO VALLEY. EXPECT IMPROVEMENT TO MVFR AND VFR AT MOST PORTS FOLLOWED BY SCT SHRA/TSRA FORMATION...BUT WL NOT INCLUDE A SPECIFIC MENTION AT ANY TERMINAL EXCEPT FOR FKL AND DUJ WHERE DEEPER MSTR AXIS RESIDES IN VICINITY. .OUTLOOK...SUNDAY THROUGH TUESDAY/... SUNDAY EXPECT DAYTIME VFR BRIEFLY INTERRUPTED BY MVFR SHOWERS. AT NIGHT...RESTRICTIONS CAN DEVELOP WITH LOW STRATUS / FOG. BRIEF MVFR WX POSSIBLE TUESDAY AHEAD OF THE NEXT COLD FRONT. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE PITTSBURGH PA 327 AM EDT SAT SEP 10 2011 MDZ001-OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023- 029-031-073>076-WVZ001>004-012-021>023-041-110730- 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- 327 AM EDT SAT SEP 10 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. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY. 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.
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PITTSBURGH PA
835 AM EDT SAT SEP 10 2011
PAZ016-023-101330-
INDIANA PA-JEFFERSON PA-
835 AM EDT SAT SEP 10 2011
...HEAVY RAIN WILL AFFECT NORTHEASTERN INDIANA AND SOUTHEASTERN
JEFFERSON COUNTIES...
AT 832 AM EDT...HEAVY RAIN WAS LOCATED 6 MILES NORTHEAST OF MARION
CENTER. THIS AREA OF HEAVY RAIN IS NEARLY STATIONARY.
VERY HEAVY RAIN WILL CAUSE WATER TO POND ON ROADS AND QUICKLY FILL
ROADSIDE DITCHES AND SMALL STREAMS.
SOME LOCATIONS THAT WILL BE IMPACTED INCLUDE...
MARION CENTER... GLEN CAMPBELL... CHERRY TREE...
SMICKSBURG... PUNXSUTAWNEY...
EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE ELEVATED LEVELS ON
SMALL CREEKS AND STREAMS...AND PONDING OF WATER ON COUNTRY ROADS AND
FARMLAND ALONG THE BANKS OF CREEKS AND STREAMS.
IN HILLY TERRAIN THERE ARE HUNDREDS OF LOW WATER CROSSINGS WHICH ARE
POTENTIALLY DANGEROUS IN HEAVY RAIN. DO NOT ATTEMPT TO TRAVEL ACROSS
FLOODED ROADS. FIND ALTERNATE ROUTES. IT TAKES ONLY A FEW INCHES OF
SWIFTLY FLOWING WATER TO CARRY VEHICLES AWAY.
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 SIGNIFICANT WEATHER TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...877-633-6772...WHEN YOU CAN DO SO SAFELY.
LAT...LON 4070 7881 4066 7883 4065 7884 4066 7896
4077 7918 4094 7917 4095 7880 4077 7880
4072 7880
WOODRUMThe national radar mosaic for the moment the first event began.
2 flood. Local standard time, as filed.
Trained spotter reported small streams and creeks out of their banks near Marion Center.
Emergency management reported that state route 36 is flooded south of Punxsutawney to the Indiana county border.
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, September 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: 346988, 346998.