Isolated showers and thunderstorms developed in the afternoon of August 31st with the help of a departing shortwave.
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.
Isolated showers and thunderstorms developed in the afternoon of August 31st with the help of a departing shortwave.
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 31, 2:21 PM EST, 2 hours 54 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 321 PM EDT SAT AUG 31 2013 .SYNOPSIS... WARM AND HUMID CONDITIONS WITH PERIODIC SHOWERS AND THUNDERSTORMS WILL PREVAIL THROUGH THE LABOR DAY WEEKEND. && .NEAR TERM /THROUGH SUNDAY/... AS OF MID-AFTERNOON...CONVECTION HAS GENERALLY BEEN A BUST SO FAR. EXCEPT FOR A FEW ISOLATED SHOWERS ALONG THE INTERSTATE 80 CORRIDOR...ALL LOCATIONS HAVE REMAINED DRY SINCE MID-MORNING. CONSIDERING THE MAIN UPPER LEVEL SHORTWAVE HAS ALREADY PUSHED EAST OF THE REGION...DO NOT REALLY SEE ANYTHING THAT WILL PROVIDE MUCH OF A FORCING MECHANISM UNTIL THE NEXT SHORTWAVE AFFECTING THE AREA LATE TONIGHT INTO SUNDAY. AS A RESULT...HAVE CUT WAY BACK ON POPS EARLY...RAMPING THEM UP AGAIN BY LATE TONIGHT. HOWEVER...CANNOT COMPLETELY DISCOUNT THE POSSIBILITY OF A LINE OF SHOWERS/STORMS DEVELOPING FROM NORTHEAST TO SOUTHWEST ACROSS THE REGION WHICH SEVERAL RUNS OF THE HRRR HAS BEEN INSISTENT WILL DEVELOP JUST BEFORE SUNSET. ANOTHER STICKY NIGHT CAN BE EXPECTED WITH LOWS ONLY DROPPING TO AROUND 70. A BIT OF DISAGREEMENT BETWEEN MODELS FOR TOMORROWS FORECAST. ALL OF THE SYNOPTIC MODELS BRING A DECENT SHORTWAVE FROM EASTERN OHIO IN THE MORNING TO CENTRAL PENNSYLVANIA BY THE AFTERNOON...TRIGGERING WIDESPREAD PRECIPITATION. ON THE OTHER HAND...ALL OF THE HIGH RESOLUTION MODELS SHOW MUCH LESS COVERAGE WITH PRECIP. SEEING AS THE SHORTWAVE IN QUESTION IS CURRENTLY OVER CHICAGO PRODUCING SHOWERS AND THUNDERSTORMS...WILL STICK WITH THE SYNOPTIC MODEL SOLUTIONS. A SCENARIO SIMILAR TO TODAY COULD OCCUR...WITH THE HIGHEST POPS POTENTIALLY ARRIVING IN THE MORNING ACROSS WESTERN PORTIONS OF THE AREA ALONG WITH THE SHORTWAVE AND REMNANT THUNDERSTORMS. HOWEVER...WILL PUT IN LIKELY POPS ALONG THE RIDGES DURING THE EARLY AFTERNOON WHILE THE SHORTWAVE IS PASSING THROUGH. && .SHORT TERM /SUNDAY NIGHT THROUGH MONDAY/... THERE SHOULD BE A BRIEF LULL IN PRECIPITATION SUNDAY EVENING WITH THE UPPER LEVEL SHORTWAVE TO THE EAST AND THE NEXT COLD FRONT OUT TO THE WEST. RAIN SHOULD BEGIN TO OVERTAKE THE EASTERN COUNTIES VERY EARLY MONDAY...AND THE FRONT WILL BE HUGGING THE RIDGES BY MONDAY EVENING. INSTABILITY AND WIND SHEAR SHOULD BE HIGH ENOUGH THAT A FEW STRONGER THUNDERSTORMS ARE POSSIBLE...BUT OVERALL SEVERE THREAT APPEARS TO BE LOW.TEMPERATURES SUNDAY NIGHT AND MONDAY SHOULD BE SIMILAR TO THOSE THROUGH THE EARLIER PORTIONS OF THE WEEKEND. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... THE CDFNT IS FORECAST TO EXIT THE RGN MON NGT AND END THE SHWR CHCS. BLDG HIGH PRES SHOULD THEN MAINTAIN DRY WEATHER UNTIL PASSAGE OF ANOTHER WEAK CDFNT ON THU. LTD MSTR IS PROGGED WITH THAT FNT...SO ONLY SLGT CHC POPS WERE INCLUDED ATTM. UNDR ERN CONUS TROFG ALOFT...SUB AVG TEMPS ARE EXPD INTO SATURDAY. && .AVIATION /19Z SATURDAY THROUGH THURSDAY/... GENERAL VFR EXPECTED IS FORECAST TODAY ALTHOUGH SOME SHWRS AND TSTMS MAY MAR UPR OH VALLEY WEA LTR THIS AFTN AND THIS EVE. THE BTR CHC OF THIS OCCURRENCE LKS TO BE OVR AREAS E OF PIT AS PER POSITIONING OF A SLOW-MOVG MID LVL TROF. TAFS HAVE THUS BEEN AMENDED TO INCLUDED TSTM MENTION AT ONLY AT MGW FOR NOW. OTHERWISE...A MORE SIGNIFICANT SHRTWV IS MDL-INDICATED FOR A SUNDAY PASSAGE. GIVEN MSTR SUPPLY AND INCRSG ASCENT...HAVE FORECAST DEGRADED CIGS/MVFR CONDITIONS FOR THE PREDAWN WITH IFR AT FKL AND DUJ. MORE WIDESPREAD SHWRS AND CONTD RESTRICTIONS ARE ANTICIPATED FOR SUNDAY. .OUTLOOK.../SUNDAY THROUGH THURSDAY/... A DECISIVE CDFNT PASSAGE IS STILL SLATED FOR MONDAY. RESTRICTIONS MAY THUS BE EXPECTED UNTIL HIGH PRES BUILDS FOR TUESDAY THROUGH THURSDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE PITTSBURGH PA 1257 AM EDT SAT AUG 31 2013 MDZ001-OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023- 029-031-073>076-WVZ001>004-012-021>023-041-010500- 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- 1257 AM EDT SAT AUG 31 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...TONIGHT. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PITTSBURGH PA
526 PM EDT SAT AUG 31 2013
PAZ015-016-312230-
CLARION PA-JEFFERSON PA-
526 PM EDT SAT AUG 31 2013
...STRONG THUNDERSTORMS WILL AFFECT JEFFERSON AND SOUTHERN CLARION
COUNTIES...
AT 520 PM EDT...STRONG THUNDERSTORMS WERE ALONG A LINE FROM CLEAR
CREEK STATE PARK TO 2 MILES NORTHEAST OF SLIGO...MOVING SOUTHEAST AT
10 MPH.
WIND GUSTS TO 40 MPH ARE POSSIBLE WITH THESE STORMS. IN
ADDITION...WITH THE SLOW MOVEMENT OF THESE STORMS...HEAVY RAIN
COULD POND WATER ON ROADS AND QUICKLY FILL SMALL STREAMS.
LOCATIONS IMPACTED INCLUDE...
SLIGO... CLEAR CREEK STATE PARK...
CLARION... RIMERSBURG... LIMESTONE...
SUMMERVILLE... BROOKVILLE... NEW BETHLEHEM...
BROCKWAY... REYNOLDSVILLE... PUNXSUTAWNEY...
DORA...
PLEASE REPORT SIGNIFICANT WEATHER BY CALLING...412-262-1988...POSTING
TO THE NWS PITTSBURGH FACEBOOK PAGE...OR USING TWITTER
@NWSPITTSBURGH.
LAT...LON 4120 7871 4119 7877 4112 7880 4090 7880
4091 7921 4105 7922 4101 7928 4100 7936
4098 7937 4101 7941 4099 7943 4108 7967
4134 7917 4133 7911 4136 7908 4138 7898
4127 7874 4124 7874 4123 7870
34The Pittsburgh radar (KPBZ), 103 km away, was scanning. The volume nearest the first event began at 22:13 UTC.
1 thunderstorm wind, 1 flood. Local standard time, as filed.
State official reported multiple trees down.
State official reported that Route 28 was shut down from Brookville Boro to Summerville due to flooding.
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, August 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: 475435, 475436.