Scattered thunderstorms developed across the region as a cold front moved south. Isolated flash flooding occurred over Allegheny county.
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.
Scattered thunderstorms developed across the region as a cold front moved south. Isolated flash flooding occurred over Allegheny county.
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 Jul 21, 3:15 PM EST, 2 hours 40 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 415 PM EDT SUN JUL 21 2013 .SYNOPSIS... A WEAK COLD FRONT WILL DRIFT SOUTH ACROSS THE REGION TONIGHT. A SERIES OF DISTURBANCES WILL CROSS THE AREA THIS WEEK CAUSING UNSETTLED WEATHER. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... A WK SFC BNDRY ACRS W CNTRL PA INTO OH WL DRIFT SLOWLY SWD TNGT. INSTBY CHART AND RECENT MESO ANALYSIS INDICATE ONLY WK INSTBY...SO THE ISOLD SHWRS/TSTMS INVOF THIS BNDRY SHOULD DMNSH ARND SUNSET. EXP SHWR CHCS TO INCR LT TNGT MAINLY ACRS ERN OHIO AS AN UPPER LEVEL TROUGH MOVES EAST. TEMPERATURES A GENERAL BLEND OF MODEL MOS. && .SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/... IT WILL BE INTERESTING TO SEE WHERE THE COLD FRONT IS LOCATED AT THE START OF THE PERIOD. NOT A GOOD WIND FIELD TO PUSH THE FRONT SOUTH...SO IT CONTINUES TO OOZE SOUTH THROUGH THE DAY MONDAY. WOULD NOT BE SURPRISED TO SEE THE BAROCLINIC ZONE AROUND I-70 CORRIDOR AT DAWN MONDAY THEN JUST WASH OUT AS S/W TROUGH APPROACHES FROM THE WEST. EARLIER MODEL RUNS ILLUSTRATED THIS BOUNDARY WOULD RETURN AS A WARM FRONT IN NAME ONLY...HOWEVER WITH SLOW SOUTHWARD PROGRESSION...THAT SOLUTION IS UNLIKELY. MID LEVEL WAVES CROSSES MONDAY AFTERNOON AND GIVEN AMPLE MOISTURE ILLUSTRATED BY MODEL SOUNDINGS INCREASES POPS FARTHER INTO THE LKLY/LOW CAT RANGE S OF THE M/D LINE. BRIEF BREAK IN THE WEATHER MONDAY NIGHT BEFORE YET ANOTHER WAVE TRAVERSES THE WESTERN GREAT LAKES TUESDAY. HIGHEST PWATS REMAIN OVER NRN WV SO ANY CHANCE OF LOCALIZED FLOODING WOULD OCCUR THERE. COLD FRONT PASSES TUES NGT INTO WED. GIVEN TIMING OF FRONT AND LITTLE SOLAR HEATING DURING THE DAY...ANY STORM SHOULD REMAIN BELOW SEVERE LIMITS. H5 TROF AXIS WILL BRING THE POTENTIAL FOR POST FRONTAL SHOWERS WED. TEMPS WERE DERIVED FROM BIAS CORRECTED MOSGUIDE GRIDS. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... BROAD UPPER LEVEL TROUGH WILL REMAIN OVER THE EASTERN CONUS THROUGH THE EXTENDED PERIOD. HOWEVER...AFTER A MORE PROMINENT FRONTAL BOUNDARY CROSSES BY THURSDAY...THERE COULD BE A BRIEF PERIOD WHERE SURFACE HIGH PRESSURE TAKES CONTROL...AS SUGGESTED BY THE ECMWF AND GFS. THE MODEL SOLUTIONS THEN DIVERGE ON THE TIMING OF SUBSEQUENT SHORTWAVES AFTER FRIDAY...SO CHANCE POPS WERE KEPT IN THE FORECAST FOR THE WEEKEND. WITH THE TROUGH IN PLACE TEMPERATURES WILL BE MUCH CLOSER TO SEASONAL AVERAGES THROUGH THE PERIOD. && .AVIATION /20Z SUNDAY THROUGH FRIDAY/... CONDITIONS HAVE IMPROVED TO GENERAL VFR THIS AFTERNOON AND WILL CONTINUE INTO THE EVENING. ISOLATED THUNDERSTORM COVERAGE NOT ENOUGH PROBABILITY TO INCLUDE IN ANY PARTICULAR TAF AS BOUNDARY ALONG I-80 SINKS SOUTH. VERY WEAK WIND FLOW AND WINDS WILL BE VARIABLE UNDER 5 KTS THROUGH THE TAF PERIOD. BY 06-07Z OVERNIGHT WIDESPREAD IFR FOG EXPECTED AT MOST LOCATIONS AND TO CONTINUE UNTIL 13-14Z. AS AN UPPER LEVEL TROUGH APPROACHES MONDAY MORNING SHOWERS WILL INCREASE ACROSS REGION AS THE DAY PROGRESSES. OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/... WHILE VFR IS EXPECTED MUCH OF THE TIME A SERIES OF SHORTWAVES ALOFT WILL BRING OCCASIONAL RESTRICTIONS INTO THURSDAY. WEAK HIGH PRESSURE WILL GIVE WIDESPREAD IFR FRIDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE PITTSBURGH PA 416 PM EDT SUN JUL 21 2013 MDZ001-OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023- 029-031-073>076-WVZ001>004-012-021>023-041-222015- 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- 416 PM EDT SUN JUL 21 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...THIS AFTERNOON AND TONIGHT. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. 07
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PITTSBURGH PA
620 PM EDT SUN JUL 21 2013
PAZ021-073-212300-
ALLEGHENY PA-WESTMORELAND PA-
620 PM EDT SUN JUL 21 2013
...A STRONG THUNDERSTORM WILL AFFECT SOUTHEASTERN ALLEGHENY AND WEST
CENTRAL WESTMORELAND COUNTIES...
AT 615 PM EDT...A CLUSTER OF SLOW MOVING THUNDERSTORMS WERE CENTERED
JUST SOUTH OF TURTLE CREEK MOVING SOUTH AT 10 MPH.
HEAVY RAIN WILL POND WATER ON ROADS AND QUICKLY FILL SMALL STREAMS.
LOCATIONS IMPACTED INCLUDE...
WEST MIFFLIN... TURTLE CREEK... MONROEVILLE...
MCKEESPORT... ELIZABETH BORO... MONESSEN...
MURRYSVILLE... WEST NEWTON... IRWIN...
EXCESSIVE RUNOFF WILL ELEVATE SMALL STREAMS. PONDING OF WATER CAN BE
EXPECTED IN POOR DRAINAGE AREAS...LOW LYING SPOTS...AND UNDERPASSES.
THESE STORMS ARE AFFECTING ROUTE 30 AND ROUTE 48.
PLEASE REPORT SIGNIFICANT WEATHER BY CALLING...412-262-1988...POSTING
TO THE NWS PITTSBURGH FACEBOOK PAGE...OR USING TWITTER
@NWSPITTSBURGH.
LAT...LON 4013 7974 4013 7988 4016 7990 4016 7986
4019 7985 4020 7991 4021 7995 4023 7997
4025 7992 4028 8002 4048 7982 4040 7960The Pittsburgh radar (KPBZ), 41 km away, was scanning. The volume nearest the first event began at 22:53 UTC.
3 flash flood. Local standard time, as filed.
The public reported flash flooding as Turtle Creek came out of its banks and flooded Route 48.
The 911 call center reported flash flooding with vehicles with passengers swamped on Route 837.
The 911 Call Center found an unoccupied car in flash flooding on 5th Avenue and Cliff Street.
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, July 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: 462897, 462898, 462899.