Non-severe thunderstorms tracked across Allegheny County during the evening of September 7th. 5 inches north of Pittsburgh created some localized flash flooding issues.
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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.
Non-severe thunderstorms tracked across Allegheny County during the evening of September 7th. Localized 3-hour rainfall totals of 1.5 to 2.5 inches north of Pittsburgh created some localized flash flooding issues.
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 7, 5:14 PM EST, 1 hour 1 minute earlier.
Area Forecast Discussion National Weather Service Pittsburgh PA 614 PM EDT Thu Sep 7 2023 .SYNOPSIS... A slow moving cold front will eventually move through the region this evening. Behind this front, cooler temperatures and unsettled weather are expected to linger into the weekend. && .NEAR TERM /THROUGH FRIDAY/... A broken line of showers and storms will continue to progress eastward with a cold front this evening. The main risk from this activity will be the potential for isolated heavy rainfall totals/localized flooding. Cell motion is parallel to the boundary from SSW to NNE at present, and with the front's slow eastward progress, cannot rule isolated 1 to 2 inch rainfall totals in an hour or two. The front will cross into central Pennsylvania this evening, taking the bulk of the showers/storms with it, and a relative lull in activity is expected overnight. A secondary front will approach from the west this evening, and then likely stall near or in the ridges towards morning. An isolated shower or two cannot be ruled out. Low clouds and patchy fog/mist are likely in lingering low-level moisture. Low temperatures will remain some 5 to 8 degrees above normal. && .SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY/... The secondary boundary will remain stalled or move eastward only very slightly eastward into Friday night, as ridging just off of the Eastern Seaboards slows progress. Additional shower development is expected Friday, especially near the boundary, with enough lingering moisture and instability to support cellular activity. Thunderstorms will be possible, but again, most of the significant activity will lie off to the east in higher instability. The front will finally get a better eastward push Friday night into Saturday as a shortwave starts to dig into the Ohio Valley. Additional shower activity can be expected, again more concentrated across the eastern counties, closer to the front. Temperatures Friday and Saturday will be close to seasonal averages. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... This period will be mainly dominated by eastern CONUS troughing, leading to below-normal temperatures for the majority of the extended period. Coverage of showers/several thunderstorms will be quite high during the afternoon/evening period of Sunday as a shortwave settles in to the Middle Ohio Valley, with vorticity advection and upper divergence promoting lift. This main shortwave crosses the Appalachians Sunday night, leading to decreasing rain chances. A relative lull is forecast for Monday into Monday night, as temporary surface high pressure and mid-level zonal flow promote mostly dry conditions and temperatures a bit closer to climatology. The large-scale trough will then be reinforced by another upper low/significant shortwave trough dropping into Michigan during the midweek period. There is disagreement on the details in the models, but a return to below-normal temperatures and scattered showers seems possible for the Tuesday through Thursday period. && .AVIATION /22Z THURSDAY THROUGH TUESDAY/... Patchy MVFR to low VFR cu/stratocu cigs will continue through mid afternoon with low convective temperatures in place. A broken line of showers and thunderstorms in advance of a cold front will continue to move across the region through this evening. Included a tempo group in the TAFs for the passage of this line. Not confident thunder will occur at all sites with limited instability, though at least some showers are expected. VFR is expected this evening as the convection diminishes, and the front moves east before stalling. Low level moisture in place should result in IFR stratus/fog develop overnight through Friday morning. A gradual improvement to MVFR is expected Friday morning as limited mixing lifts cig heights. Further improvement to VFR cigs is expected later in the afternoon under this continued mixing. .OUTLOOK... Patchy IFR in fog/stratus is possible Friday night/Saturday morning with low level moisture in place. Periodic restrictions in showers/thunderstorms are possible under an upper trough Saturday and Sunday. Some improvement is possible Monday under weak high pressure. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && SYNOPSIS...CL/88 NEAR TERM... SHORT TERM... LONG TERM...CL AVIATION...WM
Hazardous Weather Outlook National Weather Service Pittsburgh PA 336 AM EDT Thu Sep 7 2023 OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>015-020>022-029- 031-073-075-WVZ001>004-012-080745- Tuscarawas-Carroll-Columbiana-Coshocton-Harrison-Jefferson OH- Muskingum-Guernsey-Belmont-Noble-Monroe-Mercer-Venango-Forest- Lawrence-Butler-Clarion-Beaver-Allegheny-Armstrong-Washington-Greene- Westmoreland-Fayette-Hancock-Brooke-Ohio-Marshall-Wetzel- 336 AM EDT Thu Sep 7 2023 This Hazardous Weather Outlook is for east central Ohio, western Pennsylvania, and northern 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. PAZ016-074-076>078-WVZ021-509>514-080745- Jefferson PA-Higher Elevations of Westmoreland- Higher Elevations of Fayette-Indiana-Higher Elevations of Indiana- Marion-Monongalia- Ridges of Eastern Monongalia and Northwestern Preston-Preston- Eastern Preston-Western Tucker-Eastern Tucker- 336 AM EDT Thu Sep 7 2023 This Hazardous Weather Outlook is for western Pennsylvania and northern West Virginia. .DAY ONE...Today and tonight. Isolated storms could reach severe levels this afternoon and evening. The main threat will be damaging wind gusts and hail. .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.
The Pittsburgh radar (KPBZ), 16 km away, was scanning. The volume nearest the first event began at 23:15 UTC.
2 flash flood. Local standard time, as filed.
Flooding was reported on Pine Creek Road near Old Perry Highway. Another report indicates that several vehicles were stranded in the area.
Pine Creek was out of its banks near Huntington Court.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2023Every state in 2023This day in weather historyWarnings in Pennsylvania, September 2023
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: 1133970, 1133971.