Alert archive / Pennsylvania / Flash Flood Warnings in 2023

Flash Flood Warning 10, NWS Pittsburgh, PA

July 9, 2023Allegheny County, Pennsylvania

NWS Pittsburgh, PA issued this flash flood warning at Jul 9, 2023, 4:30 PM EDT for Allegheny County, Pennsylvania. It was in force for 90 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jul 9, 2023, 4:30 PM EDT (20:30 UTC)
Expired: Jul 9, 2023, 6:00 PM EDT
In force: 90 min
Issued by: NWS Pittsburgh, PA
Area: Storm-based polygon
Flood severity: None

County Allegheny County, PA

The radar

The Pittsburgh radar (KPBZ), 21 km from the middle of the area, began a volume at 20:32 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 8.5 hours before the alert went out and 278 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 952 J/kg
Mixed-layer CIN: -58 J/kg
Mixed-layer LCL: 686 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 12 m²/s²
0-3 km storm-relative helicity: 37 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood warning went out, 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 this flash flood warning went out at Jul 9, 1:47 PM EDT, 2 hours 43 minutes earlier.

Area forecast discussion, Jul 9, 1:47 PM EDT, 2 hours 43 minutes before

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Hazardous weather outlook, Jul 9, 1:55 PM EDT, 2 hours 35 minutes before

Hazardous Weather Outlook
National Weather Service Pittsburgh PA
155 PM EDT Sun Jul 9 2023

OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>022-029-
031-073>078-WVZ001>004-012-021-509>514-101800-
Tuscarawas-Carroll-Columbiana-Coshocton-Harrison-Jefferson OH-
Muskingum-Guernsey-Belmont-Noble-Monroe-Mercer-Venango-Forest-
Lawrence-Butler-Clarion-Jefferson PA-Beaver-Allegheny-Armstrong-
Washington-Greene-Westmoreland-Higher Elevations of Westmoreland-
Fayette-Higher Elevations of Fayette-Indiana-
Higher Elevations of Indiana-Hancock-Brooke-Ohio-Marshall-Wetzel-
Marion-Monongalia-
Ridges of Eastern Monongalia and Northwestern Preston-Preston-
Eastern Preston-Western Tucker-Eastern Tucker-
155 PM EDT Sun Jul 9 2023

This Hazardous Weather Outlook is for east central Ohio, western
Pennsylvania, and northern 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.

The office that day

Everything else NWS Pittsburgh, PA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 9, 6:04 PM EDT	Flash Flood Warning	PBZ	Lawrence	6 hr
Jul 9, 7:13 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Beaver	32 min

Nearby

Flash Flood Warnings in Pennsylvania, 2023 Every flash flood warning in 2023

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.