Alert archive / Pennsylvania / Flash Flood Warnings in 2026

Flash Flood Warning 91, NWS Pittsburgh, PA

August 10, 2026Allegheny County, Washington County, Westmoreland County, Pennsylvania

NWS Pittsburgh, PA issued this flash flood warning at Aug 10, 2026, 11:58 AM EDT for Allegheny County, Washington County, Westmoreland County, Pennsylvania. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Aug 10, 2026, 11:58 AM EDT (15:58 UTC)
Expired: Aug 10, 2026, 3:00 PM EDT
In force: 3 hr
Issued by: NWS Pittsburgh, PA
Area: Storm-based polygon
Flood severity: None

Counties Allegheny County, PA, Washington County, PA, Westmoreland County, PA

The radar

The Pittsburgh radar (KPBZ), 36 km from the middle of the area, began a volume at 16:01 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

Pittsburgh, PA (KPIT), launched 12:00Z, 4.0 hours before the alert went out and 20 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: 1604 J/kg
Mixed-layer CIN: -34 J/kg
Mixed-layer LCL: 812 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 149 m²/s²
0-3 km storm-relative helicity: 134 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 4.2

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 Aug 10, 9:36 AM EDT, 2 hours 22 minutes earlier.

Area forecast discussion, Aug 10, 9:36 AM EDT, 2 hours 22 minutes before

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Hazardous weather outlook, Aug 10, 2:44 AM EDT, 9 hours 14 minutes before

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In the hours before

Special weather statement, Aug 10, 9:05 AM EDT, 2 hours 53 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 10, 10:07 AM EDT	Flood Watch	PBZ	Allegheny, Beaver, Fayette, Greene, Washington, Westmoreland	41 hr
Aug 10, 10:56 AM EDT	Severe Thunderstorm Warning	PBZ	Washington	55 min
Aug 10, 12:06 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Washington, Westmoreland	54 min
Aug 10, 12:42 PM EDT	Flash Flood Warning	PBZ	Allegheny, Westmoreland	3 hr
Aug 10, 12:48 PM EDT	Severe Thunderstorm Warning	PBZ	Fayette, Greene	57 min
Aug 10, 1:03 PM EDT	Severe Thunderstorm Warning	PBZ	Fayette, Westmoreland	21 min
Aug 10, 4:22 PM EDT	Severe Thunderstorm Warning	PBZ	Greene, Washington	41 min
Aug 10, 9:48 AM EDT	Severe Thunderstorm Warning	PBZ	Carroll, Columbiana	57 min
Aug 10, 9:51 AM EDT	Severe Thunderstorm Warning	PBZ	Carroll, Columbiana, Coshocton, Harrison, Tuscarawas	54 min
Aug 10, 9:59 AM EDT	Severe Thunderstorm Warning	PBZ	Coshocton, Guernsey, Harrison, Muskingum, Noble, Tuscarawas	61 min
Aug 10, 11:28 AM EDT	Severe Thunderstorm Warning	PBZ	Guernsey, Muskingum, Noble	51 min
Aug 10, 11:32 AM EDT	Flash Flood Warning	PBZ	Harrison, Jefferson	3 hr
Aug 10, 4:38 PM EDT	Severe Thunderstorm Warning	PBZ	Belmont, Guernsey, Monroe, Noble	25 min
Aug 10, 1:28 PM EDT	Severe Thunderstorm Warning	PBZ	Preston	21 min

Nearby

Flash Flood Warnings in Pennsylvania, 2026 Every flash flood warning in 2026

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.