Alert archive / Pennsylvania / Flash Flood Warnings in 2021
Flash Flood Warning 38, NWS Pittsburgh, PA
NWS Pittsburgh, PA issued this flash flood warning at Aug 31, 2021, 1:22 PM EDT for Allegheny County, Westmoreland County, Pennsylvania. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Aug 31, 2021, 1:22 PM EDT (17:22 UTC)
- Expired
- Aug 31, 2021, 3:49 PM EDT
- In force
- 2 hr
- Issued by
- NWS Pittsburgh, PA
- Area
- Storm-based polygon
- Flood severity
- None
Counties Allegheny County, PA, Westmoreland County, PA
The radar
The Pittsburgh radar (KPBZ), 29 km from the middle of the area, began a volume at 17:23 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, 5.4 hours before the alert went out and 15 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.
- Mixed-layer CAPE
- 15 J/kg
- Mixed-layer CIN
- -48 J/kg
- Mixed-layer LCL
- 1074 m above ground
- 0-6 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 2 m²/s²
- 0-3 km storm-relative helicity
- 84 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted.
950
WGUS51 KPBZ 311722
FFWPBZ
PAC003-129-312030-
/O.NEW.KPBZ.FF.W.0038.210831T1722Z-210831T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Pittsburgh PA
122 PM EDT Tue Aug 31 2021
The National Weather Service in Pittsburgh has issued a
* Flash Flood Warning for...
Central Allegheny County in southwestern Pennsylvania...
West Central Westmoreland County in southwestern Pennsylvania...
* Until 430 PM EDT.
* At 122 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 1 and 2 inches of rain
have fallen. Flash flooding is ongoing or expected to begin
shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar.
IMPACT...Flash flooding of small creeks and streams, urban
areas, highways, streets and underpasses as well as
other poor drainage and low-lying areas.
* Some locations that will experience flash flooding include...
Pittsburgh, Penn Hills, Mount Lebanon, Bethel Park, Ross Township,
Monroeville, McKeesport, Shaler Township, Plum, West Mifflin,
North Side Pittsburgh, Baldwin, Upper St. Clair, Murrysville,
Scott Township, Wilkinsburg, Whitehall, South Park Township,
Robinson Township and Munhall.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 4034 7978 4032 8010 4038 8023 4046 8025
4052 7998 4049 7978 4044 7970 4037 7970
FLASH FLOOD...RADAR INDICATED
$$
Brown1 follow-up statement
035
WGUS71 KPBZ 311949
FFSPBZ
Flash Flood Statement
National Weather Service Pittsburgh PA
349 PM EDT Tue Aug 31 2021
PAC003-129-311959-
/O.CAN.KPBZ.FF.W.0038.000000T0000Z-210831T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Allegheny PA-Westmoreland PA-
349 PM EDT Tue Aug 31 2021
...FLASH FLOOD WARNING IS CANCELLED FOR CENTRAL ALLEGHENY AND WEST
CENTRAL WESTMORELAND COUNTIES...
Flood waters have receded. The heavy rain has ended. Flooding is no
longer expected to pose a threat. Please continue to heed remaining
road closures.
LAT...LON 4034 7978 4032 8010 4038 8023 4046 8025
4052 7998 4049 7978 4044 7970 4037 7970
$$
JLThe office that day
Everything else NWS Pittsburgh, PA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 31, 12:25 PM EDT | Areal Flood Advisory | PBZ | Westmoreland | 2 hr |
| Aug 31, 12:43 PM EDT | River Flood Watch | PBZ | Fayette, Washington | 56 hr |
| Aug 31, 12:43 PM EDT | River Flood Watch | PBZ | Allegheny, Westmoreland | 62 hr |
| Aug 31, 1:14 PM EDT | Flash Flood Warning | PBZ | Westmoreland | 76 min |
| Aug 31, 2:41 PM EDT | Areal Flood Advisory | PBZ | Allegheny, Armstrong, Beaver, Butler, Westmoreland | 2 hr |
| Aug 31, 3:55 PM EDT | Areal Flood Advisory | PBZ | Allegheny, Washington, Westmoreland | 2 hr |
| Aug 31, 5:05 PM EDT | Areal Flood Advisory | PBZ | Washington | 115 min |
| Aug 31, 5:52 PM EDT | Flash Flood Warning | PBZ | Allegheny, Washington, Westmoreland | 113 min |
Nearby
Flash Flood Warnings in Pennsylvania, 2021Every flash flood warning in 2021
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.