Alert archive / Pennsylvania / Flash Flood Warnings in 2021
Flash Flood Warning 30, NWS Pittsburgh, PA
NWS Pittsburgh, PA issued this flash flood warning at Aug 25, 2021, 5:17 PM EDT for Allegheny County, Butler County, Pennsylvania. It was in force for 88 min. 3 reports came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Aug 25, 2021, 5:17 PM EDT (21:17 UTC)
- Expired
- Aug 25, 2021, 6:45 PM EDT
- In force
- 88 min
- Issued by
- NWS Pittsburgh, PA
- Area
- Storm-based polygon
- Flood severity
- None
Counties Allegheny County, PA, Butler County, PA
The radar
The Pittsburgh radar (KPBZ), 18 km from the middle of the area, began a volume at 21:18 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 25, 5:30 PM EDT | FLASH FLOOD | Lovi, PA | JACKSON BOULEVARD FLOODED |
| Aug 25, 5:35 PM EDT | FLASH FLOOD | 1 S Fernway, PA | FLOODING ON JANE STREET |
| Aug 25, 5:35 PM EDT | FLASH FLOOD | 1 Wsw Mars, PA | FLOODING ON A FEW ROADS IN ADAMS TOWNSHIP |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Pittsburgh, PA (KPIT), launched 12:00Z, 9.3 hours before the alert went out and 30 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
- 323 J/kg
- Mixed-layer CIN
- -55 J/kg
- Mixed-layer LCL
- 1166 m above ground
- 0-6 km bulk shear
- 5 kt
- 0-1 km storm-relative helicity
- -18 m²/s²
- 0-3 km storm-relative helicity
- -18 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
183
WGUS51 KPBZ 252117
FFWPBZ
PAC003-019-252245-
/O.NEW.KPBZ.FF.W.0030.210825T2117Z-210825T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Pittsburgh PA
517 PM EDT Wed Aug 25 2021
The National Weather Service in Pittsburgh has issued a
* Flash Flood Warning for...
North Central Allegheny County in southwestern Pennsylvania...
Southwestern Butler County in west central Pennsylvania...
* Until 645 PM EDT.
* At 517 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 1.5 and 2.5 inches of
rain have fallen. Additional rainfall amounts of 1 to 2 inches are
possible in the warned area. 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...
McCandless Township, Cranberry, Franklin Park, Hampton Township,
Economy, Wexford, Zelienople, Seven Fields, Gibsonia, Oak Hills,
Evans City, Mars, Bell Acres, Nixon, Bradfordwoods, Harmony,
Valencia, Connoquenessing, Callery and Pine Township.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be aware of your surroundings and do not drive on flooded roads.
&&
LAT...LON 4082 8016 4082 7991 4060 7990 4059 8020
4060 8019 4061 8018 4061 8017 4061 8015
FLASH FLOOD...RADAR INDICATED
$$3 follow-up statements
899
WGUS71 KPBZ 252130
FFSPBZ
Flash Flood Statement
National Weather Service Pittsburgh PA
530 PM EDT Wed Aug 25 2021
PAC003-019-252245-
/O.CON.KPBZ.FF.W.0030.000000T0000Z-210825T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Allegheny PA-Butler PA-
530 PM EDT Wed Aug 25 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 PM EDT THIS
EVENING FOR NORTH CENTRAL ALLEGHENY AND SOUTHWESTERN BUTLER
COUNTIES...
At 530 PM EDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Between 1.5 and 3 inches of rain have
fallen. Additional rainfall amounts of 1 to 2 inches are possible in
the warned area. Flash flooding is ongoing or expected to begin
shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar.
IMPACT...Flash flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other poor
drainage and low-lying areas.
Some locations that will experience flash flooding include...
McCandless Township, Cranberry, Franklin Park, Hampton Township,
Economy, Wexford, Zelienople, Seven Fields, Gibsonia, Oak Hills,
Evans City, Mars, Bell Acres, Nixon, Bradfordwoods, Harmony,
Valencia, Connoquenessing, Callery and Pine Township.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be aware of your surroundings and do not drive on flooded roads.
&&
LAT...LON 4082 8016 4082 7991 4060 7990 4059 8020
4060 8019 4061 8018 4061 8017 4061 8015
FLASH FLOOD...RADAR INDICATED
$$874
WGUS71 KPBZ 252158
FFSPBZ
Flash Flood Statement
National Weather Service Pittsburgh PA
558 PM EDT Wed Aug 25 2021
PAC003-019-252245-
/O.CON.KPBZ.FF.W.0030.000000T0000Z-210825T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Allegheny PA-Butler PA-
558 PM EDT Wed Aug 25 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 PM EDT THIS
EVENING FOR NORTH CENTRAL ALLEGHENY AND SOUTHWESTERN BUTLER
COUNTIES...
At 558 PM EDT, local law enforcement reported thunderstorms
producing heavy rain across the warned area. Between 2 and 3 inches
of rain have fallen. Additional rainfall amounts up to 1 inch are
possible in the warned area. Flash flooding is ongoing or expected
to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Law enforcement reported.
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...
McCandless Township, Cranberry, Franklin Park, Hampton Township,
Economy, Wexford, Zelienople, Seven Fields, Gibsonia, Oak Hills,
Evans City, Mars, Bell Acres, Nixon, Bradfordwoods, Harmony,
Valencia, Connoquenessing, Callery and Pine Township.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be aware of your surroundings and do not drive on flooded roads.
&&
LAT...LON 4082 8016 4082 7991 4060 7990 4059 8020
4060 8019 4061 8018 4061 8017 4061 8015
FLASH FLOOD...OBSERVED
$$319
WGUS71 KPBZ 252242
FFSPBZ
Flash Flood Statement
National Weather Service Pittsburgh PA
642 PM EDT Wed Aug 25 2021
PAC003-019-252252-
/O.EXP.KPBZ.FF.W.0030.000000T0000Z-210825T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Allegheny PA-Butler PA-
642 PM EDT Wed Aug 25 2021
...FLASH FLOOD WARNING WILL EXPIRE AT 645 PM EDT THIS EVENING FOR
NORTH CENTRAL ALLEGHENY AND SOUTHWESTERN BUTLER COUNTIES...
The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.
LAT...LON 4082 8016 4082 7991 4060 7990 4059 8020
4060 8019 4061 8018 4061 8017 4061 8015
$$The office that day
Everything else NWS Pittsburgh, PA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 25, 3:12 PM EDT | Special Weather Statement | PBZ | Mercer | 33 min |
| Aug 25, 3:34 PM EDT | Areal Flood Advisory | PBZ | Mercer | 116 min |
| Aug 25, 3:43 PM EDT | Special Weather Statement | PBZ | Allegheny | 32 min |
| Aug 25, 4:12 PM EDT | Special Weather Statement | PBZ | Butler | 18 min |
| Aug 25, 4:46 PM EDT | Special Weather Statement | PBZ | Beaver | 14 min |
| Aug 25, 4:50 PM EDT | Areal Flood Advisory | PBZ | Allegheny, Butler | 27 min |
| Aug 25, 5:20 PM EDT | Special Weather Statement | PBZ | Butler | 10 min |
| Aug 25, 5:21 PM EDT | Flash Flood Warning | PBZ | Beaver | 29 min |
| Aug 25, 5:25 PM EDT | Areal Flood Advisory | PBZ | Butler | 27 min |
| Aug 25, 5:29 PM EDT | Areal Flood Advisory | PBZ | Allegheny, Washington | 37 min |
| Aug 25, 5:35 PM EDT | Special Weather Statement | PBZ | Butler | 25 min |
| Aug 25, 5:52 PM EDT | Flash Flood Warning | PBZ | Butler | 74 min |
| Aug 25, 5:56 PM EDT | Flash Flood Warning | PBZ | Butler | 89 min |
| Aug 25, 6:05 PM EDT | Flash Flood Warning | PBZ | Allegheny, Washington | 46 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.