Alert archive / Pennsylvania / Flash Flood Warnings in 2020
Flash Flood Warning 21, NWS Pittsburgh, PA
NWS Pittsburgh, PA issued this flash flood warning at Aug 22, 2020, 8:25 PM EDT for Allegheny County, Pennsylvania. It was in force for 68 min. 1 report 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 22, 2020, 8:25 PM EDT (00:25 UTC)
- Expired
- Aug 22, 2020, 9:33 PM EDT
- In force
- 68 min
- Issued by
- NWS Pittsburgh, PA
- Area
- Storm-based polygon
- Flood severity
- None
County Allegheny County, PA
The radar
The Pittsburgh radar (KPBZ), 23 km from the middle of the area, began a volume at 00:28 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 22, 8:30 PM EDT | FLASH FLOOD | Whitehall, PA | A CREEK IS OVERFLOWING ONTO THE ROAD SOUTHERN ALLEGHENY COUNTY. |
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 00:00Z, 0.4 hours before the alert went out and 9 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
- 151 J/kg
- Mixed-layer CIN
- -31 J/kg
- Mixed-layer LCL
- 2087 m above ground
- 0-6 km bulk shear
- 6 kt
- 0-1 km storm-relative helicity
- -15 m²/s²
- 0-3 km storm-relative helicity
- 4 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
834
WGUS51 KPBZ 230025
FFWPBZ
PAC003-230200-
/O.NEW.KPBZ.FF.W.0021.200823T0025Z-200823T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Pittsburgh PA
825 PM EDT Sat Aug 22 2020
The National Weather Service in Pittsburgh has issued a
* Flash Flood Warning for...
Central Allegheny County in southwestern Pennsylvania...
* Until 1000 PM EDT.
* At 825 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 1.5 and 2 inches of
rain have fallen. Flash flooding is ongoing or expected to begin
shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Doppler radar.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other
drainage and low lying areas.
* Some locations that will experience flash flooding include...
Pittsburgh, Mount Lebanon, Bethel Park, Ross Township, McKeesport,
Shaler Township, West Mifflin, North Side Pittsburgh, Baldwin,
Scott Township, Wilkinsburg, Whitehall, South Park Township,
Munhall, Jefferson Hills, Brentwood, Swissvale, Dormont, O'hara
Township and Castle Shannon.
Additional rainfall amounts of 0.5 to 1 inch are possible in the
warned area.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
&&
LAT...LON 4043 8006 4029 8002 4028 7985 4054 7992
4047 8007
FLASH FLOOD...RADAR INDICATED
$$2 follow-up statements
039
WGUS71 KPBZ 230039
FFSPBZ
Flash Flood Statement
National Weather Service Pittsburgh PA
839 PM EDT Sat Aug 22 2020
PAC003-230200-
/O.CON.KPBZ.FF.W.0021.000000T0000Z-200823T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Allegheny PA-
839 PM EDT Sat Aug 22 2020
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 10 PM EDT THIS
EVENING FOR CENTRAL ALLEGHENY COUNTY...
At 839 PM EDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Between 1 and 2 inches of rain have
fallen. Flash flooding is ongoing or expected to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Doppler radar.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other
drainage and low lying areas.
Some locations that will experience flash flooding include...
Pittsburgh, Mount Lebanon, Bethel Park, Ross Township, McKeesport,
Shaler Township, West Mifflin, North Side Pittsburgh, Baldwin,
Scott Township, Wilkinsburg, Whitehall, South Park Township,
Munhall, Jefferson Hills, Brentwood, Swissvale, Dormont, O'hara
Township and Castle Shannon.
Additional rainfall amounts up to 0.5 inches are possible in the
warned area.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
&&
LAT...LON 4043 8006 4029 8002 4028 7985 4054 7992
4047 8007
FLASH FLOOD...RADAR INDICATED
$$477
WGUS71 KPBZ 230133
FFSPBZ
Flash Flood Statement
National Weather Service Pittsburgh PA
933 PM EDT Sat Aug 22 2020
PAC003-230143-
/O.CAN.KPBZ.FF.W.0021.000000T0000Z-200823T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Allegheny PA-
933 PM EDT Sat Aug 22 2020
...FLASH FLOOD WARNING IS CANCELLED FOR CENTRAL ALLEGHENY COUNTY...
The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.
LAT...LON 4043 8006 4029 8002 4028 7985 4054 7992
4047 8007
$$The office that day
Everything else NWS Pittsburgh, PA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 22, 8:03 PM EDT | Areal Flood Advisory | PBZ | Allegheny | 22 min |
| Aug 22, 8:10 PM EDT | Severe Thunderstorm Warning | PBZ | Allegheny | 35 min |
| Aug 22, 8:39 PM EDT | Special Weather Statement | PBZ | Allegheny | 36 min |
| Aug 22, 9:19 PM EDT | Areal Flood Advisory | PBZ | Allegheny | 56 min |
| Aug 22, 11:33 PM EDT | Areal Flood Advisory | PBZ | Beaver | 117 min |
Nearby
Flash Flood Warnings in Pennsylvania, 2020Every flash flood warning in 2020
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.