Alert archive / West Virginia / Flash Flood Warnings in 2021

Flash Flood Warning 28, NWS Pittsburgh, PA

August 16, 2021Marion County, Monongalia County, West Virginia; Greene County, Pennsylvania

NWS Pittsburgh, PA issued this flash flood warning at Aug 16, 2021, 6:27 PM EDT for Marion County, Monongalia County, West Virginia; Greene 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 outline as issued.

The facts

Issued
Aug 16, 2021, 6:27 PM EDT (22:27 UTC)
Expired
Aug 16, 2021, 9:30 PM EDT
In force
3 hr
Issued by
NWS Pittsburgh, PA
Area
Storm-based polygon
Flood severity
None

Counties Greene County, PA, Marion County, WV, Monongalia County, WV

The radar

The Pittsburgh radar (KPBZ), 93 km from the middle of the area, began a volume at 22:31 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, 10.5 hours before the alert went out and 79 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-pSkew-T log-p diagram, Pittsburgh, PA at 12:00Z on 2021-08-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 82 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Pittsburgh, PA at 12:00Z on 2021-08-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 53 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
82 J/kg
Mixed-layer CIN
-73 J/kg
Mixed-layer LCL
797 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
53 m²/s²
0-3 km storm-relative helicity
74 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

814 
WGUS51 KPBZ 162227
FFWPBZ
PAC059-WVC049-061-170130-
/O.NEW.KPBZ.FF.W.0028.210816T2227Z-210817T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Pittsburgh PA
627 PM EDT Mon Aug 16 2021

The National Weather Service in Pittsburgh has issued a

* Flash Flood Warning for...
  Southeastern Greene County in southwestern Pennsylvania...
  North Central Marion County in northern West Virginia...
  North Central Monongalia County in northern West Virginia...

* Until 930 PM EDT.

* At 627 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...
  Cassville, Bobtown, Mount Morris, Core, Pentress, McCurdyville and 
  Daybrook.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 3961 8023 3965 8024 3970 8020 3971 8019
      3974 8014 3978 8004 3979 7997 3977 7994
      3974 7996 3971 7999 3967 8004 3958 8017

FLASH FLOOD...RADAR INDICATED

$$

Brown
2 follow-up statements
078 
WGUS71 KPBZ 170026 RRA
FFSPBZ

Flash Flood Statement
National Weather Service Pittsburgh PA
826 PM EDT Mon Aug 16 2021

PAC059-WVC049-061-170130-
/O.CON.KPBZ.FF.W.0028.000000T0000Z-210817T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Greene PA-Marion WV-Monongalia WV-
826 PM EDT Mon Aug 16 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 930 PM EDT THIS 
EVENING FOR SOUTHEASTERN GREENE, NORTH CENTRAL MARION AND NORTH 
CENTRAL MONONGALIA COUNTIES...

At 826 PM EDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 2 and 3.5 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...
  Cassville, Bobtown, Mount Morris, Core, Pentress, McCurdyville and 
  Daybrook.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 3961 8023 3965 8024 3970 8020 3971 8019
      3974 8014 3978 8004 3979 7997 3977 7994
      3974 7996 3971 7999 3967 8004 3958 8017

FLASH FLOOD...RADAR INDICATED

$$

Brown
735 
WGUS71 KPBZ 170126 RRA
FFSPBZ

Flash Flood Statement
National Weather Service Pittsburgh PA
926 PM EDT Mon Aug 16 2021

PAC059-WVC049-061-170136-
/O.EXP.KPBZ.FF.W.0028.000000T0000Z-210817T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Greene PA-Marion WV-Monongalia WV-
926 PM EDT Mon Aug 16 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 930 PM EDT THIS EVENING FOR 
SOUTHEASTERN GREENE, NORTH CENTRAL MARION AND NORTH CENTRAL 
MONONGALIA 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 3961 8023 3965 8024 3970 8020 3971 8019
      3974 8014 3978 8004 3979 7997 3977 7994
      3974 7996 3971 7999 3967 8004 3958 8017

$$

Brown

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 16, 4:17 PM EDTAreal Flood AdvisoryPBZMonongalia77 min
Aug 16, 7:18 PM EDTFlash Flood WarningPBZMarion, Monongalia2 hr

Nearby

Flash Flood Warnings in West Virginia, 2021Flash 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.