Alert archive / Pennsylvania / Flash Flood Warnings in 2021

Flash Flood Warning 41, NWS Pittsburgh, PA

September 1, 2021Armstrong County, Indiana County, Westmoreland County, Pennsylvania

NWS Pittsburgh, PA issued this flash flood warning at Sep 1, 2021, 7:16 AM EDT for Armstrong County, Indiana County, Westmoreland County, Pennsylvania. It was in force for 6 hr. 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
Sep 1, 2021, 7:16 AM EDT (11:16 UTC)
Expired
Sep 1, 2021, 1:15 PM EDT
In force
6 hr
Issued by
NWS Pittsburgh, PA
Area
Storm-based polygon
Flood severity
None

Counties Armstrong County, PA, Indiana County, PA, Westmoreland County, PA

The radar

The Pittsburgh radar (KPBZ), 93 km from the middle of the area, began a volume at 11:17 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

TimeReportWhereRemark
Sep 1, 8:15 AM EDTFLASH FLOODHeshbon, PACOUNTY OFFICIALS REPORT FLOODED ROADWAYS ACROSS INDIANA COUNTY... INCLUDING THE TOWNSHIP OF WEST WHEATFIELD.
Sep 1, 8:18 AM EDTFLASH FLOODIndiana, PACOUNTY OFFICIALS REPORT FLOODED ROADWAYS ACROSS INDIANA COUNTY... INCLUDING THE TOWN OF INDIANA
Sep 1, 8:55 AM EDTFLASH FLOODBairdstown, PAFLOODING AT THE BAIRDSTOWN ROAD EXIT TO ROUTE 22

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, 11.3 hours before the alert went out and 86 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 00:00Z on 2021-09-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 43 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 00:00Z on 2021-09-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 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
43 J/kg
Mixed-layer CIN
-46 J/kg
Mixed-layer LCL
816 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
23 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

754 
WGUS51 KPBZ 011116
FFWPBZ
PAC005-063-129-011715-
/O.NEW.KPBZ.FF.W.0041.210901T1116Z-210901T1715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Pittsburgh PA
716 AM EDT Wed Sep 1 2021

The National Weather Service in Pittsburgh has issued a

* Flash Flood Warning for...
  East Central Westmoreland County in southwestern Pennsylvania...
  East Central Armstrong County in west central Pennsylvania...
  Indiana County in west central Pennsylvania...

* Until 115 PM EDT.

* At 716 AM EDT, Doppler radar indicated heavy rain across the 
  warned area. Between 1 and 1.5 inches of rain have fallen. 
  Additional rainfall amounts of 1.5 to 3 inches are possible in the 
  warned area. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by heavy rain.

  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...
  Indiana, Homer City, Blairsville, Black Lick, Clymer, Rural 
  Valley, West Lebanon, New Florence, Chevy Chase Heights, Seward, 
  Ernest, Marion Center, Cherry Tree, Creekside, Plumville, Glen 
  Campbell, Armagh, Atwood, Lucerne Mines and Dixonville.

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 4052 7945 4065 7929 4079 7937 4084 7914
      4084 7881 4077 7881 4072 7880 4072 7881
      4047 7893 4037 7899 4042 7926 4047 7942

FLASH FLOOD...RADAR INDICATED

$$

SH
4 follow-up statements
383 
WGUS71 KPBZ 011221
FFSPBZ

Flash Flood Statement
National Weather Service Pittsburgh PA
821 AM EDT Wed Sep 1 2021

PAC005-063-129-011715-
/O.CON.KPBZ.FF.W.0041.000000T0000Z-210901T1715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Armstrong PA-Indiana PA-Westmoreland PA-
821 AM EDT Wed Sep 1 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 115 PM EDT THIS 
AFTERNOON FOR EAST CENTRAL WESTMORELAND, EAST CENTRAL ARMSTRONG AND 
INDIANA COUNTIES...

At 821 AM EDT, local law enforcement reported heavy rain in Indiana 
. Between 1.5 and 2 inches of rain have fallen. Additional rainfall 
amounts of 1.5 to 3 inches are possible in the warned area. Flash 
flooding is already occurring.

HAZARD...Flash flooding caused by heavy rain.

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...
  Indiana, Homer City, Blairsville, Black Lick, Clymer, Rural 
  Valley, West Lebanon, New Florence, Chevy Chase Heights, Seward, 
  Ernest, Marion Center, Cherry Tree, Creekside, Plumville, Glen 
  Campbell, Armagh, Atwood, Lucerne Mines and Dixonville.

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 4052 7945 4065 7929 4079 7937 4084 7914
      4084 7881 4077 7881 4072 7880 4072 7881
      4047 7893 4037 7899 4042 7926 4047 7942

FLASH FLOOD...OBSERVED

$$

SH
285 
WGUS71 KPBZ 011502
FFSPBZ

Flash Flood Statement
National Weather Service Pittsburgh PA
1102 AM EDT Wed Sep 1 2021

PAC005-063-129-011715-
/O.CON.KPBZ.FF.W.0041.000000T0000Z-210901T1715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Armstrong PA-Indiana PA-Westmoreland PA-
1102 AM EDT Wed Sep 1 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 115 PM EDT THIS 
AFTERNOON FOR EAST CENTRAL WESTMORELAND, EAST CENTRAL ARMSTRONG AND 
INDIANA COUNTIES...

At 1102 AM EDT, local law enforcement reported heavy rain in Indiana 
. Between 2 and 3.5 inches of rain have fallen. Additional rainfall 
amounts of 0.5 to 1 inch are possible in the warned area. Flash 
flooding is already occurring.

HAZARD...Flash flooding caused by heavy rain.

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...
  Indiana, Homer City, Blairsville, Black Lick, Clymer, Rural 
  Valley, West Lebanon, New Florence, Chevy Chase Heights, Seward, 
  Ernest, Marion Center, Cherry Tree, Creekside, Plumville, Glen 
  Campbell, Armagh, Atwood, Lucerne Mines and Dixonville.

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 4052 7945 4065 7929 4079 7937 4084 7914
      4084 7881 4077 7881 4072 7880 4072 7881
      4047 7893 4037 7899 4042 7926 4047 7942

FLASH FLOOD...OBSERVED

$$

SH
620 
WGUS71 KPBZ 011602
FFSPBZ

Flash Flood Statement
National Weather Service Pittsburgh PA
1202 PM EDT Wed Sep 1 2021

PAC005-011612-
/O.CAN.KPBZ.FF.W.0041.000000T0000Z-210901T1715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Armstrong PA-
1202 PM EDT Wed Sep 1 2021

...FLASH FLOOD WARNING IS CANCELLED FOR EAST CENTRAL ARMSTRONG 
COUNTY...

High water is receding. Please continue to heed remaining road 
closures.

A Flash Flood Watch remains in effect until 200 AM EDT Thursday for 
Portions of Pennsylvania. Portions of northern West Virginia.

LAT...LON 4052 7945 4071 7920 4081 7909 4084 7881
      4072 7880 4072 7881 4048 7893 4037 7899
      4042 7926 4047 7942

$$

PAC063-129-011715-
/O.CON.KPBZ.FF.W.0041.000000T0000Z-210901T1715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Indiana PA-Westmoreland PA-
1202 PM EDT Wed Sep 1 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 115 PM EDT THIS 
AFTERNOON FOR EAST CENTRAL WESTMORELAND AND INDIANA COUNTIES...

At 1202 PM EDT, local law enforcement reported heavy rain in Indiana 
. Between 2 and 3.5 inches of rain have fallen. Additional rainfall 
amounts of 0.5 to 1 inch are possible in the warned area. Flash 
flooding is already occurring.

HAZARD...Flash flooding caused by heavy rain.

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...
  Indiana, Homer City, Blairsville, Black Lick, Clymer, New 
  Florence, Chevy Chase Heights, Seward, Ernest, Marion Center, 
  Cherry Tree, Creekside, Glen Campbell, Armagh, Lucerne Mines, 
  Dixonville, Commodore, Jacksonville, Brush Vly and Yellow Creek 
  State Park.

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 4052 7945 4071 7920 4081 7909 4084 7881
      4072 7880 4072 7881 4048 7893 4037 7899
      4042 7926 4047 7942

FLASH FLOOD...OBSERVED

$$

SH
098 
WGUS71 KPBZ 011722
FFSPBZ

Flash Flood Statement
National Weather Service Pittsburgh PA
122 PM EDT Wed Sep 1 2021

PAC063-129-011732-
/O.EXP.KPBZ.FF.W.0041.000000T0000Z-210901T1715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Indiana PA-Westmoreland PA-
122 PM EDT Wed Sep 1 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR EAST CENTRAL WESTMORELAND AND 
INDIANA COUNTIES...

The flash flood warning has been replaced with a base flood warning. 
Flooding is still occuring.

LAT...LON 4052 7945 4071 7920 4081 7909 4084 7881
      4072 7880 4072 7881 4048 7893 4037 7899
      4042 7926 4047 7942

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 1, 5:05 AM EDTAreal Flood AdvisoryPBZAllegheny, Beaver, Fayette, Washington, Westmoreland104 min
Sep 1, 6:23 AM EDTFlash Flood WarningPBZAllegheny, Armstrong, Beaver, Butler, Indiana, Washington and 1 more5 hr
Sep 1, 7:21 AM EDTFlash Flood WarningPBZFayette, Greene6 hr
Sep 1, 7:50 AM EDTFlash Flood WarningPBZWashington3 hr
Sep 1, 9:27 AM EDTFlash Flood WarningPBZAllegheny, Armstrong, Fayette, Greene, Indiana, Washington and 1 more4 hr
Sep 1, 10:26 AM EDTAreal Flood AdvisoryPBZWashington109 min
Sep 1, 11:23 AM EDTAreal Flood AdvisoryPBZAllegheny, Armstrong, Beaver, Butler, Indiana, Washington and 1 more52 min
Sep 1, 11:30 AM EDTRiver Flood WarningPBZIndiana, Westmoreland16 hr
Sep 1, 11:30 AM EDTRiver Flood WarningPBZFayette39 hr
Sep 1, 11:30 AM EDTRiver Flood WarningPBZFayette, Washington, Westmoreland28 hr
Sep 1, 11:30 AM EDTRiver Flood WarningPBZAllegheny, Westmoreland40 hr
Sep 1, 11:30 AM EDTRiver Flood WarningPBZAllegheny, Washington, Westmoreland33 hr
Sep 1, 1:15 PM EDTAreal Flood WarningPBZFayette2 hr
Sep 1, 1:16 PM EDTAreal Flood WarningPBZIndiana, Westmoreland2 hr
Sep 1, 1:24 PM EDTAreal Flood WarningPBZFayette, Indiana, Westmoreland2 hr

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.