Alert archive / Pennsylvania / Flash Flood Warnings in 2011

Flash Flood Warning 13, NWS Pittsburgh, PA

July 22, 2011Washington County, Pennsylvania

NWS Pittsburgh, PA issued this flash flood warning at Jul 22, 2011, 2:38 PM EDT for Washington 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: Jul 22, 2011, 2:38 PM EDT (18:38 UTC)
Expired: Jul 22, 2011, 5:30 PM EDT
In force: 3 hr
Issued by: NWS Pittsburgh, PA
Area: Storm-based polygon
Flood severity: None

County Washington County, PA

The radar

The Pittsburgh radar (KPBZ), 42 km from the middle of the area, began a volume at 18:40 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, 6.6 hours before the alert went out and 25 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 3887 J/kg
Mixed-layer CIN: -34 J/kg
Mixed-layer LCL: 868 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: -61 m²/s²
0-3 km storm-relative helicity: -29 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

741 
WGUS51 KPBZ 221838
FFWPBZ
PAC125-222130-
/O.NEW.KPBZ.FF.W.0013.110722T1838Z-110722T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PITTSBURGH PA
238 PM EDT FRI JUL 22 2011

THE NATIONAL WEATHER SERVICE IN PITTSBURGH HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EAST CENTRAL WASHINGTON COUNTY IN SOUTHWEST PENNSYLVANIA...

* UNTIL 530 PM EDT

* AT 235 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM REPORTED OVER THE WARNED AREA.

THIS INCLUDES THE BASINS OF MINGO CREEK...SAWMILL CREEK...AND DRY 
RUN.  RAINFALL AT THE RATE OF 1 TO 2 INCHES PER HALF HOUR HAS BEEN 
INDICATED.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

PLEASE REPORT HIGH WATER TO THE NATIONAL WEATHER SERVICE BY CALLING 
TOLL FREE...1-877-633-6772.

LAT...LON 4013 7995 4017 8010 4027 8003 4025 7994
      4024 7995 4024 7997 4022 7998 4021 7994
      4020 7991 4020 7989

$$


15

2 follow-up statements

760 
WGUS71 KPBZ 221922
FFSPBZ

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PITTSBURGH PA
322 PM EDT FRI JUL 22 2011

PAC125-222130-
/O.CON.KPBZ.FF.W.0013.000000T0000Z-110722T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON PA-
322 PM EDT FRI JUL 22 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 530 PM EDT FOR
WASHINGTON COUNTY...

AT 314 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THAT HEAVY RAINFALL HAD ENDED OVER THE WARNED AREA.  RUNOFF FROM THE 
HEAVY RAIN WILL CONTINUE FOR SEVERAL HOURS.

ESTIMATES ARE THAT NEARLY 2 INCHES OF RAIN FELL OVER THE BASINS OF 
MINGO CREEK...SAWMILL CREEK...AND DRY RUN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOST FLOOD RELATED DEATHS OCCUR IN AUTOMOBILES. DO NOT ATTEMPT TO 
CROSS WATER COVERED BRIDGES...DIPS...OR LOW WATER CROSSINGS. NEVER 
TRY TO CROSS A FLOWING STREAM...EVEN A SMALL ONE...ON FOOT. TO 
ESCAPE RISING WATER MOVE UP TO HIGHER GROUND.

&&

LAT...LON 4013 7995 4017 8010 4027 8003 4025 7994
      4024 7995 4024 7997 4022 7998 4021 7994
      4020 7991 4020 7989

$$



15

365 
WGUS71 KPBZ 222035
FFSPBZ

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PITTSBURGH PA
435 PM EDT FRI JUL 22 2011

PAC125-222130-
/O.CON.KPBZ.FF.W.0013.000000T0000Z-110722T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON PA-
435 PM EDT FRI JUL 22 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 530 PM EDT FOR
WASHINGTON COUNTY...

AT 429 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
ANOTHER THUNDERSTORM HAD MOVED OVER THE WARNED AREA.  THIS STORM 
WITH HEAVY RAINFALL WAS LOCATED NEAR MONONGAHELA...MOVING EAST AT 
5 MPH.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

&&

LAT...LON 4013 7995 4017 8010 4027 8003 4025 7994
      4024 7995 4024 7997 4022 7998 4021 7994
      4020 7991 4020 7989

$$



15

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 22, 11:36 AM EDT	Excessive Heat Warning	PBZ	Allegheny, Beaver, Washington	6 hr
Jul 22, 3:49 PM EDT	Special Weather Statement	PBZ	Washington	26 min
Jul 22, 4:58 PM EDT	Special Weather Statement	PBZ	Mercer	47 min
Jul 22, 5:06 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny	39 min
Jul 22, 5:08 PM EDT	Severe Thunderstorm Warning	PBZ	Lawrence, Mercer	37 min
Jul 22, 5:12 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Beaver, Butler, Washington	63 min
Jul 22, 5:17 PM EDT	Severe Thunderstorm Warning	PBZ	Mercer	43 min
Jul 22, 5:19 PM EDT	Severe Thunderstorm Warning	PBZ	Armstrong, Butler, Westmoreland	41 min
Jul 22, 5:45 PM EDT	Severe Thunderstorm Warning	PBZ	Butler, Lawrence, Mercer	47 min
Jul 22, 5:48 PM EDT	Severe Thunderstorm Warning	PBZ	Armstrong, Butler, Clarion, Indiana, Westmoreland	42 min
Jul 22, 6:00 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny	45 min
Jul 22, 6:08 PM EDT	Areal Flood Warning	PBZ	Butler, Lawrence, Mercer	2 hr
Jul 22, 6:15 PM EDT	Areal Flood Warning	PBZ	Allegheny, Armstrong, Butler, Westmoreland	4 hr
Jul 22, 6:26 PM EDT	Special Weather Statement	PBZ	Westmoreland	64 min
Jul 22, 6:41 PM EDT	Special Weather Statement	PBZ	Greene	49 min
Jul 22, 6:48 PM EDT	Severe Thunderstorm Warning	PBZ	Fayette, Greene, Washington	42 min
Jul 22, 7:39 PM EDT	Special Weather Statement	PBZ	Fayette, Greene	66 min
Jul 22, 7:50 PM EDT	Severe Thunderstorm Warning	PBZ	Fayette	40 min

Nearby

Flash Flood Warnings in Pennsylvania, 2011 Every flash flood warning in 2011

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.