Alert archive / Pennsylvania / Flash Flood Warnings in 2011

Flash Flood Warning 2, NWS Pittsburgh, PA

February 28, 2011Allegheny County, Pennsylvania

NWS Pittsburgh, PA issued this flash flood warning at Feb 28, 2011, 8:04 AM EST for Allegheny County, Pennsylvania. It was in force for 4 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
Feb 28, 2011, 8:04 AM EST (13:04 UTC)
Expired
Feb 28, 2011, 11:50 AM EST
In force
4 hr
Issued by
NWS Pittsburgh, PA
Area
Storm-based polygon
Flood severity
None

County Allegheny County, PA

The radar

The Pittsburgh radar (KPBZ), 31 km from the middle of the area, began a volume at 13:05 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
Feb 28, 8:57 AM ESTFLOODTarentum, PABULL CREEK IS OUT OF ITS BANKS AND CAUSING FLOODING IN A NUMBER OF BUILDINGS.
Feb 28, 10:30 AM ESTFLOODPittsburgh, PAROUTE 28 NORTHBOUND CLOSED DUE TO FLOODING BETWEEN 31ST AND 40TH STREET BRIDGES
Feb 28, 11:00 AM ESTFLASH FLOODRoss Township, PAMCKNIGHT ROAD CLOSED FOR 3 HOURS - WATER LIFTED MAHOLE COVERS FROM ROAD.

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, 1.1 hours before the alert went out and 18 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 2011-02-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 150 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 2011-02-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 333 square meters per square second.1939587897Sfc1 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
150 J/kg
Mixed-layer CIN
-38 J/kg
Mixed-layer LCL
667 m above ground
0-6 km bulk shear
68 kt
0-1 km storm-relative helicity
333 m²/s²
0-3 km storm-relative helicity
386 m²/s²
Significant tornado parameter
0.4
Supercell composite
1.7

Open this sounding in Storm Lab

The text

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

742 
WGUS51 KPBZ 281304
FFWPBZ
PAC003-281700-
/O.NEW.KPBZ.FF.W.0002.110228T1304Z-110228T1700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PITTSBURGH PA
804 AM EST MON FEB 28 2011

THE NATIONAL WEATHER SERVICE IN PITTSBURGH HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  ALLEGHENY COUNTY IN SOUTHWEST PENNSYLVANIA...

* UNTIL NOON EST

* AT 756 AM EST... RUNOFF FROM HEAVY RAINS IS CAUSING FLASH FLOODING 
ACROSS ALLEGHENY COUNTY.  GIRTYS RUN IN THE ETNA AREA HAS RISEN 3 
FEET OVER THE PAST 30 MINUTES.  HEAVY RAIN IN THE LITTLE PINE CREEK 
AND DEEK CREEK WATERSHED IS CAUSING RAPID RISES. FLOODING WAS ALSO 
REPORTED IN THE ROSS TOWNSHIP AREA WITH ROADS CLOSED.  MANY ROADWAYS 
AND BASEMENTS ARE FLOODED IN WEST DEER TOWENSHIP.    FLASH FLOODING 
IS LIKELY ACROSS ALL OF ALLEGHENY COUNTY.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATER IS USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

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

LAT...LON 4062 7971 4059 7978 4056 7978 4053 7971
      4043 7971 4038 7977 4030 7981 4029 7978
      4022 7980 4021 7982 4020 7991 4022 7997
      4024 7997 4025 7993 4033 8018 4048 8036
      4062 8015 4067 8014 4066 7970

$$
2 follow-up statements
390 
WGUS71 KPBZ 281351
FFSPBZ

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PITTSBURGH PA
851 AM EST MON FEB 28 2011

PAC003-281700-
/O.CON.KPBZ.FF.W.0002.000000T0000Z-110228T1700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ALLEGHENY PA-
851 AM EST MON FEB 28 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL NOON EST FOR
ALLEGHENY COUNTY...

AT 850 AM EST...RUNOFF FROM HEAVY RAINS CONTINUE TO CAUSE FLASH 
FLOODING ACROSS ALLEGHENY COUNTY.  MT NEBO ROAD IN OHIO TOWNSHIP IS 
FLOODED.  ROADWAY FLOODING IS REPORTED IN RICHLAND AND SPRINGDALE 
TOWNSHIP. BASEMENT FLOODING WAS REPORTED IN SHALER...EMSWORTH AND 
FOX CHAPEL.  FLOODING WAS ALSO REPORTED IN THE BELLEVUE AREA AND 
TARENTUM. GIRTYS RUN HAS RISEN 5 FEET SINCE 7 AM.  THE STAGE ON PINE 
CREEK IN THE ETNA AREA HAS RISEN TO 12 FEET.  FLOODING WILL OCCUR 
ALONG PINE CREEK.    


PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. WHEN ENCOUNTERING FLOODED 
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

&&

LAT...LON 4062 7971 4059 7978 4056 7978 4053 7971
      4043 7971 4038 7977 4030 7981 4029 7978
      4022 7980 4021 7982 4020 7991 4022 7997
      4024 7997 4025 7993 4033 8018 4048 8036
      4062 8015 4067 8014 4066 7970

$$
788 
WGUS71 KPBZ 281650
FFSPBZ

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PITTSBURGH PA
1150 AM EST MON FEB 28 2011

PAC003-281657-
/O.CAN.KPBZ.FF.W.0002.000000T0000Z-110228T1700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ALLEGHENY PA-
1150 AM EST MON FEB 28 2011

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR ALLEGHENY COUNTY...

THE FLASH FLOOD WARNING HAS BEEN CANCELED FOR ALLEGHENY COUNTY.  THE 
THREAT FOR FLASH FLOODING HAS ENDED...BUT THIS DOES NOT MEAN THAT 
FLOODING IS OVER.   AN AREAL FLOOD WARNING IS STILL IN EFFECT 
THOUGHOUT THE COUNTY AS FLOODING CONTINUES IN MANY AREAS.  

LAT...LON 4062 7971 4059 7978 4056 7978 4053 7971
      4043 7971 4038 7977 4030 7981 4029 7978
      4022 7980 4021 7982 4020 7991 4022 7997
      4024 7997 4025 7993 4033 8018 4048 8036
      4062 8015 4067 8014 4066 7970

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 27, 8:34 PM ESTSpecial Weather StatementPBZGreene56 min
Feb 27, 9:04 PM ESTSpecial Weather StatementPBZBeaver, Washington56 min
Feb 27, 9:34 PM ESTSevere Thunderstorm WarningPBZAllegheny, Greene, Washington, Westmoreland41 min
Feb 27, 10:03 PM ESTSpecial Weather StatementPBZAllegheny, Beaver, Butler, Lawrence, Westmoreland57 min
Feb 28, 2:00 AM ESTSpecial Weather StatementPBZArmstrong, Beaver, Butler, Clarion, Forest, Jefferson and 3 more60 min
Feb 28, 3:18 AM ESTSpecial Weather StatementPBZArmstrong, Beaver, Butler, Clarion, Forest, Jefferson and 3 more57 min
Feb 28, 4:16 AM ESTAreal Flood WarningPBZForest, Mercer, Venango20 hr
Feb 28, 4:33 AM ESTSpecial Weather StatementPBZBeaver, Butler, Lawrence, Washington27 min
Feb 28, 5:17 AM ESTAreal Flood WarningPBZBeaver, Butler, Lawrence20 hr
Feb 28, 5:23 AM ESTSpecial Weather StatementPBZLawrence, Mercer22 min
Feb 28, 5:44 AM ESTSpecial Weather StatementPBZArmstrong, Beaver, Butler, Lawrence, Mercer61 min
Feb 28, 6:01 AM ESTSevere Thunderstorm WarningPBZAllegheny, Armstrong, Beaver, Butler, Westmoreland29 min
Feb 28, 6:32 AM ESTSpecial Weather StatementPBZAllegheny, Armstrong, Clarion, Indiana, Jefferson, Westmoreland28 min
Feb 28, 6:39 AM ESTAreal Flood WarningPBZClarion, Jefferson15 hr
Feb 28, 6:45 AM ESTSpecial Weather StatementPBZGreene, Washington60 min
Feb 28, 6:46 AM ESTAreal Flood WarningPBZAllegheny, Westmoreland11 hr
Feb 28, 7:24 AM ESTSevere Thunderstorm WarningPBZAllegheny, Fayette, Greene, Washington, Westmoreland51 min
Feb 28, 8:14 AM ESTAreal Flood WarningPBZArmstrong, Indiana, Westmoreland10 hr
Feb 28, 10:19 AM ESTAreal Flood WarningPBZFayette6 hr
Feb 28, 10:52 AM ESTRiver Flood WatchPBZAllegheny30 hr
Feb 28, 10:52 AM ESTRiver Flood WatchPBZAllegheny30 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2011Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.