Alert archive / Pennsylvania / Flash Flood Warnings in 2012

Flash Flood Warning 9, NWS Pittsburgh, PA

July 20, 2012Allegheny County, Washington County, Pennsylvania

NWS Pittsburgh, PA issued this flash flood warning at Jul 20, 2012, 2:02 PM EDT for Allegheny County, Washington County, Pennsylvania. It was in force for 5 hr. 18 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
Jul 20, 2012, 2:02 PM EDT (18:02 UTC)
Expired
Jul 20, 2012, 6:57 PM EDT
In force
5 hr
Issued by
NWS Pittsburgh, PA
Area
Storm-based polygon
Flood severity
None

Counties Allegheny County, PA, Washington County, PA

The radar

The Pittsburgh radar (KPBZ), 36 km from the middle of the area, began a volume at 18:03 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
Jul 20, 2:05 PM EDTFLASH FLOOD3 Se Pittsburgh, PART. 51 AT WHITED STREET... A VEHICLE FLOATING IN THE FLOODED ROADWAY. RT. 51 AT LEWIS RUN - FEMALE RESCUED CITY OF PITTSBURGH HAS DEPLOYED THEIR WATER RESCUE TEAMS TO THE AREAS THAT HAVE REPORTED FLOODING
Jul 20, 2:10 PM EDTFLASH FLOOD2 S Pittsburgh, PAROUTE 51 AT EAST BRUCETON ROAD - SHUT DOWN DOWN DUE TO FLOODING
Jul 20, 2:20 PM EDTFLOODImperial, PACLIFF MINE ROAD AND MAHONEY ROAD ARE BOTH CLOSED DUE TO FLOODING.
Jul 20, 2:20 PM EDTFLOODOakdale, PAOAKDALE ROAD CLOSED DUE TO FLOODING
Jul 20, 2:24 PM EDTFLASH FLOODMckeesport, PAROAD FLOODING
Jul 20, 2:26 PM EDTFLASH FLOODWhitehall, PACREEKS OUT OF THEIR BANKS FLOODING ROADWAYS
Jul 20, 2:27 PM EDTFLASH FLOODWest Mifflin, PAWATER RUNNING DOWN ROUTE 51 IN WEST MIFFLIN
Jul 20, 2:31 PM EDTFLASH FLOODBaldwin, PACREEKS OUT OF BANKS AND FLOODING ALONG STREETS RUN ROAD
Jul 20, 3:05 PM EDTFLASH FLOODMckeesport, PACOAL VALLEY ROAD AT CLAIRTON ROAD - REPORTED ROADWAY FLOODING
Jul 20, 3:06 PM EDTFLASH FLOODWhite Oak, PAWHITE OAK - ROADWAY FLOODING - ON E 5TH BETWEEN PENNSYLVANIA AND LINCOLN THERE IS APPROX 4 FOOT OF WATER IN THE ROADWAY.
Jul 20, 3:07 PM EDTFLASH FLOODCarrick, PAROUTE 51 AT BROWNSVILLE ROAD IS COMPLETELY SHUT DOWN BY FLOODING.
Jul 20, 3:08 PM EDTFLASH FLOODDravosburg, PADRAVOSBURG-FLOODING CONDITION ON ROUTE 837.
Jul 20, 3:14 PM EDTFLASH FLOODClairton, PAWORTHINGTON AVE - ROADWAY FLOODED - POSSIBLY 3 FEET OF WATER IN THE ROADWAY.
Jul 20, 3:16 PM EDTFLASH FLOOD2 S Pittsburgh, PATHERE IS A MINUMUM OF 18 MUNICIPALITIES AFFECTED BY THE FLOODING. THE WORST HIT ARES IS THE ROUTE 51 CORRIDOR FRM THE JEFFERSON HILLS LINE TO THE CITY OF PITTSBURGH. ALSO... THE HAYS STREETS RUN ROAD AREA HAS BEEN HARD HIT.
Jul 20, 3:19 PM EDTFLASH FLOOD3 S Robinson Township, PANORTH FAYETTE TOWNSHIP FLOODING ON THE FOLLOWING ROADWAYS. MAHONEY ROAD OAKDALE ROAD
Jul 20, 3:21 PM EDTFLASH FLOODRobinson Township, PACAMPBELLS RUN ROAD FLOODED.
Jul 20, 4:11 PM EDTFLASH FLOODImperial, PAWATER FROM CREEK IN IMPERIAL HAS RUN OUT OF ITS BANKS AND IS FLOODING BRIDGES AND A FEW HOMES
Jul 20, 4:26 PM EDTFLASH FLOODImperial, PAFLOODED HOUSES AND BRIDGES FLOODED NEAR MCCLAREN 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, 6.0 hours before the alert went out and 19 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 2012-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 474 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 2012-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 27 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
474 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
492 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
27 m²/s²
0-3 km storm-relative helicity
44 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.

568 
WGUS51 KPBZ 201802
FFWPBZ
PAC003-125-202100-
/O.NEW.KPBZ.FF.W.0009.120720T1802Z-120720T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PITTSBURGH PA
202 PM EDT FRI JUL 20 2012

THE NATIONAL WEATHER SERVICE IN PITTSBURGH HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHERN ALLEGHENY COUNTY IN SOUTHWEST PENNSYLVANIA...
  NORTHERN WASHINGTON COUNTY IN SOUTHWEST PENNSYLVANIA...

* UNTIL 500 PM EDT

* AT 158 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR AND LOCAL 
RAINFALL GAUGES REPORTED RAINFALL RATES IN EXCESS OF 2.5 INCHES PER 
HOUR. THIS IS LIKELY CAUSING ADDITIONAL RISING WATER OVER LOCAL 
ROADWAYS AND IN LOCAL STREAMS...ESPECIALLY ACROSS SOUTHERN ALLEGHENY 
COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF WILL CAUSE FLOODING OF SMALL STREAMS...LOW LYING
SPOTS ON ROADS...AND POOR DRAINAGE AREAS.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE ROAD.
THE WATER DEPTH MAY BE TOO GREAT FOR SAFE PASSAGE.

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

LAT...LON 4039 7976 4030 7979 4028 7978 4028 7980
      4026 7979 4024 7981 4023 7978 4020 7986
      4017 7985 4015 7991 4023 8049 4041 8050
      4053 8026 4040 7974

$$

FRIES
3 follow-up statements
758 
WGUS71 KPBZ 201846
FFSPBZ
FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PITTSBURGH PA
246 PM EDT FRI JUL 20 2012

PAC003-125-202100-
/O.CON.KPBZ.FF.W.0009.000000T0000Z-120720T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ALLEGHENY PA-WASHINGTON PA-
246 PM EDT FRI JUL 20 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 500 PM EDT FOR
WASHINGTON AND ALLEGHENY COUNTIES...

ALLEGHENY COUNTY EMERGENCY MANAGEMENT ARE REPORTING WIDESPREAD FLASH 
FLOODING ACROSS MUCH OF THE SOUTHERN HALF OF ALLEGHENY COUNTY. THIS 
IS A SERIOUS SITUATION.  THERE HAVE BEEN SEVERAL WATER RESCUES FROM 
VEHICLES. THE CITY OF PITTSBURGH HAS DEPLOYED THEIR WATER RESCUE TEAMS
TO THE AREAS THAT HAVE REPORTED FLOODING.  MUCH OF THE SERIOUS 
FLOODING HAS BEEN ALONG THE ROUTE 51 COORIDOR AND IN THE IMPERIAL 
AREA. 

NEVER DRIVE INTO A FLOODED AREA AND MOVE TO HIGHER GROUND 
IMMEDIATELY IF RISING WATER APPROACH.

RAINFALL RATES OF NEARLY 3 INCHES PER HOUR HAVE BEEN REPORTED.  THE 
TORRENTIAL DOWNPOURS WILL CONTINUE TO MOVE OVER THE SAME AREA 
THROUGH 5PM.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WEST
MIFFLIN...UPPER SAINT CLAIR...TURTLE CREEK...SOUTH SIDE PITTSBURGH...
PITTSBURGH...OAKLAND...OAKDALE...NORTH SIDE PITTSBURGH...MOUNT
WASHINGTON...MOUNT LEBANON...MOON...MCKEESPORT...MCKEES ROCKS...
MCDONALD...IMPERIAL...FLORENCE...CARNEGIE...BURGETTSTOWN...
BRIDGEVILLE...BRENTWOOD...BETHEL PARK AND BALDWIN

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE ROAD.
THE WATER DEPTH MAY BE TOO GREAT FOR SAFE PASSAGE.

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

&&

LAT...LON 4039 7976 4030 7979 4028 7978 4028 7980
      4026 7979 4024 7981 4023 7978 4020 7986
      4017 7985 4015 7991 4023 8049 4041 8050
      4053 8026 4040 7974

$$
361 
WGUS51 KPBZ 202056
FFWPBZ
PAC003-125-210000-
/O.EXT.KPBZ.FF.W.0009.000000T0000Z-120721T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PITTSBURGH PA
456 PM EDT FRI JUL 20 2012

THE NATIONAL WEATHER SERVICE IN PITTSBURGH HAS EXTENDED THE

* FLASH FLOOD WARNING FOR...
  SOUTHERN ALLEGHENY COUNTY IN SOUTHWEST PENNSYLVANIA...
  NORTHERN WASHINGTON COUNTY IN SOUTHWEST PENNSYLVANIA...

* UNTIL 800 PM EDT

* AT 448 PM EDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED FLOODING
ON ROUTE 51 AT THE INTERSECTION WITH ROUTE 88...AND ALONG OTHER PARTS
OF ROUTE 51 IN THE SOUTH HILLS.  ALSO, FLOODED HOMES AND BRIDGES WERE
REPORTED IN IMPERIAL. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE WATER COVERS THE ROAD. FLOOD WATER IS USUALLY DEEPER THAN
IT APPEARS...AND ONE FOOT OF FLOWING WATER IS POWERFUL ENOUGH TO
SWEEP VEHICLES OFF THE ROAD. 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 4039 7976 4030 7979 4028 7978 4028 7980
      4026 7979 4024 7981 4023 7978 4020 7986
      4017 7985 4015 7991 4023 8049 4041 8050
      4053 8026 4040 7974

$$
646 
WGUS71 KPBZ 202257
FFSPBZ

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PITTSBURGH PA
657 PM EDT FRI JUL 20 2012

PAC003-125-202305-
/O.CAN.KPBZ.FF.W.0009.000000T0000Z-120721T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ALLEGHENY PA-WASHINGTON PA-
657 PM EDT FRI JUL 20 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR WASHINGTON AND
ALLEGHENY COUNTIES...

THUNDERSTORMS HAVE MOVED OUT OF THE REGION AND THE FLOODING HAS
SUBSIDED.  REPORTS SAY ALL ROADS HAVE BEEN REOPENED.

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

LAT...LON 4039 7976 4030 7979 4028 7978 4028 7980
      4026 7979 4024 7981 4023 7978 4020 7986
      4017 7985 4015 7991 4023 8049 4041 8050
      4053 8026 4040 7974

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 5:21 AM EDTSpecial Weather StatementPBZAllegheny, Washington, Westmoreland54 min
Jul 20, 6:02 AM EDTAreal Flood AdvisoryPBZAllegheny, Beaver, Fayette, Indiana, Washington, Westmoreland3 hr
Jul 20, 1:31 PM EDTAreal Flood AdvisoryPBZAllegheny, Washington3 hr
Jul 20, 1:57 PM EDTFlash Flood WatchPBZAllegheny, Fayette, Greene, Washington, Westmoreland5 hr
Jul 20, 4:11 PM EDTFlash Flood WarningPBZFayette, Washington, Westmoreland3 hr
Jul 20, 5:34 PM EDTAreal Flood AdvisoryPBZFayette, Greene88 min

Nearby

Flash Flood Warnings in Pennsylvania, 2012Every flash flood warning in 2012

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.