Alert archive / Pennsylvania / Flash Flood Warnings in 2012

Flash Flood Warning 2, NWS Pittsburgh, PA

May 7, 2012Mercer County, Pennsylvania

NWS Pittsburgh, PA issued this flash flood warning at May 7, 2012, 10:32 PM EDT for Mercer County, Pennsylvania. It was in force for 4 hr. 1 report 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
May 7, 2012, 10:32 PM EDT (02:32 UTC)
Expired
May 8, 2012, 2:30 AM EDT
In force
4 hr
Issued by
NWS Pittsburgh, PA
Area
Storm-based polygon
Flood severity
None

County Mercer County, PA

The radar

The Pittsburgh radar (KPBZ), 82 km from the middle of the area, began a volume at 02:35 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
May 8, 12:31 AM EDTFLOODHermitage, PABROADWAY AVE CLOSED IN HERMITAGE DUE TO HIGH WATER

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, 2.5 hours before the alert went out and 97 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 2012-05-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 920 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 2012-05-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 121 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
920 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
1102 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
121 m²/s²
0-3 km storm-relative helicity
208 m²/s²
Significant tornado parameter
0.4
Supercell composite
3.2

Open this sounding in Storm Lab

The text

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

069 
WGUS51 KPBZ 080232
FFWPBZ
PAC085-080630-
/O.NEW.KPBZ.FF.W.0002.120508T0232Z-120508T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PITTSBURGH PA
1032 PM EDT MON MAY 7 2012

THE NATIONAL WEATHER SERVICE IN PITTSBURGH HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHERN MERCER COUNTY IN NORTHWEST PENNSYLVANIA...

* UNTIL 230 AM EDT

* AT 1025 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR
  INDICATED MORE RAIN FROM SHOWERS AND THUNDERSTORMS 13 MILES
  SOUTHWEST OF FARRELL...OR ABOUT NEAR YOUNGSTOWN...MOVING NORTHEAST
  AT 30 MPH.

IN ADDITION...COUNTY OFFICIALS REPORTED NUMEROUS WATER COVERED ROADS 
AND SMALL STREAMS OUT OF BANKS.  RADAR ESTIMATES ARE OF 1.5 TO 2.5 
INCHES OF RAIN ACROSS THIS AREA...WITH ANOTHER 0.5 TO 1.0 INCH 
POSSIBLE OVERNIGHT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA...MOVE TO HIGHER GROUND IMMEDIATELY.
PERSONS RESIDING ALONG STREAMS SHOULD TAKE IMMEDIATE ACTION TO
PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS FLOWING WATER OR
WATER OF UNKNOWN DEPTH BY FOOT OR AUTOMOBILE.

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

LAT...LON 4135 8051 4135 8013 4113 8013 4114 8052

$$


15

The office that day

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

IssuedProductOfficeCountiesLasted
May 7, 8:29 PM EDTSevere Thunderstorm WarningPBZLawrence, Mercer46 min
May 7, 8:36 PM EDTSpecial Weather StatementPBZMercer39 min
May 7, 9:24 PM EDTSpecial Weather StatementPBZLawrence, Mercer51 min
May 7, 9:33 PM EDTAreal Flood AdvisoryPBZMercer3 hr
May 7, 10:11 PM EDTSpecial Weather StatementPBZAllegheny34 min
May 8, 12:09 AM EDTAreal Flood AdvisoryPBZButler3 hr
May 8, 7:22 AM EDTFlood WatchPBZAllegheny, Armstrong, Beaver, Butler, Clarion, Forest and 5 more5 hr
May 8, 6:47 PM EDTSpecial Weather StatementPBZWestmoreland58 min
May 8, 7:53 PM EDTFlash Flood WarningPBZWestmoreland3 hr

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.