Alert archive / Pennsylvania / Flash Flood Warnings in 2010

Flash Flood Warning 21, NWS Pittsburgh, PA

August 1, 2010Clarion County, Pennsylvania

NWS Pittsburgh, PA issued this flash flood warning at Aug 1, 2010, 5:46 AM EDT for Clarion 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
Aug 1, 2010, 5:46 AM EDT (09:46 UTC)
Expired
Aug 1, 2010, 8:45 AM EDT
In force
3 hr
Issued by
NWS Pittsburgh, PA
Area
Storm-based polygon
Flood severity
None

County Clarion County, PA

The radar

The Pittsburgh radar (KPBZ), 105 km from the middle of the area, began a volume at 09:48 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 00:00Z, 9.8 hours before the alert went out and 108 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 2010-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Pittsburgh, PA at 00:00Z on 2010-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -7 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1911 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
-7 m²/s²
0-3 km storm-relative helicity
41 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.

816 
WGUS51 KPBZ 010946
FFWPBZ
PAC031-011245-
/O.NEW.KPBZ.FF.W.0021.100801T0946Z-100801T1245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PITTSBURGH PA
546 AM EDT SUN AUG 1 2010

THE NATIONAL WEATHER SERVICE IN PITTSBURGH HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EAST CENTRAL CLARION COUNTY IN WEST CENTRAL PENNSYLVANIA...

* UNTIL 845 AM EDT

* AT 539 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A STATIONARY THUNDERSTORM NEAR THE TOWN OF
  MECHANICSVILLE.  RADAR ESTIMATES THAT APPROXIMATELY TWO AND A HALF
  TO THREE INCHES OF RAIN HAD FALLEN AS OF 545 AM.

THIS RAIN IS OCCURRING OVER THE BRUSH RUN BASIN...A SMALL AREA NEAR 
INTERSTATE 80 THROUGH EASTERN CLARION COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

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 4120 7931 4119 7928 4115 7928 4114 7933
      4118 7937

$$



15
1 follow-up statement
701 
WGUS71 KPBZ 011021
FFSPBZ

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PITTSBURGH PA
621 AM EDT SUN AUG 1 2010

PAC031-011245-
/O.CON.KPBZ.FF.W.0021.000000T0000Z-100801T1245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARION PA-
621 AM EDT SUN AUG 1 2010

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 845 AM EDT FOR
CLARION COUNTY...

AT 617 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A CLUSTER OF SLOW MOVING SHOWERS PRODUCING VERY HEAVY RAIN 
OVER THE WARNED AREA.  RADAR INDICATED THAT APPROXIMATELY TWO AND A 
HALF TO THREE INCHES OF RAIN HAS FALLEN OVER THE BRUSH RUN BASIN 
NEAR THE TOWN OF MECHANICSVILLE.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL 
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

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

&&

LAT...LON 4120 7931 4119 7928 4115 7928 4114 7933
      4118 7937

$$



15

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 1, 5:02 AM EDTSpecial Weather StatementPBZClarion58 min
Aug 1, 5:24 AM EDTSpecial Weather StatementPBZClarion51 min
Aug 1, 7:41 AM EDTFlash Flood WarningPBZClarion3 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2010Every flash flood warning in 2010

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.