Alert archive / Pennsylvania / Flash Flood Warnings in 2011

Flash Flood Warning 38, NWS State College, PA

September 4, 20117 counties in Pennsylvania

NWS State College, PA issued this flash flood warning at Sep 4, 2011, 11:44 PM EDT for 7 counties in 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
Sep 4, 2011, 11:44 PM EDT (03:44 UTC)
Expired
Sep 5, 2011, 2:45 AM EDT
In force
3 hr
Issued by
NWS State College, PA
Area
Storm-based polygon
Flood severity
None

Counties Adams County, PA, Cumberland County, PA, Dauphin County, PA, Lancaster County, PA, Lebanon County, PA, Perry County, PA, York County, PA

The radar

The State College radar (KCCX), 131 km from the middle of the area, began a volume at 03:46 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

Washington/Dulle, VA (KIAD), launched 00:00Z, 3.7 hours before the alert went out and 141 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, Washington/Dulle, VA at 00:00Z on 2011-09-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2382 joules per kilogram.LCLEL10008507005003002001001 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, Washington/Dulle, VA at 00:00Z on 2011-09-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 63 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
2382 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
895 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
63 m²/s²
0-3 km storm-relative helicity
64 m²/s²
Significant tornado parameter
0.3
Supercell composite
2.2

Open this sounding in Storm Lab

The text

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

551 
WGUS51 KCTP 050344
FFWCTP
PAC001-041-043-071-075-099-133-050645-
/O.NEW.KCTP.FF.W.0038.110905T0344Z-110905T0645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1144 PM EDT SUN SEP 4 2011

THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EASTERN ADAMS COUNTY...
  NORTHEASTERN CUMBERLAND COUNTY...
  DAUPHIN COUNTY...
  WEST CENTRAL LANCASTER COUNTY...
  WESTERN LEBANON COUNTY...
  NORTHEASTERN PERRY COUNTY...
  YORK COUNTY...

* UNTIL 245 AM EDT...

* AT 900 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  VERY HEAVY RAIN FROM THUNDERSTORMS MOVING INTO DAUPHIN...EASTERN   
  ADAMS...NORTHEASTERN CUMBERLAND...NORTHEASTERN PERRY...WEST        
  CENTRAL LANCASTER...WESTERN LEBANON AND YORK COUNTIES.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  DALLASTOWN...HANOVER...PARKVILLE...SPRY...WEIGELSTOWN...YORK...
  ELIZABETHTOWN...CAMP HILL...ENOLA...LEMOYNE...LOWER ALLEN...
  MECHANICSBURG...NEW CUMBERLAND...PALMYRA...COLONIAL PARK...
  HARRISBURG...HERSHEY...HUMMELSTOWN...LINGLESTOWN...MIDDLETOWN...
  PROGRESS AND STEELTON.

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.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. NEVER ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR IN AN
AUTOMOBILE. TURN AROUND DON'T DROWN!

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS
SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

FLOODING IS OCCURRING OR IS IMMINENT. MOST FLOOD RELATED DEATHS OCCUR
IN AUTOMOBILES. DO NOT ATTEMPT TO CROSS WATER COVERED BRIDGES...
DIPS...OR LOW WATER CROSSINGS. TURN AROUND...DON'T DROWN! NEVER TRY
TO CROSS A FLOWING STREAM...EVEN A SMALL ONE...ON FOOT. TO ESCAPE
RISING WATER MOVE UP TO HIGHER GROUND.

&&

LAT...LON 3972 7718 4061 7698 4057 7656 4051 7647
      3972 7668

$$

FORECASTER: KF

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 4, 8:11 PM EDTAreal Flood AdvisoryCTPColumbia, Montour, Northumberland, Snyder, Union3 hr
Sep 4, 8:21 PM EDTSpecial Weather StatementCTPAdams, Cumberland, Dauphin, Franklin, Perry54 min
Sep 4, 9:11 PM EDTSpecial Weather StatementCTPAdams, Columbia, Cumberland, Dauphin, Lebanon, Northumberland and 3 more64 min
Sep 4, 9:51 PM EDTAreal Flood AdvisoryCTPCumberland, Dauphin, Lebanon, Northumberland, Perry, Schuylkill and 1 more3 hr
Sep 4, 10:11 PM EDTSpecial Weather StatementCTPColumbia, Dauphin, Lebanon, Schuylkill64 min
Sep 4, 10:14 PM EDTSpecial Weather StatementCTPAdams, Cumberland, Franklin, York61 min
Sep 4, 10:31 PM EDTSevere Thunderstorm WarningCTPLancaster, Lebanon, Schuylkill44 min
Sep 4, 10:54 PM EDTAreal Flood AdvisoryCTPAdams, Cumberland, Franklin, Juniata, Perry, Snyder and 1 more3 hr
Sep 4, 11:29 PM EDTFlash Flood WatchCTPAdams, Columbia, Cumberland, Dauphin, Franklin, Juniata and 12 more21 hr
Sep 4, 11:35 PM EDTSpecial Weather StatementCTPAdams, Dauphin, Lebanon, York70 min
Sep 5, 12:38 AM EDTSpecial Weather StatementCTPYork67 min
Sep 5, 12:45 AM EDTAreal Flood AdvisoryCTPColumbia, Dauphin, Montour, Northumberland, Schuylkill4 hr
Sep 5, 1:41 AM EDTFlash Flood WarningCTPColumbia, Dauphin, Lebanon, Lycoming, Montour, Northumberland and 2 more4 hr
Sep 5, 6:16 PM EDTSpecial Weather StatementCTPLancaster29 min

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.