Alert archive / Pennsylvania / Flash Flood Warnings in 2011

Flash Flood Warning 60, NWS State College, PA

September 23, 2011Adams County, Pennsylvania

NWS State College, PA issued this flash flood warning at Sep 23, 2011, 11:46 AM EDT for Adams County, Pennsylvania. It was in force for 6 hr. 4 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
Sep 23, 2011, 11:46 AM EDT (15:46 UTC)
Expired
Sep 23, 2011, 5:45 PM EDT
In force
6 hr
Issued by
NWS State College, PA
Area
Storm-based polygon
Flood severity
None

County Adams County, PA

The radar

The Sterling radar (KLWX), 100 km from the middle of the area, began a volume at 15:46 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.

What was reported inside it

TimeReportWhereRemark
Sep 23, 12:30 PM EDTFLASH FLOODYork Springs, PAWATER OVER ROUTE 94 IN SEVERAL PLACES BETWEEN ROUTE 30 AND ROUTE 15.
Sep 23, 12:31 PM EDTFLASH FLOODGettysburg, PAROADS CLOSED IN AND AROUND GETTYSBURG. LOCAL STREAMS REPORTED OUT OF THEIR BANKS
Sep 23, 1:36 PM EDTFLASH FLOODYork Springs, PA2.47 INCHES OF RAIN IN LESS THAN 2 HOURS.
Sep 23, 5:36 PM EDTFLASH FLOODGettysburg, PAAT 530 PM...APPROXIMATELY 40 ROADS REMAINED CLOSED DUE TO FLOODING IN PRIMARILY CENTRAL AND EASTERN ADAMS CO.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 3.8 hours before the alert went out and 102 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 12:00Z on 2011-09-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 709 joules per kilogram.LCLEL10008507005003002001001 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, Washington/Dulle, VA at 12:00Z on 2011-09-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 54 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
709 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
443 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
54 m²/s²
0-3 km storm-relative helicity
38 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.0

Open this sounding in Storm Lab

The text

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

726 
WGUS51 KCTP 231546
FFWCTP
PAC001-231845-
/O.NEW.KCTP.FF.W.0060.110923T1546Z-110923T1845Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1146 AM EDT FRI SEP 23 2011

THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  ADAMS COUNTY...

* UNTIL 245 PM EDT...

* AT 1143 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR ESTIMATES  
AND RAIN GAGE REPORTS INDICATED VERY HEAVY RAIN WAS FALLING FROM AN 
AREA OF INTENSE SHOWERS AND THUNDERSTORMS OVER ADAMS COUNTY.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO GETTYSBURG.

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!

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 7745 3996 7745 4005 7712 3995 7700
      3974 7702

$$

FORECASTER: LA CORTE
1 follow-up statement
156 
WGUS51 KCTP 231828
FFWCTP
PAC001-232145-
/O.EXT.KCTP.FF.W.0060.000000T0000Z-110923T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
228 PM EDT FRI SEP 23 2011

THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS EXTENDED THE

* FLASH FLOOD WARNING FOR...
  ADAMS COUNTY...

* UNTIL 545 PM EDT...

* AT 223 PM EDT...EMERGENCY PERSONNEL REPORT FLOODING OCCURRING FROM 
HEAVY RAIN OVER ADAMS COUNTY.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  BONNEAUVILLE...CARROLL VALLEY...CASHTOWN...GERMANTOWN...
  GETTYSBURG...HEIDLERSBURG...LITTLESTOWN...MCSHERRYSTOWN...NEW
  OXFORD AND SEVEN STARS.

TRAINED SPOTTERS IN THE AREA REPORT THAT MORE THAN 2 INCHES OF RAIN 
HAS FALLEN. ADDITIONAL SHOWERS AND LOCALLY HEAVY DOWNPOURS CAN BE 
EXPECTED THROUGH LATE AFTERNOON WITH AN INCH OR MORE OF NEW RAIN 
POSSIBLE. NUMEROUS ROADS ARE CLOSED DUE TO THE FLOODING. 

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!

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 7745 3996 7745 4005 7712 3995 7700
      3974 7702

$$

FORECASTER: LA CORTE

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 23, 1:15 AM EDTDense Fog AdvisoryCTPAdams, Bedford, Blair, Cameron, Centre, Clearfield and 24 more9 hr
Sep 23, 9:53 AM EDTFlash Flood WatchCTPAdams, Columbia, Cumberland, Dauphin, Juniata, Lancaster and 10 more16 hr
Sep 23, 11:39 AM EDTAreal Flood AdvisoryCTPAdams, Columbia, Cumberland, Dauphin, Franklin, Lancaster and 5 more6 hr
Sep 23, 1:46 PM EDTFlash Flood WarningCTPSchuylkill3 hr
Sep 23, 1:52 PM EDTAreal Flood AdvisoryCTPColumbia, Cumberland, Dauphin, Juniata, Montour, Northumberland and 4 more6 hr
Sep 23, 2:42 PM EDTFlash Flood WarningCTPDauphin3 hr
Sep 23, 4:04 PM EDTFlash Flood WarningCTPCumberland, York5 hr
Sep 23, 5:35 PM EDTAreal Flood WarningCTPAdams6 hr
Sep 23, 6:16 PM EDTFlash Flood WarningCTPLancaster3 hr
Sep 23, 6:48 PM EDTRiver Flood WarningCTPCumberland, York7 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.