Alert archive / Pennsylvania / Flash Flood Warnings in 2011

Flash Flood Warning 57, NWS State College, PA

September 11, 2011York County, Pennsylvania

NWS State College, PA issued this flash flood warning at Sep 11, 2011, 7:51 PM EDT for York County, Pennsylvania. It was in force for 3 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
Sep 11, 2011, 7:51 PM EDT (23:51 UTC)
Expired
Sep 11, 2011, 10:45 PM EDT
In force
3 hr
Issued by
NWS State College, PA
Area
Storm-based polygon
Flood severity
None

County York County, PA

The radar

The Sterling radar (KLWX), 114 km from the middle of the area, began a volume at 23:53 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 11, 7:54 PM EDTFLASH FLOOD1 E East Berlin, PAREPORT OF A VEHICLE STRANDED IN HIGH WATER IN PARADISE TWP NEAR EAST BERLIN.

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, 11.9 hours before the alert went out and 114 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 2011-09-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 485 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, Washington/Dulle, VA at 12:00Z on 2011-09-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 31 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
485 J/kg
Mixed-layer CIN
-41 J/kg
Mixed-layer LCL
891 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
31 m²/s²
0-3 km storm-relative helicity
115 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.7

Open this sounding in Storm Lab

The text

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

044 
WGUS51 KCTP 112351
FFWCTP
PAC133-120245-
/O.NEW.KCTP.FF.W.0057.110911T2351Z-110912T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
751 PM EDT SUN SEP 11 2011

THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CENTRAL YORK COUNTY...

* UNTIL 1045 PM EDT...

* AT 747 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  VERY HEAVY RAIN FROM TRAINING SHOWERS AND THUNDERSTORMS OVER
  WEST CENTRAL AND CENTRAL YORK COUNTY. RADAR ESTIMATES OF BETWEEN
  ONE AND TWO INCHES ARE COMMON IN THIS AREA...AND ADDITIONAL 
  UPSTREAM RAINFALL COULD PRODUCE LOCAL TOTALS IN EXCESS OF 3
  INCHES. THEREFORE FLASH FLOODING IS EXPECTED TO BEGIN SHORTLY.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO SPRING
  GROVE...THOMASVILLE AND YORK.

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.

&&

LAT...LON 3986 7695 3989 7699 3992 7697 3999 7701
      3998 7674 3992 7670 3985 7673 3985 7696
      3985 7697

$$

FORECASTER: DEVOIR
1 follow-up statement
428 
WGUS71 KCTP 120152
FFSCTP

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
952 PM EDT SUN SEP 11 2011

PAC133-120245-
/O.CON.KCTP.FF.W.0057.000000T0000Z-110912T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
YORK PA-
952 PM EDT SUN SEP 11 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1045 PM EDT FOR
CENTRAL YORK COUNTY...

AT 946 PM EDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED SOME ROADS 
REMAINED FLOODED FROM THUNDERSTORMS THAT HAVE SINCE EXITED THE AREA. 

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO PARADISE 
TOWNSHIP. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

&&

LAT...LON 3986 7695 3989 7699 3992 7697 3999 7701
      3998 7674 3992 7670 3985 7673 3985 7696
      3985 7697

$$

FORECASTER:

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 11, 9:01 AM EDTAreal Flood AdvisoryCTPSullivan3 hr
Sep 11, 4:46 PM EDTSpecial Weather StatementCTPCumberland44 min
Sep 11, 4:54 PM EDTAreal Flood AdvisoryCTPAdams3 hr
Sep 11, 5:04 PM EDTAreal Flood AdvisoryCTPCumberland3 hr
Sep 11, 5:29 PM EDTSpecial Weather StatementCTPYork31 min
Sep 11, 5:53 PM EDTSevere Thunderstorm WarningCTPLancaster, York67 min
Sep 11, 6:18 PM EDTSpecial Weather StatementCTPCentre42 min
Sep 11, 6:38 PM EDTSpecial Weather StatementCTPCentre52 min
Sep 11, 6:50 PM EDTAreal Flood AdvisoryCTPAdams, Cumberland, Dauphin, Franklin, York3 hr
Sep 11, 7:12 PM EDTSpecial Weather StatementCTPYork48 min
Sep 11, 7:13 PM EDTSpecial Weather StatementCTPFranklin47 min
Sep 11, 7:16 PM EDTSpecial Weather StatementCTPAdams44 min
Sep 11, 7:17 PM EDTSpecial Weather StatementCTPAdams43 min
Sep 11, 7:31 PM EDTFlash Flood WarningCTPAdams3 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.