Alert archive / Pennsylvania / Flash Flood Warnings in 2011

Flash Flood Warning 79, NWS State College, PA

September 28, 20114 counties in Pennsylvania

NWS State College, PA issued this flash flood warning at Sep 28, 2011, 8:18 PM EDT for 4 counties in 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 28, 2011, 8:18 PM EDT (00:18 UTC)
Expired
Sep 28, 2011, 11:15 PM EDT
In force
3 hr
Issued by
NWS State College, PA
Area
Storm-based polygon
Flood severity
None

Counties Columbia County, PA, Dauphin County, PA, Northumberland County, PA, Schuylkill County, PA

The radar

The State College radar (KCCX), 106 km from the middle of the area, began a volume at 00:19 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 28, 9:00 PM EDTFLASH FLOODElysburg, PAWATER RESCUES...ROADS WASHING OUT...WATER OVER BRIDGES

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 00:00Z, 0.3 hours before the alert went out and 200 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 2011-09-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1614 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 2011-09-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 88 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
1614 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
676 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
88 m²/s²
0-3 km storm-relative helicity
111 m²/s²
Significant tornado parameter
0.6
Supercell composite
3.0

Open this sounding in Storm Lab

The text

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

947 
WGUS51 KCTP 290018
FFWCTP
PAC037-043-097-107-290315-
/O.NEW.KCTP.FF.W.0079.110929T0018Z-110929T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
818 PM EDT WED SEP 28 2011

THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTH CENTRAL COLUMBIA COUNTY...
  NORTHERN DAUPHIN COUNTY...
  WEST CENTRAL SCHUYLKILL COUNTY...
  SOUTHERN NORTHUMBERLAND COUNTY...

* UNTIL 1115 PM EDT...

* AT 814 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR ESTIMATES
  AND RAIN GAGE REPORTS INDICATED VERY HEAVY RAIN FROM A THUNDERSTORM
  OVER NORTHERN DAUPHIN...SOUTH CENTRAL COLUMBIA...SOUTHERN
  NORTHUMBERLAND AND WEST CENTRAL SCHUYLKILL COUNTIES. THAT 
  THUNDERSTORM WILL MOVE THROUGH THE AREA VERY QUICKLY...BUT 
  FLOODING MAY OCCUR VERY QUICKLY AS WELL...SINCE FLOODING FROM 
  EARLIER IN THE DAY HAS ONLY RECENTLY RECEDED.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO KULPMONT...
  SHAMOKIN AND ELYSBURG AS WELL AS GRATZ AND PILLOW.

ADDITIONAL RAINFALL AMOUNTS OF AT LEAST AN INCH ARE POSSIBLE IN THE 
WARNED AREA.

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.

DO NOT UNDERESTIMATE THE POWER OF FLOOD WATERS. ONLY A FEW INCHES OF
RAPIDLY FLOWING WATER CAN QUICKLY CARRY AWAY YOUR VEHICLE.

&&

LAT...LON 4089 7639 4065 7652 4056 7670 4052 7699
      4054 7698 4056 7700 4060 7695 4063 7695
      4070 7686 4077 7685 4078 7686 4088 7680

$$

FORECASTER: DANGELO

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 28, 8:07 PM EDTSpecial Weather StatementCTPColumbia23 min
Sep 28, 8:31 PM EDTSpecial Weather StatementCTPFranklin59 min
Sep 28, 9:26 PM EDTAreal Flood WarningCTPAdams, Columbia, Cumberland, Dauphin, Juniata, Lancaster and 11 more6 hr
Sep 29, 12:41 AM EDTSpecial Weather StatementCTPSchuylkill34 min
Sep 29, 3:28 AM EDTAreal Flood AdvisoryCTPColumbia, Dauphin, Lycoming, Montour, Northumberland, Schuylkill and 3 more4 hr
Sep 29, 10:20 AM EDTRiver Flood WarningCTPCumberland, York10 hr
Sep 29, 11:07 AM EDTSpecial Weather StatementCTPLebanon, York53 min
Sep 29, 11:30 AM EDTAreal Flood AdvisoryCTPColumbia, Dauphin, Lebanon, Lycoming, Montour, Northumberland and 2 more3 hr
Sep 29, 12:20 PM EDTRiver Flood WarningCTPColumbia20 hr
Sep 29, 12:20 PM EDTRiver Flood WarningCTPColumbia, Montour, Northumberland20 hr
Sep 29, 2:19 PM EDTSpecial Weather StatementCTPFranklin41 min
Sep 29, 2:46 PM EDTSpecial Weather StatementCTPColumbia, Montour59 min
Sep 29, 2:48 PM EDTSpecial Weather StatementCTPCumberland, Dauphin42 min
Sep 29, 3:20 PM EDTAreal Flood AdvisoryCTPColumbia, Lycoming, Montour, Northumberland, Sullivan, Tioga3 hr
Sep 29, 3:41 PM EDTSpecial Weather StatementCTPJuniata64 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.