Alert archive / Pennsylvania / Flash Flood Warnings in 2011

Flash Flood Warning 52, NWS State College, PA

September 9, 20114 counties in Pennsylvania

NWS State College, PA issued this flash flood warning at Sep 9, 2011, 10:08 PM EDT for 4 counties in Pennsylvania. It was in force for 3 hr. 2 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 9, 2011, 10:08 PM EDT (02:08 UTC)
Expired
Sep 10, 2011, 1:00 AM EDT
In force
3 hr
Issued by
NWS State College, PA
Area
Storm-based polygon
Flood severity
None

Counties Juniata County, PA, Mifflin County, PA, Perry County, PA, Snyder County, PA

The radar

The State College radar (KCCX), 68 km from the middle of the area, began a volume at 02:08 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 9, 10:08 PM EDTFLASH FLOODIckesburg, PA911 CENTER REPORTED FLASH FLOODING THROUGHOUT MIFFINLTOWN AND PORT ROYAL. ICKESBURG FIRE CO CANNOT LEAVE STATION DUE TO FLASH FLOODING.
Sep 9, 11:00 PM EDTFLASH FLOODPort Royal, PASEVERAL WATER RESCUES IN PORT ROYAL...AND ALONG ROUTE 75 OUTSIDE OF TOWN.

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, 2.1 hours before the alert went out and 191 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 2011-09-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 134 joules per kilogram.LCLLFCEL10008507005003002001001 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 00:00Z on 2011-09-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 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
134 J/kg
Mixed-layer CIN
-79 J/kg
Mixed-layer LCL
1385 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
72 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

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

398 
WGUS51 KCTP 100208
FFWCTP
PAC067-087-099-109-100500-
/O.NEW.KCTP.FF.W.0052.110910T0208Z-110910T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1008 PM EDT FRI SEP 9 2011

THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHEASTERN JUNIATA COUNTY...
  NORTHEASTERN MIFFLIN COUNTY...
  EASTERN PERRY COUNTY...
  WESTERN SNYDER COUNTY...

* UNTIL 100 AM EDT...

* AT 956 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  VERY HEAVY RAIN FROM SLOW MOVING THUNDERSTORMS...CENTERED FROM   
  NEAR MCCLURE...SOUTH TO ICKESBURG AND MILLERSTOWN. ADDITIONAL
  RAINFALL AMOUNTS OF 1 TO 2 INCHES ARE LIKELY ACROSS PARTS OF THE   
  WARNED AREA WITHIN THE NEXT FEW HOURS. 
 
* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO MCCLURE... 
  ICKESBURG...MILLERSTOWN...MCALISTERVILLE...NEWPORT...RICHFIELD AND 
  BEAVERTOWN... 

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 4055 7744 4077 7749 4080 7751 4082 7739
      4082 7736 4081 7735 4083 7728 4085 7712
      4053 7698 4052 7699 4047 7695 4031 7728

$$

FORECASTER: LAMBERT

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 9, 8:19 PM EDTFlash Flood WarningCTPBlair, Cambria, Centre, Clearfield, Huntingdon, Juniata and 2 more3 hr
Sep 9, 8:31 PM EDTSpecial Weather StatementCTPJuniata, Mifflin, Perry59 min
Sep 9, 9:32 PM EDTSpecial Weather StatementCTPJuniata, Perry58 min
Sep 9, 10:41 PM EDTRiver Flood WarningCTPBlair, Huntingdon15 hr
Sep 9, 10:41 PM EDTRiver Flood WarningCTPBlair, Huntingdon6 hr
Sep 9, 10:41 PM EDTRiver Flood WarningCTPPerry15 hr
Sep 9, 11:09 PM EDTFlash Flood WarningCTPDauphin, Montour, Northumberland, Schuylkill, Snyder, Union4 hr
Sep 9, 11:42 PM EDTAreal Flood AdvisoryCTPElk78 min
Sep 10, 12:32 AM EDTFlash Flood Warning EmergencyCTPColumbia, Lycoming, Montour, Northumberland, Schuylkill5 hr
Sep 10, 12:57 AM EDTAreal Flood WarningCTPJuniata, Mifflin, Perry, Snyder6 hr
Sep 10, 1:14 AM EDTSpecial Weather StatementCTPWarren46 min
Sep 10, 4:01 AM EDTAreal Flood AdvisoryCTPElk, McKean, Warren3 hr
Sep 10, 6:51 AM EDTAreal Flood AdvisoryCTPCambria, Cameron, Clearfield, Elk, McKean, Warren3 hr
Sep 10, 9:02 AM EDTFlash Flood WarningCTPCambria, Clearfield4 hr
Sep 10, 4:40 PM EDTAreal Flood AdvisoryCTPAdams, Cumberland, Franklin, Huntingdon, Juniata, Mifflin and 2 more3 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.