Alert archive / Pennsylvania / Flash Flood Warnings in 2011

Flash Flood Warning 22, NWS State College, PA

May 18, 2011Dauphin County, Northumberland County, Snyder County, Pennsylvania

NWS State College, PA issued this flash flood warning at May 18, 2011, 6:31 PM EDT for Dauphin County, Northumberland County, Snyder County, 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
May 18, 2011, 6:31 PM EDT (22:31 UTC)
Expired
May 18, 2011, 9:30 PM EDT
In force
3 hr
Issued by
NWS State College, PA
Area
Storm-based polygon
Flood severity
None

Counties Dauphin County, PA, Northumberland County, PA, Snyder County, PA

The radar

The State College radar (KCCX), 103 km from the middle of the area, began a volume at 22:31 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

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 10.5 hours before the alert went out and 140 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, Phillips Aaf/Abe, MD at 12:00Z on 2011-05-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 79 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, Phillips Aaf/Abe, MD at 12:00Z on 2011-05-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 66 square meters per square second.1939587897Sfc1 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
79 J/kg
Mixed-layer CIN
-31 J/kg
Mixed-layer LCL
561 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
66 m²/s²
0-3 km storm-relative helicity
169 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

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

890 
WGUS51 KCTP 182231
FFWCTP
PAC043-097-109-190130-
/O.NEW.KCTP.FF.W.0022.110518T2231Z-110519T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
631 PM EDT WED MAY 18 2011

THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHEASTERN DAUPHIN COUNTY...
  EASTERN SNYDER COUNTY...
  SOUTHWESTERN NORTHUMBERLAND COUNTY...

* UNTIL 930 PM EDT...

* AT 622 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  VERY HEAVY RAIN OVER EASTERN SNYDER...NORTHEASTERN DAUPHIN         
  AND SOUTHWESTERN NORTHUMBERLAND COUNTIES.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO RURAL AREAS
  OF EASTERN SNYDER...NORTHEASTERN DAUPHIN AND SOUTHWESTERN
  NORTHUMBERLAND COUNTIES.

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!

&&

LAT...LON 4063 7695 4064 7694 4065 7696 4079 7713
      4088 7693 4048 7667 4030 7661 4028 7668

$$

FORECASTER: CR

The office that day

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

IssuedProductOfficeCountiesLasted
May 17, 8:17 PM EDTTornado WarningCTPFranklin, Fulton28 min
May 17, 8:45 PM EDTTornado WarningCTPFranklin, Fulton45 min
May 17, 9:30 PM EDTSpecial Weather StatementCTPBedford30 min
May 18, 2:25 AM EDTAreal Flood AdvisoryCTPSomerset3 hr
May 18, 5:13 AM EDTAreal Flood AdvisoryCTPBedford, Somerset3 hr
May 18, 11:51 AM EDTSpecial Weather StatementCTPBedford24 min
May 18, 12:00 PM EDTSpecial Weather StatementCTPFulton30 min
May 18, 12:14 PM EDTSpecial Weather StatementCTPSomerset31 min
May 18, 2:51 PM EDTSpecial Weather StatementCTPYork54 min
May 18, 3:11 PM EDTSevere Thunderstorm WarningCTPYork49 min
May 18, 4:00 PM EDTAreal Flood AdvisoryCTPBedford, Somerset3 hr
May 18, 4:11 PM EDTFlash Flood WarningCTPSomerset3 hr
May 18, 4:20 PM EDTAreal Flood AdvisoryCTPCumberland, Dauphin, York3 hr
May 18, 4:23 PM EDTSpecial Weather StatementCTPJuniata, Perry67 min
May 18, 4:31 PM EDTFlash Flood WarningCTPAdams, Cumberland, Dauphin, Lancaster, Perry, York4 hr
May 18, 4:47 PM EDTSpecial Weather StatementCTPDauphin43 min
May 18, 5:11 PM EDTSevere Thunderstorm WarningCTPFranklin64 min
May 18, 5:20 PM EDTAreal Flood AdvisoryCTPCentre, Juniata, Mifflin, Snyder, Union3 hr
May 18, 5:52 PM EDTFlash Flood WarningCTPCentre, Clearfield, Clinton, Juniata, Mifflin, Snyder and 1 more3 hr
May 18, 6:32 PM EDTSpecial Weather StatementCTPDauphin, Snyder, Union43 min
May 18, 6:52 PM EDTSevere Thunderstorm WarningCTPCentre, Clinton, Lycoming, Snyder, Union38 min
May 18, 7:47 PM EDTAreal Flood AdvisoryCTPCameron, Clearfield, Clinton, Elk, McKean, Potter and 1 more3 hr
May 18, 7:57 PM EDTAreal Flood AdvisoryCTPCentre, Clinton, Lycoming, Snyder, Union3 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.