Alert archive / Pennsylvania / Flash Flood Warnings in 2011

Flash Flood Warning 19, NWS State College, PA

May 18, 2011Somerset County, Pennsylvania

NWS State College, PA issued this flash flood warning at May 18, 2011, 4:11 PM EDT for Somerset 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
May 18, 2011, 4:11 PM EDT (20:11 UTC)
Expired
May 18, 2011, 7:15 PM EDT
In force
3 hr
Issued by
NWS State College, PA
Area
Storm-based polygon
Flood severity
None

County Somerset County, PA

The radar

The Pittsburgh radar (KPBZ), 112 km from the middle of the area, began a volume at 20:14 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
May 18, 4:55 PM EDTFLASH FLOODMeyersdale, PALOCALIZED FLOODING AND ROAD CLOSURES

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

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 12:00Z, 8.2 hours before the alert went out and 96 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, Pittsburgh, PA at 12:00Z on 2011-05-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Pittsburgh, PA at 12:00Z on 2011-05-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -49 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
777 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
-49 m²/s²
0-3 km storm-relative helicity
-19 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

019 
WGUS51 KCTP 182011
FFWCTP
PAC111-182315-
/O.NEW.KCTP.FF.W.0019.110518T2011Z-110518T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOMERSET COUNTY...

* UNTIL 715 PM EDT...

* AT 407 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM OVER SOMERSET COUNTY.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO 
ROCKWOOD...GARRETT...MEYERSDALE...AND BERLIN.

ADDITIONAL RAINFALL AMOUNTS OF UP TO AN INCH AND A HALF ARE POSSIBLE 
IN THE WARNED AREA. THIS RAINFALL IS EXPECTED TO CREATE FLASH 
FLOODING AND PERHAPS MUDSLIDES AS WELL. 

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 3972 7939 3973 7941 3982 7937 3985 7942
      3990 7941 4009 7926 4012 7921 4012 7919
      4016 7917 3990 7875 3982 7875 3972 7881

$$

FORECASTER: DANGELO
1 follow-up statement
532 
WGUS71 KCTP 182244
FFSCTP

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
644 PM EDT WED MAY 18 2011

PAC111-182315-
/O.CON.KCTP.FF.W.0019.000000T0000Z-110518T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SOMERSET PA-
644 PM EDT WED MAY 18 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 715 PM EDT FOR
SOMERSET COUNTY...

AT 636 PM EDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED A
THUNDERSTORM PRODUCING FLASH FLOODING OVER SOMERSET COUNTY.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO BERLIN...
FRIEDENS...MEYERSDALE...MOUNT DAVIS AND SOMERSET.

THE RAIN IS TAPERING OFF AT THIS TIME...AND ONLY A FEW TENTHS OF AN 
INCH OF ADDITIONAL RAINFALL ARE POSSIBLE IN THE WARNED AREA. THIS 
SHOULD ALLOW THE FLOOD WATERS TO RECEDE SHORTLY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT 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. 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 7939 3973 7941 3982 7937 3985 7942
      3990 7941 4009 7926 4012 7921 4012 7919
      4016 7917 3990 7875 3982 7875 3972 7881

$$

FORECASTER: DANGELO

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, 4:20 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, 6:31 PM EDTFlash Flood WarningCTPDauphin, Northumberland, Snyder3 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.