Alert archive / Pennsylvania / Flash Flood Warnings in 2004

Flash Flood Warning 9, NWS State College, PA

May 21, 2004Warren County, Pennsylvania

NWS State College, PA issued this flash flood warning at May 21, 2004, 5:19 AM EDT for Warren County, Pennsylvania. It was in force for 4 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
May 21, 2004, 5:19 AM EDT (09:19 UTC)
Expired
May 21, 2004, 9:15 AM EDT
In force
4 hr
Issued by
NWS State College, PA
Area
Counties, with a storm outline in the text

County Warren County, PA

The radar

The Buffalo radar (KBUF), 128 km from the middle of the area, began a volume at 09:20 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 21, 6:23 AM EDTFLASH FLOODChandlers Valley, PANUMEROUS WATER RESCUES IN SUGAR GROVE. VEHICLES WASHED OFF ROAD RT 957
May 21, 6:50 AM EDTFLASH FLOODSugar Grove, PA

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

The nearest sounding before it

Buffalo Intl Airport, NY (KBUF), launched 00:00Z, 9.3 hours before the alert went out and 127 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, Buffalo Intl Airport, NY at 00:00Z on 2004-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1163 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, Buffalo Intl Airport, NY at 00:00Z on 2004-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 284 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
1163 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
875 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
284 m²/s²
0-3 km storm-relative helicity
339 m²/s²
Significant tornado parameter
2.2
Supercell composite
9.4

Open this sounding in Storm Lab

The text

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

000 
WGUS51 KCTP 210920
FFWCTP
PAC123-211315-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
519 AM EDT FRI MAY 21 2004

THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  WARREN COUNTY IN NORTH CENTRAL PENNSYLVANIA

* UNTIL 915 AM EDT.

* AT 509 AM EDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED           
  THUNDERSTORMS WITH VERY HEAVY RAINFALL.

SLOW MOVING THUNDERSTORMS ARE PRODUCING TORRENTIAL RAINFALL IN THE
WARNED AREA. RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH 
FLOODING IN THE VICINITY OF SUGAR GROVE OF NORTH CENTRAL WARREN 
COUNTY. SOME CREEKS THAT WILL BE IMPACTED ARE LITTLE BROKENSTRAW 
CREEK...STILLWATER CREEK...AND PATCHEN RUN...ESPECIALLY BETWEEN BEAR 
LAKE AND SUGAR GROVE.

ADDITIONAL THUNDERSTORMS MAY PRODUCE UP TO AN ADDITIONAL INCH OF 
RAINFALL THROUGH 7 AM.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED. MOVE TO
HIGHER GROUND.

SMALL CREEKS AND STREAMS WILL RAPIDLY FLOOD...POSSIBLY WASHING OUT
ROADS AND FLOODING NEARBY LOW AREAS.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS
IMMINENT. NEVER ATTEMPT TO CROSS HIGH WATER IN A VEHICLE OR ON FOOT

PLEASE REPORT HAIL...STRONG WINDS OR WIND DAMAGE TO THE NATIONAL
WEATHER SERVICE BY CALLING TOLL FREE...1-877-633-6772.

LAT...LON 4199 7895 4164 7898 4165 7960 4199 7961

$$

KL/BL
1 follow-up statement
000 
WGUS71 KCTP 211052
FFSCTP
PAC123-211245-

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
644 AM EDT FRI MAY 21 2004


...A FLASH FLOOD WARNING CONTINUES FOR WARREN COUNTY UNTIL 915 AM
EDT...

AT 637 AM EDT...LOCAL LAW EMERGENCY MANAGEMENT OFFICIALS AND LAW 
ENFORCEMENT OFFICIALS REPORTED FLOODING...ROAD CLOSURES AND 
EVACUATIONS AROUND THE TOWN OF SUGAR GROVE IN NORTHERN WARREN 
COUNTY. PERIODS OF VERY HEAVY RAINFALL FROM TRAINING THUNDERSTORMS 
ALONG A SLOW MOVING COLD FRONT WILL CONTINUE INTO LATE THIS MORNING.

ADDITIONAL RAINFALL AMOUNTS OF ONE HALF INCH...TO ONE AND ONE HALF 
INCHES DURING THE NEXT 1 TO 2 HOURS WILL CONTINUE...AND POSSIBLY 
INCREASE THE EXTENT OF FLOODING FROM NEAR BEAR LAKE...EAST THROUGH 
SUGAR GROVE...TO RUSSELL AND GERMANY.

SMALL CREEKS AND STREAMS WILL RAPIDLY FLOOD...POSSIBLY WASHING OUT 
ROADS AND FLOODING NEARBY LOW AREAS.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED. MOVE TO
HIGHER GROUND.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS
IMMINENT. NEVER ATTEMPT TO CROSS HIGH WATER IN A VEHICLE OR ON FOOT

CAMPERS IN THE WARNED AREA MUST MOVE TO HIGHER GROUND IMMEDIATELY.

LAT...LON 4201 7962 4192 7958 4185 7897 4200 7898

$$

LAMBERT

The office that day

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

IssuedProductOfficeCountiesLasted
May 20, 10:51 PM EDTSevere Thunderstorm WarningCTPClearfield54 min
May 20, 11:18 PM EDTSevere Thunderstorm WarningCTPWarren72 min
May 20, 11:48 PM EDTFlash Flood WarningCTPClearfield6 hr
May 21, 4:54 AM EDTFlash Flood WarningCTPClearfield4 hr
May 21, 6:29 AM EDTSevere Thunderstorm WarningCTPCambria, Somerset61 min
May 21, 6:31 AM EDTFlash Flood WarningCTPBlair4 hr
May 21, 7:11 AM EDTSevere Thunderstorm WarningCTPBedford, Blair49 min
May 21, 6:55 PM EDTSevere Thunderstorm WarningCTPCambria, Clearfield, Somerset80 min
May 21, 7:30 PM EDTSevere Thunderstorm WarningCTPBedford, Blair60 min

Nearby

Flash Flood Warnings in Pennsylvania, 2004Every flash flood warning in 2004

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.