Alert archive / Pennsylvania / Flash Flood Warnings in 2004

Flash Flood Warning 4, NWS State College, PA

May 18, 2004Somerset County, Pennsylvania

NWS State College, PA issued this flash flood warning at May 18, 2004, 4:52 PM EDT for Somerset 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, 2004, 4:52 PM EDT (20:52 UTC)
Expired: May 18, 2004, 7:45 PM EDT
In force: 3 hr
Issued by: NWS State College, PA
Area: Counties, with a storm outline in the text

County Somerset County, PA

The radar

The Pittsburgh radar (KPBZ), 107 km from the middle of the area, began a volume at 20:55 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

Pittsburgh, PA (KPIT), launched 12:00Z, 8.9 hours before the alert went out and 91 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 312 J/kg
Mixed-layer CIN: -25 J/kg
Mixed-layer LCL: 635 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 254 m²/s²
0-3 km storm-relative helicity: 254 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.8

Open this sounding in Storm Lab

The text

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

000 
WGUS51 KCTP 182102
FFWCTP
PAC111-182345-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
452 PM EDT TUE MAY 18 2004

THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOMERSET COUNTY IN SOUTH CENTRAL PENNSYLVANIA

* UNTIL 745 PM EDT.

* AT 441 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A 
LINE OF THUNDERSTORMS PRODUCING VERY HEAVY RAINFALL OVER CENTRAL 
SOMERSET COUNTY.

SLOW MOVING THUNDERSTORMS ARE PRODUCING TORRENTIAL RAINFALL IN THE
WARNED AREA. RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH 
FLOODING IN CENTRAL AND SOUTHERN PORTIONS OF SOMERSET COUNTY... 
ESPECIALLY FROM THE CITY OF SOMERSET SOUTHWARD TO CONFLUENCE AND 
EASTWARD TO MEYERSDALE.

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.

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

LAT...LON 4027 7880 3976 8021 3926 7992 3976 7879

$$

DEVOIR

The office that day

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

Issued	Product	Office	Counties	Lasted
May 17, 11:54 PM EDT	Severe Thunderstorm Warning	CTP	Clearfield	66 min
May 18, 2:16 PM EDT	Severe Thunderstorm Warning	CTP	Warren	59 min
May 18, 5:02 PM EDT	Severe Thunderstorm Warning	CTP	Perry	28 min
May 18, 5:26 PM EDT	Severe Thunderstorm Warning	CTP	Franklin	64 min
May 18, 6:23 PM EDT	Severe Thunderstorm Warning	CTP	Cumberland	67 min
May 18, 6:53 PM EDT	Severe Thunderstorm Warning	CTP	Franklin	37 min
May 18, 7:04 PM EDT	Severe Thunderstorm Warning	CTP	Adams, York	56 min
May 18, 7:31 PM EDT	Flash Flood Warning	CTP	Clearfield	119 min

Nearby

Flash Flood Warnings in Pennsylvania, 2004 Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.