Alert archive / Pennsylvania / Flash Flood Warnings in 2003

Flash Flood Warning 39, NWS State College, PA

September 23, 2003York County, Pennsylvania

NWS State College, PA issued this flash flood warning at Sep 23, 2003, 3:20 AM EDT for York County, Pennsylvania. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Sep 23, 2003, 3:20 AM EDT (07:20 UTC)
Expired: Sep 23, 2003, 7:15 AM EDT
In force: 4 hr
Issued by: NWS State College, PA
Area: Whole counties

County York County, PA

The radar

The Sterling radar (KLWX), 124 km from the middle of the area, began a volume at 07:21 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

Washington/Dulle, VA (KIAD), launched 00:00Z, 7.3 hours before the alert went out and 122 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: 7 J/kg
Mixed-layer CIN: -42 J/kg
Mixed-layer LCL: 918 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 281 m²/s²
0-3 km storm-relative helicity: 400 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

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

000 
WGUS51 KCTP 230720
FFWCTP
PAC133-231115-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
320 AM EDT TUE SEP 23 2003

THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS ISSUED A

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

* UNTIL 715 AM EDT.

* AT 312 AM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SERIES OF VERY HEAVY SHOWERS AND THUNDERSTORMS CONTINUING OVER 
  YORK COUNTY.

SINCE 10 PM...RADAR ESTIMATES THAT UP TO TWO INCHES OF RAIN HAS 
FALLEN OVER WESTERN AND CENTRAL YORK COUNTY. MINOR FLOODING IS 
ALREADY BEING REPORTED...AND MORE SHOWERS AND THUNDERSTORMS WILL 
PRODUCE RAINFALL OVER THE WARNED AREA THROUGH AT LEAST 5 AM. RUNOFF 
FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING.

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.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODS AND FLASH FLOODS.

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

$$

LAT...LON 4023 7686 3972 7625 3972 7700 3991 7696
          4008 7710

DANGELO

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 23, 2:35 AM EDT	Flash Flood Warning	CTP	Adams	3 hr
Sep 23, 2:38 AM EDT	Flash Flood Warning	CTP	Snyder	3 hr
Sep 23, 3:59 AM EDT	Flash Flood Warning	CTP	Dauphin	3 hr
Sep 23, 4:05 AM EDT	Flash Flood Warning	CTP	Lancaster	3 hr
Sep 23, 5:20 AM EDT	Flash Flood Warning	CTP	Adams, Dauphin, Lancaster, York	4 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2003 Every flash flood warning in 2003

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.