Alert archive / Pennsylvania / Flash Flood Warnings in 2004

Flash Flood Warning 2, NWS State College, PA

May 9, 2004York County, Pennsylvania

NWS State College, PA issued this flash flood warning at May 9, 2004, 9:20 PM EDT for York 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 9, 2004, 9:20 PM EDT (01:20 UTC)
Expired: May 10, 2004, 12:15 AM EDT
In force: 3 hr
Issued by: NWS State College, PA
Area: Counties, with a storm outline in the text

County York County, PA

The radar

The Sterling radar (KLWX), 129 km from the middle of the area, began a volume at 01:23 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

Time	Report	Where	Remark
May 9, 10:30 PM EDT	FLASH FLOOD	York, PA	NUMEROUS ROADS AND BASEMENTS FLOODED

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

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 1.3 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-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: 629 J/kg
Mixed-layer CIN: -20 J/kg
Mixed-layer LCL: 1932 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 43 m²/s²
0-3 km storm-relative helicity: 151 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.9

Open this sounding in Storm Lab

The text

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

000 
WGUS51 KCTP 100129
FFWCTP
PAC133-100415-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
920 PM EDT SUN MAY 9 2004

THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS ISSUED A

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

* UNTIL 1215 AM EDT.

* AT 920 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS CENTRAL AND SOUTHERN 
  YORK COUNTY.

SLOW MOVING THUNDERSTORMS ARE PRODUCING TORRENTIAL RAINFALL IN THE 
WARNED AREA. RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH 
FLOODING...ESPECIALLY IN THE AREA FROM NEAR YORK TO RED LION...AND 
BROGUE WHERE THE HEAVIEST RAIN WAS OCCURRING FROM SEVERAL...TRAINING 
THUNDERSTORMS.

RADAR ESTIMATED THAT RAINFALL OF 2 TO 3 INCHES OCCURRED NEAR RED 
LION OVER THE PAST 3 HOURS...WITH AN ADDITIONAL INCH POSSIBLE OVER 
THE NEXT HOUR OR TWO.

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.

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...MOVE TO HIGHER GROUND IMMEDIATELY.

LAT...LON 3981 7630 3991 7640 3991 7643 3995 7656
          4000 7670 4003 7686 4005 7703 3991 7696
          3977 7649 3974 7626

$$

LAMBERT/GARTNER/CRUZ

The office that day

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

Issued	Product	Office	Counties	Lasted
May 10, 12:09 AM EDT	Flash Flood Warning	CTP	York	3 hr
May 10, 5:31 PM EDT	Severe Thunderstorm Warning	CTP	Warren	59 min
May 10, 6:54 PM EDT	Severe Thunderstorm Warning	CTP	McKean	66 min
May 10, 7:04 PM EDT	Severe Thunderstorm Warning	CTP	Elk	56 min
May 10, 7:38 PM EDT	Severe Thunderstorm Warning	CTP	Warren	37 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.