Alert archive / Pennsylvania / Flash Flood Warnings in 2004

Flash Flood Warning 4, NWS Philadelphia/Mount Holly

June 17, 2004Chester County, Pennsylvania; New Castle County, Delaware; Sussex County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Jun 17, 2004, 8:20 PM EDT for Chester County, Pennsylvania; New Castle County, Delaware; Sussex County, New Jersey. It was in force for 93 days. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jun 17, 2004, 8:20 PM EDT (00:20 UTC)
Expired: Sep 18, 2004, 10:00 AM EDT
In force: 93 days
Issued by: NWS Philadelphia/Mount Holly
Area: Counties, with a storm outline in the text

Counties New Castle County, DE, Sussex County, NJ, Chester County, PA

The radar

The Philadelphia radar (KDIX), 134 km from the middle of the area, began a volume at 00:23 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.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 0.3 hours before the alert went out and 161 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: 108 J/kg
Mixed-layer CIN: -168 J/kg
Mixed-layer LCL: 1087 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 85 m²/s²
0-3 km storm-relative helicity: 80 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 KPHI 180025
FFWPHI
DEC003-PAC029-180415-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
820 PM EDT THU JUN 17 2004

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHERN NEW CASTLE COUNTY IN NORTHERN DELAWARE
  THIS INCLUDES THE CITY OF...NEWARK
  SOUTHERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA

* UNTIL 1215 AM EDT

* AT 813 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A CLUSTER OF THUNDERSTORMS WITH TORRENTIAL DOWNPOURS WAS ENTERING
  SOUTHWEST CHESTER COUNTY. THIS CLUSTER WILL BE MOVING OVER AREAS
  THAT HAVE HAD HEAVIER RAIN EARLIER TODAY AND EARLIER THIS WEEK AND 
  ARE VERY VULNERABLE TO ADDITIONAL HEAVY RAIN. THE CLUSTER OF STORMS
  PRODUCED UP TO TWO INCHES OF RAIN IN THE PAST HOUR IN LANCASTER
  COUNTY. 

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WEST
  GROVE...OXFORD...KENNETT SQUARE...COATESVILLE...WILMINGTON MANOR...
  TALLEYVILLE...STANTON...NEWPORT...NEW CASTLE AND ELSMERE.


THE MOST VULNERABLE CREEKS ARE THE RED CLAY AND WHITE CLAY IN BOTH 
CHESTER AND NEW CASTLE COUNTIES AND THE CHRISTINA RIVER IN NEW 
CASTLE COUNTY.  

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS
SUBJECT TO FLOODING WHEN WATER BEGINS RISING. 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.

FOR THE LATEST STORM INFORMATION...PLEASE TUNE TO NOAA WEATHER
RADIO...YOUR LOCAL RADIO OR TELEVISION STATION...OR YOUR CABLE
TELEVISION OUTLET.

LAT...LON 4006 7588 3979 7551 3969 7553 3963 7561
          3958 7558 3959 7579 3973 7579 3973 7597
          3979 7606

$$

GIGI

1 follow-up statement

000 
WGUS51 KPHI 181049
FFWPHI
NJC037-181400-
/X.NEW.KPHI.FF.W.0004.040918T1046Z-040918T1400Z/
/0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
646 AM EDT SAT SEP 18 2004

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SUSSEX COUNTY IN NORTHWEST NEW JERSEY

* UNTIL 1000 AM EDT

* AT 645 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
FLASH FLOODING FROM PERSISTENT HEAVY RAIN AND THUNDERSTORMS OVER 
SUSSEX COUNTY. RADAR HAS ESTIMATED BETWEEN 2 AND 3 INCHES OF RAIN IN 
THE PAST FEW HOURS THROUGHOUT THE COUNTY...WITH MORE RAIN ON THE 
WAY. 

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL 
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED QUICKLY.
MOVE TO HIGHER GROUND.

LAT...LON 4109 7494 4092 7472 4118 7445 4133 7473

$$

JJM

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 17, 8:12 PM EDT	Severe Thunderstorm Warning	PHI	Chester	33 min
Jun 17, 8:45 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	30 min
Jun 17, 9:02 PM EDT	Severe Thunderstorm Warning	PHI	Salem	43 min

Nearby

Flash Flood Warnings in Pennsylvania, 2004 Flash Flood Warnings in Delaware, 2004 Flash Flood Warnings in New Jersey, 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.