Alert archive / Delaware / Flash Flood Warnings in 1998

Flash Flood Warning 6, NWS Philadelphia/Mount Holly

March 21, 1998New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Mar 21, 1998, 4:10 AM EST for New Castle County, Delaware. It was in force for 6 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
Mar 21, 1998, 4:10 AM EST (09:10 UTC)
Expired
Mar 21, 1998, 10:00 AM EST
In force
6 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

County New Castle County, DE

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 9.2 hours before the alert went out and 167 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, Washington/Dulle, VA at 00:00Z on 1998-03-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 00:00Z on 1998-03-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 255 square meters per square second.193958Sfc1 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
2 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
448 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
255 m²/s²
0-3 km storm-relative helicity
420 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KPHL 210915
FFWPHL
DEC003-211500-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
410 AM EST SAT MAR 21 1998

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL 1000 AM EST
FOR PEOPLE IN THE FOLLOWING LOCATION...

IN DELAWARE

   ...NEW CASTLE COUNTY...CHRISTINA RIVER

AT 410 AM THE STAGE OF THE CHRISTINA RIVER AT COOCHS BRIDGE WAS 8.75
FEET AND RISING.  FLOOD STAGE AT COOCHS BRIDGE IS 9 FT. A CREST OF 
AROUND 10.5 FEET IS EXPECTED AT COOCHS BRIDGE BY 10 AM THIS MORNING.

HEAVY RAIN OVER NORTHERN DELAWARE OVERNIGHT IS PRODUCING RAPID
RISES ALONG STREAMS IN THIS AREA. NATIONAL WEATHER SERVICE DOPPLER 
RADAR INDICATES THAT THE CURRENT SHOT OF HEAVY RAIN WILL TAPER OFF
OVER THE NEXT HOUR. THE CHRISTINA RIVER AT COOCHS BRIDGE IS EXPECTED 
TO RISE ABOVE ITS 9 FOOT FLOOD STAGE BY AROUND 600 AM AND CREST 
BEFORE 10 AM.

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.

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

NPC

Nearby

Flash Flood Warnings in Delaware, 1998Every flash flood warning in 1998

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.