Alert archive / Delaware / Flash Flood Warnings in 1998

Flash Flood Warning 1, NWS Philadelphia/Mount Holly

February 23, 1998New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Feb 23, 1998, 7:30 PM EST for New Castle County, Delaware. 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 counties it named.

The facts

Issued
Feb 23, 1998, 7:30 PM EST (00:30 UTC)
Expired
Feb 23, 1998, 10:30 PM EST
In force
3 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, 0.5 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 1998-02-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 1998-02-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 262 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
471 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
262 m²/s²
0-3 km storm-relative helicity
739 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 240032
FFWPHL
DEC003-240330-

BULLETIN - EAS ACTIVATION REQUESTED
FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
730 PM EST MON FEB 23 1998

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
FLOOD WARNING EFFECTIVE UNTIL 1030 PM EST
FOR PEOPLE IN THE FOLLOWING LOCATION...

IN DELAWARE

   ...NORTHERN NEW CASTLE COUNTY

HEAVY RAIN...ESPECIALLY IN THE HEADWATERS OF THE CHRISTINA RIVER
HAVE CAUSED THE RIVER AT COOCH/S BRIDGE TO REACH A STAGE OF 8.5
FEET AS OF 725 PM.  THE RIVER HAS RISEN A FOOT IN THE LAST 30
MINUTES AND SHOULD REACH ITS FLOOD STAGE OF 9 FEET AROUND 8 PM.
THE HEAVY RAIN HAS MOVED OUT OF THE AREA AND THE RIVER SHOULD CREST
BETWEEN 9 AND 9.5 FEET THIS EVENING.

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

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

TFG

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 23, 10:15 PM ESTFlash Flood WarningPHINew Castle105 min

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.