Alert archive / Delaware / Flash Flood Warnings in 1999

Flash Flood Warning 33, NWS Philadelphia/Mount Holly

September 16, 1999New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 16, 1999, 7:28 AM EDT for New Castle County, Delaware. 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 16, 1999, 7:28 AM EDT (11:28 UTC)
Expired
Sep 16, 1999, 11:30 AM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

County New Castle County, DE

The radar

The Dover AFB radar (KDOX), 85 km from the middle of the area, began a volume at 11:28 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, 11.5 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 1999-09-16Temperature 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 1999-09-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 129 square meters per square second.19395878Sfc1 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
536 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
129 m²/s²
0-3 km storm-relative helicity
140 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 161128
FFWPHL
DEC003-161530-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
728 AM EDT THU SEP 16 1999

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NEW CASTLE COUNTY IN DELAWARE.

* UNTIL 1130 AM EDT.

* AT 715 AM EDT OBSERVER REPORTS AND RADAR INDICATED HEAVY RAINS
CONTINUE TO FALL THROUGHOUT NEW CASTLE COUNTY.

* THE AUTOMATIC RIVER GAGE AT COOCHS BRIDGE IS RISING RAPIDLY
AND IS CURRENTLY AT 8 FEET. FLOOD STAGE IS 9 FEET. THIS SHOUD
BE REACHED WITHIN THE NEXT HOUR.

  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.

  .END
  WN

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 16, 9:25 AM EDTFlash Flood WarningPHIKent6 hr
Sep 16, 9:25 AM EDTFlash Flood WarningPHISussex6 hr
Sep 16, 11:25 AM EDTFlash Flood WarningPHINew Castle6 hr
Sep 16, 2:41 PM EDTFlash Flood WarningPHINew Castle6 hr
Sep 16, 3:12 PM EDTFlash Flood WarningPHIKent, Sussex3 hr
Sep 16, 6:13 PM EDTFlash Flood WarningPHIKent3 hr
Sep 16, 6:13 PM EDTFlash Flood WarningPHISussex3 hr

Nearby

Flash Flood Warnings in Delaware, 1999Every flash flood warning in 1999

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.