Alert archive / Pennsylvania / Flash Flood Warnings in 1996

Flash Flood Warning 122, NWS Philadelphia/Mount Holly

December 2, 1996Chester County, Delaware County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Dec 2, 1996, 4:12 AM EST for Chester County, Delaware County, Pennsylvania. 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
Dec 2, 1996, 4:12 AM EST (09:12 UTC)
Expired
Dec 2, 1996, 8:10 AM EST
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

Counties Chester County, PA, Delaware County, PA

The radar

The Philadelphia radar (KDIX), 99 km from the middle of the area, began a volume at 09:13 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, 9.2 hours before the alert went out and 192 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 1996-12-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 16 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 00:00Z on 1996-12-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 322 square meters per square second.1939587897117Sfc1 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
16 J/kg
Mixed-layer CIN
-83 J/kg
Mixed-layer LCL
458 m above ground
0-6 km bulk shear
75 kt
0-1 km storm-relative helicity
322 m²/s²
0-3 km storm-relative helicity
347 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 020912
FFWPHL
PAC017-029-045-021310-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PHILADELPHIA/MOUNT HOLLY NJ
412 AM EST MON DEC 2 1996

THE NATIONAL WEATHER SERVICE IN PHILADELPHIA/MOUNT HOLLY NJ HAS
ISSUED A FLASH FLOOD WARNING EFFECTIVE UNTIL 810 AM EST
FOR PEOPLE IN THE FOLLOWING LOCATION...

IN  PENNSYLVANIA

   ...CHESTER COUNTY
   ...BUCKS COUNTY
   ...DELAWARE COUNTY
 
AT 4 AM SMALL STREAMS WERE NEARING THEIR BANKS AND SHOULD BEGIN
FLOODING SHORTLY. IN THE WARNED COUNTIES FLOODING IS EXPECTED ALONG
THE BRANDYWINE...NESHAMINY AND CHESTER CREEKS AS WELL AS SMALL
STREAMS AND CREEKS THROUGHOUT THE COUNTIES.

A FLASH FLOOD WATCH REMAINS IN EFFECT FOR THE AREA.

STAY TUNED TO NOAA WEATHER RADIO...THE VOICE OF THE NATIONAL WEATHER
SERVICE...OR TO COMMERCIAL RADIO OR TELEVISION STATIONS FOR THE
LATEST STORM INFORMATION.
 
IF YOU ARE IN AN AREA PRONE TO FLOODING...MOVE TO HIGHER GROUND
IMMEDIATELY...BEFORE YOUR ACCESS IS CUT OFF BY RISING FLOOD WATERS.
IF YOUR VEHICLE STALLS...ABANDON IT AND SEEK HIGHER GROUND QUICKLY.
RAPIDLY RISING WATER MAY ENGULF THE CAR AND SWEEP IT AWAY.

DO NOT ATTEMPT TO DRIVE THROUGH FLOODED AREAS. THE WATER MAY BE
DEEPER THAN YOU THINK. RAPIDLY RISING WATERS CAN QUICKLY ENGULF
YOUR VEHICLE AND ITS OCCUPANTS...WASHING THEM AWAY. REMEMBER...
MOST FLASH FLOOD DEATHS OCCUR IN AUTOMOBILES.

WN

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 2, 3:05 AM ESTFlash Flood WarningPHICarbon, Monroe4 hr
Dec 2, 4:12 AM ESTFlash Flood WarningPHIBucks4 hr
Dec 2, 8:15 AM ESTFlash Flood WarningPHIChester5 hr

Nearby

Flash Flood Warnings in Pennsylvania, 1996Every flash flood warning in 1996

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.