Alert archive / Pennsylvania / Flash Flood Warnings in 1996

Flash Flood Warning 23, NWS Philadelphia/Mount Holly

April 16, 1996Chester County, Delaware County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Apr 16, 1996, 5:32 AM EDT for Chester County, Delaware County, Pennsylvania. It was in force for 7 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
Apr 16, 1996, 5:32 AM EDT (09:32 UTC)
Expired
Apr 16, 1996, 12:30 PM EDT
In force
7 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 09:32 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, 9.5 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 1996-04-16Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 00:00Z on 1996-04-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 601 square meters per square second.1939587897Sfc1 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
442 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
601 m²/s²
0-3 km storm-relative helicity
944 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 160946 COR
FFWPHL
PAC029-045-161630-

BULLETIN - EAS ACTIVATION REQUESTED
FLOOD WARNING
NATIONAL WEATHER SERVICE PHILADELPHIA/MOUNT HOLLY NJ
532 AM EDT TUE APR 16 1996

THE NATIONAL WEATHER SERVICE IN PHILADELPHIA/MOUNT HOLLY HAS ISSUED A
FLOOD WARNING EFFECTIVE UNTIL 1230 PM EDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...

IN  PENNSYLVANIA

   ...CHESTER COUNTY...DELAWARE COUNTY

THE AUTOMATIC RIVER GAGE AT DOWNINGTOWN ON THE EAST BRANCH OF THE
BRANDYWINE IS CURRENTLY AT 7.4 FEET AND RISING. FLOOD STAGE IS 7 FEET.
THE EAST BRANCH SHOULD RISE TO 8.5 TO 9 FEET AT DOWNINGTOWN. ON THE WEST
BRANCH THE GAGE AT MODENA WAS READING 6 FEET. FLOOD STAGE AT THIS GAGE
IS 9 FEET. DOWN STREAM AT CHADDS FORD THE CREEK WAS AT 4 FEET AND
RISING. IT SHOULD CREST LATE THIS MORNING AT CHADDS FORD AT NEAR 11 FT.
THE FLOOD STAGE IS 9 FEET.

DO NOT ATTEMPT TO DRIVE THROUGH FLOODED AREAS.  THE DEPTH OF THE
WATER MAY BE HIGHER 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
Apr 16, 1:23 AM EDTFlash Flood WarningPHICarbon, Lehigh4 hr
Apr 16, 1:23 AM EDTFlash Flood WarningPHIBerks, Chester4 hr
Apr 16, 3:15 AM EDTFlash Flood WarningPHIMonroe6 hr
Apr 16, 4:15 AM EDTFlash Flood WarningPHIMonroe6 hr
Apr 16, 9:15 AM EDTFlash Flood WarningPHIMonroe6 hr
Apr 16, 1:14 PM EDTFlash Flood WarningPHIBucks3 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.