Alert archive / Pennsylvania / Flash Flood Warnings in 1989

Flash Flood Warning 43, NWS Philadelphia/Mount Holly

October 20, 1989Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Oct 20, 1989, 10:25 AM EDT for Philadelphia County, Pennsylvania. It was in force for 65 min.

The area

The counties it named.

The facts

Issued
Oct 20, 1989, 10:25 AM EDT (14:25 UTC)
Expired
Oct 20, 1989, 11:30 AM EDT
In force
65 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

County Philadelphia County, PA

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Atlantic City In, NJ (KACY), launched 12:00Z, 2.4 hours before the alert went out and 82 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, Atlantic City In, NJ at 12:00Z on 1989-10-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 151 joules per kilogram.LCLLFCEL10008507005003002001001 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, Atlantic City In, NJ at 12:00Z on 1989-10-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 123 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
151 J/kg
Mixed-layer CIN
-48 J/kg
Mixed-layer LCL
526 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
123 m²/s²
0-3 km storm-relative helicity
170 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 201428
FFWPHL
PAC101-201530-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED
URBAN AND SMALL STREAM FLOOD WARNING
NATIONAL WEATHER SERVICE PHILADELPHIA PA
1025 AM EDT FRI OCT 20 1989

THE NATIONAL WEATHER SERVICE HAS ISSUED A URBAN AND SMALL
STREAM FLOOD WARNING EFFECTIVE UNTIL 1130 AM EDT FOR PEOPLE IN
THE FOLLOWING COUNTY

   IN THE SOUTHEAST PART OF PENNSYLVANIA
      PHILADELPHIA

VERY HEAVY RAIN WAS INDICATED BY RADAR OVER PHILADELPHIA COUNTY AT 1025
AM...AND OVER AN INCH OF RAIN HAS FALLEN BETWEEN 930 AND 1030 AM.

IF YOU ARE IN PHILADELPHIA COUNTY IN AN AREA SUBJECT TO FLOODING
MOVE TO HIGHER GROUND. DO NOT DRIVE THROUGH FLOOD WATERS. CLIMBING
ATOP YOUR STALLED VEHICLE WILL NOT PREVENT YOU FROM BEING SWEPT
INTO DANGEROUS STREAM CONDITIONS AS WATER LEVELS RISE.

AN URBAN AND SMALL STREAM FLOOD WATCH REMAINS IN EFFECT FOR PORTIONS OF
EASTERN PENNSYLVANIA AND SOUTHERN NEW JERSEY THROUGH EARLY THIS
AFTERNOON.

WERT

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 20, 3:05 PM EDTFlash Flood WarningPHIBucks3 hr

Nearby

Flash Flood Warnings in Pennsylvania, 1989Every flash flood warning in 1989

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.