Alert archive / Pennsylvania / Flash Flood Warnings in 1989
Flash Flood Warning 41, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 20, 1989, 6:30 PM EDT for Bucks County, Montgomery County, Pennsylvania. It was in force for 3 hr.
The area
The counties it named.
The facts
- Issued
- Sep 20, 1989, 6:30 PM EDT (22:30 UTC)
- Expired
- Sep 20, 1989, 9:00 PM EDT
- In force
- 3 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Whole counties
Counties Bucks County, PA, Montgomery 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, 10.5 hours before the alert went out and 111 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.
- Mixed-layer CAPE
- 441 J/kg
- Mixed-layer CIN
- -3 J/kg
- Mixed-layer LCL
- 545 m above ground
- 0-6 km bulk shear
- 13 kt
- 0-1 km storm-relative helicity
- 36 m²/s²
- 0-3 km storm-relative helicity
- 49 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000
TTAA00 KPHL 202240
FFWPHL
PAC017-091-210100-
BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED
URBAN AND SMALL STREAM FLOOD WARNING
NATIONAL WEATHER SERVICE PHILADELPHIA PA
630 PM EDT WED SEP 20 1989
THE NATIONAL WEATHER SERVICE HAS EXTENDED AN URBAN AND SMALL STREAM
FLOOD WARNING UNTIL 900 PM EDT FOR PEOPLE IN THE FOLLOWING
COUNTIES
IN THE SOUTHEAST PART OF PENNSYLVANIA
EASTERN BUCKS...EASTERN MONTGOMERY
URBAN AND SMALL STREAM FLOODING CONTINUES OVER MUCH OF THE EASTERN
PORTIONS OF BUCKS AND MONTGOMERY COUNTIES IN SOUTHEASTERN PENNSYLVANIA.
THE AUTOMATIC STREAM GAUGE ON THE NESHAMINY CREEK AT LANGHORNE REPORTED
A LEVEL OF 10.49 FEET SHORTLY AFTER 600 PM. THE FLOOD STAGE OF THE
NESHAMINY CREEK AT LANGHORNE IN 9.00 FEET. ANOTHER AUTOMATIC STREAM
GAUGE LOCATED ON THE PERKIOMEN CREEK AT GRATERFORD INDICATED A LEVEL OF
11.01 FEET. THE FLOOD STAGE OF THE PERKIOMEN CREEK AT GRATERFORD IS
11.00 FEET.
WEATHER SERVICE RADAR AT 630 PM INDICATED AN AREA OF SHOWERS WITH
HEAVY RAIN OVER EASTERN SECTIONS OF CHESTER COUNTY...EXTENDING EAST
INTO DELAWARE COUNTY. THIS AREA OF PRECIPITATION WAS MOVING NORTHEAST
AT 25 MILES AN HOUR. GROUND CONDITIONS REMAIN SATURATED FROM HEAVY
RAINFALL EARLIER TODAY...AND ANY ADDITIONAL HEAVY PRECIPITATION WILL
CAUSE SMALL STREAM AND CREEK LEVELS TO FURTHER RISE...AND CONTINUE
URBAN FLOODING PROBLEMS THROUGH THIS EVENING.
IF YOU LIVE IN THE WARNED COUNTIES AND ARE IN AN AREA SUBJECT TO
FLOODING...PLEASE MOVE TO HIGHER GROUND IMMEDIATELY. 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 WARNING CONTINUES IN EFFECT UNTIL 900 PM
FOR MERCER COUNTY IN CENTRAL NEW JERSEY. A FLOOD WARNING REMAINS IN
EFFECT FOR TONIGHT FOR THE RANCOCAS CREEK IN BURLINGTON COUNTY OF NEW
JERSEY.
DAWThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 20, 7:42 AM EDT | Flash Flood Warning | PHI | Montgomery | 3 hr |
| Sep 20, 8:14 AM EDT | Flash Flood Warning | PHI | Bucks | 3 hr |
| Sep 20, 2:33 PM EDT | Flash Flood Warning | PHI | Bucks, Montgomery | 3 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.