Alert archive / Pennsylvania / Flash Flood Warnings in 1990
Flash Flood Warning 10, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 27, 1990, 6:34 PM EDT for Montgomery County, Philadelphia County, Pennsylvania. It was in force for 116 min.
The area
The counties it named.
The facts
- Issued
- Aug 27, 1990, 6:34 PM EDT (22:34 UTC)
- Expired
- Aug 27, 1990, 8:30 PM EDT
- In force
- 116 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Whole counties
Counties Montgomery County, PA, 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, 10.6 hours before the alert went out and 97 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
- 244 J/kg
- Mixed-layer CIN
- -42 J/kg
- Mixed-layer LCL
- 1003 m above ground
- 0-6 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- 24 m²/s²
- 0-3 km storm-relative helicity
- 72 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 272237 FFWPHL NJC005-PAC091-101-280030- BULLETIN - EBS ACTIVATION REQUESTED SEVERE THUNDERSTORM AND FLASH FLOOD WARNING NATIONAL WEATHER SERVICE PHILADELPHIA PA 634 PM EDT MON AUG 27 1990 THE NATIONAL WEATHER SERVICE IN PHILADELPHIA HAS ISSUED A SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 730 PM EDT AND A FLASH FLOOD WARNING EFFECTIVE UNTIL 830 PM EDT FOR PEOPLE IN THE FOLLOWING LOCATIONS... IN SOUTH NEW JERSEY ...WESTERN BURLINGTON COUNTY IN SOUTHEAST PENNSYLVANIA ...MONTGOMERY COUNTY...NORTHERN PHILADELPHIA COUNTY AT 625 PM WEATHER SERVICE RADAR SHOWED SEVERE THUNDERSTORMS NEAR THE MONTGOMERY AND BUCKS COUNTY LINES EXTENDING SOUTHEAST INTO WESTERN BURLINGTON COUNTY. THESE THUNDERSTORMS WERE MOVING TO THE SOUTHEAST AAROUND 25 MILES AN HOUR. THIS IS A DANGEROUS STORM. IF YOU ARE IN THE WARNED AREA...PREPARE FOR STRONG DAMAGING WINDS...LARGE HAIL...VERY HEAVY RAIN AND DEADLY LIGHTNING. SHOULD THE STORM APPROACH YOU...SEEK IMMEDIATE SHELTER INDOORS...BUT DO NOT STAND NEAR WINDOWS. MOBILE HOMES ARE MOST VULNERABLE TO HIGH WINDS AND SHOULD BE AVOIDED. HEAVY RAINS WITH THIS THUNDERSTORM MAY CAUSE FLOODING OF SMALL STREAMS AND UNDERPASSES VERY QUICKLY. DwO NOT DRIVE YOUR CAR INTO AREAS WHERE THE WATER COVERS THE ROADWAY. THE WATER MAY BE DEEPER THAN YOU THINK. IF CAUGHT IN RISING WATERS...ABANDON YOUR CAR QUICKLY. MOVE TO HIGHER GROUND. JWH
The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 27, 6:00 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 45 min |
| Aug 27, 6:34 PM EDT | Severe Thunderstorm Warning | PHI | Montgomery, Philadelphia | 116 min |
Nearby
Flash Flood Warnings in Pennsylvania, 1990Every flash flood warning in 1990
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.