Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1989
Severe Thunderstorm Warning 41, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Nov 16, 1989, 10:32 AM EST for Montgomery County, Pennsylvania. It was in force for 58 min. 3 reports came from inside the area while it was in force.
The area
The counties it named, with what was reported inside it.
The facts
- Issued
- Nov 16, 1989, 10:32 AM EST (15:32 UTC)
- Expired
- Nov 16, 1989, 11:30 AM EST
- In force
- 58 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Whole counties
County Montgomery County, PA
The radar
The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Nov 16, 11:00 AM EST | Tornado F0 | Montgomery, PA | |
| Nov 16, 11:10 AM EST | Thunderstorm Wind 0 | Montgomery, PA | |
| Nov 16, 11:10 AM EST | Thunderstorm Wind 0 | Montgomery, PA |
NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.
The nearest sounding before it
Atlantic City In, NJ (KACY), launched 12:00Z, 3.5 hours before the alert went out and 112 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
- 195 J/kg
- Mixed-layer CIN
- -52 J/kg
- Mixed-layer LCL
- 575 m above ground
- 0-6 km bulk shear
- 52 kt
- 0-1 km storm-relative helicity
- 380 m²/s²
- 0-3 km storm-relative helicity
- 388 m²/s²
- Significant tornado parameter
- 0.4
- Supercell composite
- 4.2
The text
As transmitted, in the capitals the NWS used until 2016.
000
TTAA00 KPHL 161535
SVRPHL
PAC091-161630-
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHILADELPHIA PA
1032 AM EST THU NOV 16 1989
THE NATIONAL WEATHER SERVICE IN PHILADELPHIA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1130 AM EST
FOR PEOPLE IN THE FOLLOWING COUNTY...
IN SOUTHEAST PENNSYLVANIA
...MONTGOMERY
AT 1030 AM...WEATHER SERVICE RADAR SHOWED A LINE OF SEVERE
THUNDERSTORMS FROM JUST EAST OF READING IN BERKS COUNTY OF
PENNSYLVANIA TO JUST WEST OF WILMINGTON DELAWARE. WIND GUSTS
REPORTED BEFORE 10 AM WITH THIS LINE WERE 76 MILES AN HOUR
IN LANCASTER CITY AND 64 MILES AN HOUR IN BALTIMORE MARYLAND.
A TORNADO WATCH CONTINUES FOR SOUTHEASTERN
PENNSYLVANIA AND SOUTHERN NEW JERSEY UNTIL 300 PM EDT. REMEMBER
SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES WITH
LITTLE OR NO ADVANCED WARNING.
WITH LEAVES DOWN ALONG THE STREET AND STORM SEWERS CLOGGED...
HEAVY RAINS WITH THIS THUNDERSTORM MAY CAUSE FLOODING OF
STEETS AND UNDERPASSES VERY QUICKLY. DO 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.
JWHThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 16, 10:04 AM EST | Severe Thunderstorm Warning | PHI | Chester | 56 min |
| Nov 16, 10:44 AM EST | Severe Thunderstorm Warning | PHI | Delaware | 61 min |
| Nov 16, 10:49 AM EST | Severe Thunderstorm Warning | PHI | Bucks | 56 min |
| Nov 16, 10:54 AM EST | Severe Thunderstorm Warning | PHI | Philadelphia | 66 min |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 1989Every severe thunderstorm 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.