Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 129, NWS Philadelphia/Mount Holly

August 18, 1998Berks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 18, 1998, 1:55 PM EDT for Berks County, Pennsylvania. It was in force for 45 min. 1 report 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
Aug 18, 1998, 1:55 PM EDT (17:55 UTC)
Expired
Aug 18, 1998, 2:40 PM EDT
In force
45 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

County Berks County, PA

What was reported inside it

TimeReportWhereRemark
Aug 18, 2:39 PM EDTThunderstorm Wind 50Morgantown, 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.

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 5.9 hours before the alert went out and 106 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, Phillips Aaf/Abe, MD at 12:00Z on 1998-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 148 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, Phillips Aaf/Abe, MD at 12:00Z on 1998-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 3 square meters per square second.1939Sfc1 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
148 J/kg
Mixed-layer CIN
-86 J/kg
Mixed-layer LCL
1092 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
3 m²/s²
0-3 km storm-relative helicity
16 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.

962 
WUUS1 KPHL 181756 RRA
SVRPHL
PAC011-181840-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
155 PM EDT TUE AUG 18 1998

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN BERKS COUNTY IN PENNSYLVANIA

* UNTIL 240 PM EDT

* AT 150 PM EDT RADAR SHOWED TWO THUNDERSTORMS OVER EASTERN
  LEBANON AND NORTHEASTERN LANCASTER COUNTY.  THUNDERSTORMS
  ARE EXPECTED TO MERGE AND INTENSIFY IN THE VICINITY OF
  READING AIRPORT AND WILL LIKELY BECOME SEVERE.

* THE THUNDERSTORM SHOULD BE NEAR THE READING AIRPORT AROUND 215 PM.

THIS IS A DANGEROUS STORM. MOVE INSIDE A STRONG BUILDING AND DO
NOT STAND NEAR WINDOWS. FOR YOUR PROTECTION MOVE TO AN INTERIOR
ROOM ON THE LOWEST FLOOR OF YOUR HOME OR BUSINESS.

DO NOT DRIVE YOUR CAR WHERE WATER COVERS THE ROADWAY. THE WATER
MAY BE DEEPER THAN YOU THINK. IF CAUGHT IN RISING FLOOD WATERS...
ABANDON YOUR CAR QUICKLY AND MOVE TO HIGHER GROUND.

FOR THE LATEST STORM INFORMATION...PLEASE TUNE TO NOAA WEATHER
RADIO...YOUR LOCAL RADIO OR TELEVISION STATIONS...OR YOUR CABLE
TELEVISION OUTLET.

JAE/TFG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 18, 3:58 PM EDTSevere Thunderstorm WarningPHIMontgomery, Philadelphia47 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 1998Every severe thunderstorm warning in 1998

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.