Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 32, NWS Philadelphia/Mount Holly

May 25, 1998Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 25, 1998, 8:23 AM EDT for Montgomery County, Pennsylvania. It was in force for 47 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
May 25, 1998, 8:23 AM EDT (12:23 UTC)
Expired
May 25, 1998, 9:10 AM EDT
In force
47 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

County Montgomery County, PA

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 0.4 hours before the alert went out and 224 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, Washington/Dulle, VA at 12:00Z on 1998-05-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 34 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, Washington/Dulle, VA at 12:00Z on 1998-05-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 217 square meters per square second.19395878Sfc1 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
34 J/kg
Mixed-layer CIN
-260 J/kg
Mixed-layer LCL
559 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
217 m²/s²
0-3 km storm-relative helicity
230 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

476 
WUUS1 KPHL 251225 RRA
SVRPHL
PAC091-251310-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
823 AM EDT MON MAY 25 1998

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  MONTGOMERY COUNTY IN PENNSYLVANIA

* UNTIL 910 AM EDT

* AT 820 AM EDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A SEVERE THUNDERSTORM 3 MILES NORTH NORTHWEST OF GILBERTSVILLE
  MOVING EAST SOUTHEAST AT 45 MPH.

* THE SEVERE THUNDERSTORM IS EXPECTED TO BE NEAR...
  OBELISK AT 814 AM EDT
  LIMERICK AT 816 AM EDT
  SCHWENKSVILLE AT 818 AM EDT
  GRATERFORD AT 820 AM EDT
  COLLEGEVILLE AT 821 AM EDT
  LANSDALE AT 829 AM EDT
  NORRISTOWN AT 832 AM EDT
  CONSHOHOCKEN AT 835 AM EDT
  AMBLER AT 837 AM EDT
  FORT WASHINGTON AT 838 AM EDT
  FLOURTOWN AT 839 AM EDT

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.

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

FRANKLIN/RNS

The office that day

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

IssuedProductOfficeCountiesLasted
May 25, 7:32 AM EDTSevere Thunderstorm WarningPHIBerks63 min
May 25, 8:46 AM EDTSevere Thunderstorm WarningPHIBucks64 min
May 25, 9:05 AM EDTSevere Thunderstorm WarningPHIMontgomery, Philadelphia50 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; the sounding from the Mesonet's radiosonde archive.