Alert archive / Pennsylvania / Tornado Warnings in 1998

Tornado Warning 14, NWS Philadelphia/Mount Holly

September 2, 1998Delaware County, Pennsylvania

NWS Philadelphia/Mount Holly issued this tornado warning at Sep 2, 1998, 7:01 PM EDT for Delaware County, Pennsylvania. It was in force for 34 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
Sep 2, 1998, 7:01 PM EDT (23:01 UTC)
Expired
Sep 2, 1998, 7:35 PM EDT
In force
34 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

County Delaware County, PA

The radar

The Philadelphia radar (KDIX), 84 km from the middle of the area, began a volume at 23:00 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 11.0 hours before the alert went out and 78 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 1998-09-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 1998-09-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 74 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1665 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
74 m²/s²
0-3 km storm-relative helicity
157 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KPHL 022301 RRA
TORPHL
PAC045-022335-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
701 PM EDT WED SEP 2 1998

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* TORNADO WARNING FOR...
  DELAWARE COUNTY IN PENNSYLVANIA

* UNTIL 735 PM EDT

* AT 700 PM EDT... A TORNADO WAS INDICATED 7 MILES WEST OF CHESTER
  HEIGHTS... BY NATIONAL WEATHER SERVICE DOPPLER RADAR... MOVING
  EAST SOUTHEAST 20 MPH.

* THE TORNADO IS EXPECTED TO BE NEAR...
  CHESTER HEIGHTS AT 720 PM EDT

DO NOT TRY TO OUTRUN THIS TORNADO WITH YOUR CAR OR OTHER VEHICLE.
ABANDON CARS OR MOBILE HOMES FOR SHELTER IN A NEARBY REINFORCED
BUILDING. AS A LAST RESORT...GET IN A CULVERT OR DITCH AND COVER
YOUR HEAD WITH YOUR HANDS.

IN A HOME OR BUSINESS...SEEK SHELTER IN A BASEMENT...OR AN
INTERIOR ROOM ON THE LOWEST FLOOR POSSIBLE. STAY AWAY FROM WINDOWS.

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

MD/RPW

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 2, 5:20 PM EDTSevere Thunderstorm WarningPHICarbon35 min
Sep 2, 5:39 PM EDTSevere Thunderstorm WarningPHINorthampton46 min
Sep 2, 6:46 PM EDTTornado WarningPHIChester34 min

Nearby

Tornado Warnings in Pennsylvania, 1998Every tornado warning in 1998Tornadoes 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; radar from the NEXRAD Level II archive.