Alert archive / Pennsylvania / Tornado Warnings in 2002

Tornado Warning 11, NWS Philadelphia/Mount Holly

June 6, 2002Chester County, Delaware County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this tornado warning at Jun 6, 2002, 7:47 PM EDT for Chester County, Delaware County, Montgomery County, Pennsylvania. It was in force for 28 min. 2 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
Jun 6, 2002, 7:47 PM EDT (23:47 UTC)
Expired
Jun 6, 2002, 8:15 PM EDT
In force
28 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

Counties Chester County, PA, Delaware County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 94 km from the middle of the area, began a volume at 23:51 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.

What was reported inside it

TimeReportWhereRemark
Jun 6, 7:50 PM EDTThunderstorm Wind 50 EBroomall, PA
Jun 6, 7:50 PM EDTThunderstorm Wind 50 ENorristown, 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, 11.8 hours before the alert went out and 81 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 2002-06-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 326 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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 2002-06-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 11 square meters per square second.193958Sfc1 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
326 J/kg
Mixed-layer CIN
-110 J/kg
Mixed-layer LCL
1175 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
11 m²/s²
0-3 km storm-relative helicity
89 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.6

Open this sounding in Storm Lab

The text

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

000 
WFUS51 KPHI 062347
TORPHI
PAC029-045-091-070015-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
747 PM EDT THU JUN 6 2002

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHERN DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA
  EAST CENTRAL CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA
  SOUTHEASTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA

* UNTIL 815 PM EDT.

* AT 746 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM WITH STRONG ROTATION OVER PAOLI...MOVING
  NORTHEAST AT 20 MPH. THIS STORM COULD PRODUCE A TORNADO AT ANY
  TIME.

* THE TORNADO IS EXPECTED TO BE NEAR...
  RADNOR TOWNSHIP...DREXEL HILL AT 755 PM.
  BRYN MAWR AT 800 PM.
  KING OF PRUSSIA AT 805 PM.
  NORRISTOWN AT 810 PM.
  PLYMOUTH MEETING...AMBLER AT 815 PM.

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

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM THURSDAY
EVENING FOR SOUTHWESTERN DELAWARE AND NORTHEASTERN MARYLAND AND
SOUTHERN NEW JERSEY.

$$

LAT...LON 4005 7572 3987 7567 3994 7530 4020 7519

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 6, 6:55 PM EDTSevere Thunderstorm WarningPHIChester50 min
Jun 6, 7:36 PM EDTSevere Thunderstorm WarningPHIDelaware39 min

Nearby

Tornado Warnings in Pennsylvania, 2002Every tornado warning in 2002Tornadoes in 2002

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; radar from the NEXRAD Level II archive.