Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 43, NWS Philadelphia/Mount Holly

May 13, 2002Chester County, Pennsylvania; Cecil County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 13, 2002, 4:40 PM EDT for Chester County, Pennsylvania; Cecil County, Maryland. It was in force for 65 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
May 13, 2002, 4:40 PM EDT (20:40 UTC)
Expired
May 13, 2002, 5:45 PM EDT
In force
65 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

Counties Cecil County, MD, Chester County, PA

What was reported inside it

TimeReportWhereRemark
May 13, 4:45 PM EDTThunderstorm Wind 50 ERising Sun, MD

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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
May 13, 1:30 PM EDTTornado WatchSPC6 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 8.7 hours before the alert went out and 161 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 2002-05-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 313 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 2002-05-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 117 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
313 J/kg
Mixed-layer CIN
-110 J/kg
Mixed-layer LCL
1186 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
117 m²/s²
0-3 km storm-relative helicity
127 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.0

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 132040
SVRPHI
MDC015-PAC029-132145-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
440 PM EDT MON MAY 13 2002

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN CECIL COUNTY IN NORTHEAST MARYLAND.
  CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA.

* UNTIL 545 PM EDT.

* AT 438 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM... ALONG A LINE EXTENDING FROM 4 MILES WEST OF
  HONEY BROOK TO 10 MILES SOUTHWEST OF RISING SUN...MOVING EAST AT 20
  MPH. 

* SEVERE THUNDERSTORMS WILL BE NEAR...
  HONEY BROOK AT 450 PM.
  PARKESBURG...RISING SUN AT 455 PM.
  ELVERSON...OXFORD AT 500 PM.
  COATESVILLE AT 505 PM.
  WEST GROVE...NORTH EAST AT 515 PM.
  DOWNINGTOWN AT 520 PM.

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

$$

The office that day

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

IssuedProductOfficeCountiesLasted
May 13, 2:18 PM EDTSevere Thunderstorm WarningPHIBerks42 min
May 13, 2:41 PM EDTSevere Thunderstorm WarningPHIMontgomery34 min
May 13, 3:02 PM EDTSevere Thunderstorm WarningPHIBerks28 min
May 13, 3:08 PM EDTTornado WarningPHIBerks37 min
May 13, 3:08 PM EDTTornado WarningPHIBerks112 min
May 13, 3:21 PM EDTSevere Thunderstorm WarningPHIMontgomery24 min
May 13, 3:25 PM EDTFlash Flood WarningPHIBerks95 min
May 13, 4:57 PM EDTFlash Flood WarningPHIBerks2 hr
May 13, 5:03 PM EDTSevere Thunderstorm WarningPHIMontgomery42 min
May 13, 5:16 PM EDTSevere Thunderstorm WarningPHIBucks39 min
May 12, 8:07 PM EDTSevere Thunderstorm WarningPHICaroline, Kent, Queen Anne's38 min
May 13, 4:02 PM EDTTornado WarningPHICecil, Kent43 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2002Severe Thunderstorm Warnings in Maryland, 2002Every severe thunderstorm warning 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.