Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 79, NWS Milwaukee, WI

August 21, 2002Walworth County, Wisconsin

NWS Milwaukee, WI issued this severe thunderstorm warning at Aug 21, 2002, 7:29 PM CDT for Walworth County, Wisconsin. It was in force for 61 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
Aug 21, 2002, 7:29 PM CDT (00:29 UTC)
Expired
Aug 21, 2002, 8:30 PM CDT
In force
61 min
Issued by
NWS Milwaukee, WI
Area
Whole counties

County Walworth County, WI

The radar

The Milwaukee radar (KMKX), 33 km from the middle of the area, began a volume at 00:32 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
Aug 21, 7:40 PM CDTThunderstorm Wind 52 ERichmond, WI
Aug 21, 7:51 PM CDTThunderstorm Wind 56 EElkhorn, WI

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
Aug 21, 2:25 PM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 0.5 hours before the alert went out and 199 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, Davenport, at 00:00Z on 2002-08-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2239 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, Davenport, at 00:00Z on 2002-08-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 288 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
2239 J/kg
Mixed-layer CIN
-23 J/kg
Mixed-layer LCL
997 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
288 m²/s²
0-3 km storm-relative helicity
522 m²/s²
Significant tornado parameter
4.5
Supercell composite
24.4

Open this sounding in Storm Lab

The text

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

099 
WUUS53 KMKX 220029
SVRMKE
WIC127-220130-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
729 PM CDT WED AUG 21 2002

THE NATIONAL WEATHER SERVICE IN SULLIVAN HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WALWORTH COUNTY IN SOUTHEAST WISCONSIN

* UNTIL 830 PM CDT

* AT 729 PM CDT...THE PUBLIC REPORTED SEVERE THUNDERSTORMS WITH
  DAMAGING WINDS LOCATED ALONG A LINE EXTENDING FROM 3 MILES EAST OF
  WHITEWATER TO 3 MILES WEST OF DARIEN...MOVING EAST AT 20 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  DARIEN BY 735 PM CDT.
  DELAVAN LAKE BY 745 PM CDT.
  ELKHORN BY 750 PM CDT.
  WILLIAMS BAY BY 755 PM CDT.

IF YOU ARE IN THE PATH OF THIS LINE OF STORMS...YOU SHOULD PREPARE
FOR DAMAGING WINDS IN EXCESS OF 60 MPH...LARGE HAIL...AND DEADLY
LIGHTNING. SEEK SHELTER IMMEDIATELY

EISE

The office that day

Everything else NWS Milwaukee, WI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 21, 7:16 PM CDTSevere Thunderstorm WarningMKXDane, Jefferson59 min
Aug 21, 7:25 PM CDTSpecial Marine WarningMKX65 min
Aug 21, 7:25 PM CDTSpecial Marine WarningMKX65 min
Aug 21, 7:48 PM CDTSevere Thunderstorm WarningMKXWaukesha27 min
Aug 21, 8:00 PM CDTSevere Thunderstorm WarningMKXKenosha, Racine60 min
Aug 21, 8:01 PM CDTSevere Thunderstorm WarningMKXWashington14 min
Aug 21, 8:08 PM CDTSevere Thunderstorm WarningMKXMilwaukee, Ozaukee67 min
Aug 21, 8:16 PM CDTSpecial Marine WarningMKX89 min
Aug 21, 8:16 PM CDTSpecial Marine WarningMKX89 min
Aug 21, 8:16 PM CDTSpecial Marine WarningMKX89 min
Aug 21, 9:37 PM CDTSevere Thunderstorm WarningMKXGreen, Rock53 min
Aug 22, 4:04 AM CDTFlash Flood WarningMKXLafayette3 hr

Nearby

Severe Thunderstorm Warnings in Wisconsin, 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; radar from the NEXRAD Level II archive.