Alert archive / Wisconsin / Severe Thunderstorm Watches in 2004

Severe Thunderstorm Watch 237

May 21, 200425 counties in Wisconsin

The Storm Prediction Center issued this severe thunderstorm watch at May 21, 2004, 3:00 PM CDT for 25 counties in Wisconsin. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
May 21, 2004, 3:00 PM CDT (20:00 UTC)
Expired
May 21, 2004, 10:00 PM CDT
In force
7 hr
Issued by
the Storm Prediction Center
All 25 counties

Adams County, WI, Calumet County, WI, Columbia County, WI, Dane County, WI, Dodge County, WI, Fond du Lac County, WI, Green County, WI, Green Lake County, WI, Iowa County, WI, Jefferson County, WI, Juneau County, WI, Kenosha County, WI, Lafayette County, WI, Marquette County, WI, Milwaukee County, WI, Ozaukee County, WI, Racine County, WI, Rock County, WI, Sauk County, WI, Sheboygan County, WI, Walworth County, WI, Washington County, WI, Waukesha County, WI, Waushara County, WI, Winnebago County, WI

The radar

The Milwaukee radar (KMKX), 89 km from the middle of the area, began a volume at 20:01 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.

Warnings issued inside it

3 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
May 21, 3:16 PM CDTSevere Thunderstorm WarningMKXSauk29 min
May 21, 3:41 PM CDTSevere Thunderstorm WarningMKXColumbia, Dane49 min
May 21, 6:17 PM CDTFlash Flood WarningMKXKenosha, Racine, Walworth4 hr

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 8.0 hours before the alert went out and 133 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, Green Bay/Straub, WI at 12:00Z on 2004-05-21Temperature 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, Green Bay/Straub, WI at 12:00Z on 2004-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 82 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
1440 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
82 m²/s²
0-3 km storm-relative helicity
196 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 20, 7:32 PM CDTMesoscale DiscussionSPCKenosha88 min
May 21, 4:34 AM CDTMesoscale DiscussionSPCAdams, Buffalo, Columbia, Crawford, Dane, Grant and 15 more56 min
May 21, 9:40 AM CDTMesoscale DiscussionSPCKenosha2 hr
May 21, 9:44 AM CDTMesoscale DiscussionSPCAdams, Buffalo, Crawford, Eau Claire, Grant, Jackson and 9 more3 hr
May 21, 10:25 AM CDTSevere Thunderstorm WatchSPCAdams, Buffalo, Columbia, Crawford, Dane, Dodge and 21 more6 hr
May 21, 1:59 PM CDTMesoscale DiscussionSPCAdams, Columbia, Crawford, Dane, Dodge, Fond du Lac and 10 more2 hr
May 21, 2:45 PM CDTTornado WatchSPCCrawford, Grant, Richland7 hr
May 21, 5:35 PM CDTTornado WatchSPCLafayette5 hr

Nearby

Severe Thunderstorm Watches in Wisconsin, 2004Every severe thunderstorm watch in 2004

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.