Alert archive / Wisconsin / Tornado Watches in 2002

Tornado Watch 110

April 18, 200247 counties in Wisconsin

The Storm Prediction Center issued this tornado watch at Apr 18, 2002, 2:30 PM CDT for 47 counties in Wisconsin. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Apr 18, 2002, 2:30 PM CDT (19:30 UTC)
Expired
Apr 18, 2002, 8:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
All 47 counties

Adams County, WI, Calumet County, WI, Chippewa County, WI, Clark County, WI, Columbia County, WI, Crawford County, WI, Dane County, WI, Dodge County, WI, Eau Claire County, WI, Fond du Lac County, WI, Grant County, WI, Green County, WI, Green Lake County, WI, Iowa County, WI, Jackson County, WI, Jefferson County, WI, Juneau County, WI, Kenosha County, WI, La Crosse County, WI, Lafayette County, WI, Langlade County, WI, Lincoln County, WI, Marathon County, WI, Marquette County, WI, Menominee County, WI, Milwaukee County, WI, Monroe County, WI, Oconto County, WI, Outagamie County, WI, Ozaukee County, WI, Portage County, WI, Racine County, WI, Richland County, WI, Rock County, WI, Rusk County, WI, Sauk County, WI, Shawano County, WI, Taylor County, WI, Trempealeau County, WI, Vernon County, WI, Walworth County, WI, Washington County, WI, Waukesha County, WI, Waupaca County, WI, Waushara County, WI, Winnebago County, WI, Wood County, WI

The radar

The Green Bay radar (KGRB), 100 km from the middle of the area, began a volume at 19:31 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

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

IssuedProductOfficeCountiesLasted
Apr 18, 2:48 PM CDTSevere Thunderstorm WarningMKXIowa, Lafayette, Sauk57 min
Apr 18, 2:57 PM CDTTornado WarningARXGrant63 min
Apr 18, 2:59 PM CDTSevere Thunderstorm WarningARXRichland46 min
Apr 18, 3:07 PM CDTTornado WarningMKXLafayette23 min
Apr 18, 3:29 PM CDTTornado WarningMKXLafayette31 min
Apr 18, 3:31 PM CDTTornado WarningMKXLafayette29 min
Apr 18, 3:44 PM CDTSevere Thunderstorm WarningMKXColumbia, Dane, Iowa, Sauk61 min
Apr 18, 3:48 PM CDTSevere Thunderstorm WarningARXAdams, Juneau57 min
Apr 18, 3:53 PM CDTSevere Thunderstorm WarningGRBLincoln, Oneida37 min
Apr 18, 3:57 PM CDTTornado WarningMKXGreen, Lafayette33 min
Apr 18, 4:03 PM CDTTornado WarningMKXColumbia, Sauk27 min
Apr 18, 4:12 PM CDTSevere Thunderstorm WarningMPXChippewa63 min
Apr 18, 4:20 PM CDTSevere Thunderstorm WarningMPXEau Claire, Pepin40 min
Apr 18, 4:21 PM CDTSevere Thunderstorm WarningARXTaylor54 min
Apr 18, 4:29 PM CDTSevere Thunderstorm WarningGRBLincoln, Oneida46 min
Apr 18, 4:31 PM CDTTornado WarningMKXColumbia, Sauk29 min
Apr 18, 4:34 PM CDTTornado WarningGRBLincoln, Oneida41 min
Apr 18, 4:45 PM CDTSevere Thunderstorm WarningMKXGreen, Rock60 min
Apr 18, 4:56 PM CDTSevere Thunderstorm WarningARXJuneau, Vernon49 min
Apr 18, 4:56 PM CDTTornado WarningMKXRock49 min
Apr 18, 4:57 PM CDTSevere Thunderstorm WarningMPXEau Claire63 min
Apr 18, 4:59 PM CDTSevere Thunderstorm WarningMKXMarquette31 min
Apr 18, 5:03 PM CDTSevere Thunderstorm WarningARXTaylor42 min
Apr 18, 5:07 PM CDTSevere Thunderstorm WarningGRBWaushara, Winnebago53 min
Apr 18, 5:14 PM CDTSevere Thunderstorm WarningARXMonroe46 min
Apr 18, 5:16 PM CDTSevere Thunderstorm WarningGRBLincoln, Oneida59 min
Apr 18, 5:25 PM CDTSevere Thunderstorm WarningARXClark65 min
Apr 18, 5:30 PM CDTSevere Thunderstorm WarningMKXJefferson, Rock, Walworth60 min
Apr 18, 5:32 PM CDTSevere Thunderstorm WarningMKXDane43 min
Apr 18, 5:33 PM CDTSevere Thunderstorm WarningGRBMarathon57 min
Apr 18, 5:34 PM CDTSevere Thunderstorm WarningMPXRusk26 min
Apr 18, 5:44 PM CDTSevere Thunderstorm WarningARXTaylor61 min
Apr 18, 5:47 PM CDTSevere Thunderstorm WarningARXAdams, Juneau58 min
Apr 18, 5:57 PM CDTSevere Thunderstorm WarningMPXEau Claire63 min
Apr 18, 6:04 PM CDTSevere Thunderstorm WarningARXTrempealeau56 min
Apr 18, 6:10 PM CDTSevere Thunderstorm WarningMKXDane, Jefferson35 min
Apr 18, 6:17 PM CDTSevere Thunderstorm WarningARXLa Crosse88 min
Apr 18, 6:22 PM CDTSevere Thunderstorm WarningARXClark53 min
Apr 18, 6:30 PM CDTSevere Thunderstorm WarningGRBMarathon, Wood60 min
Apr 18, 6:34 PM CDTSevere Thunderstorm WarningARXJackson, Monroe56 min
Apr 18, 6:42 PM CDTSevere Thunderstorm WarningARXJuneau78 min
Apr 18, 6:45 PM CDTSevere Thunderstorm WarningARXCrawford60 min
Apr 18, 6:59 PM CDTSevere Thunderstorm WarningMPXChippewa31 min
Apr 18, 7:18 PM CDTSevere Thunderstorm WarningMKXKenosha42 min
Apr 18, 7:21 PM CDTSevere Thunderstorm WarningMKXDane, Jefferson39 min
Apr 18, 7:26 PM CDTSevere Thunderstorm WarningGRBLincoln, Oneida49 min
Apr 18, 7:26 PM CDTTornado WarningGRBMarathon34 min
Apr 18, 7:28 PM CDTSevere Thunderstorm WarningMKXRock62 min
Apr 18, 7:40 PM CDTSevere Thunderstorm WarningARXGrant, Richland95 min
Apr 18, 7:42 PM CDTSevere Thunderstorm WarningGRBPortage, Shawano63 min
Apr 18, 7:49 PM CDTSevere Thunderstorm WarningARXCrawford56 min
Apr 18, 7:50 PM CDTSevere Thunderstorm WarningGRBLanglade, Menominee55 min
Apr 18, 7:59 PM CDTSevere Thunderstorm WarningMKXSauk61 min

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 7.5 hours before the alert went out and 100 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 2002-04-18Temperature 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°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 2002-04-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 460 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
1774 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
460 m²/s²
0-3 km storm-relative helicity
766 m²/s²
Significant tornado parameter
0.0
Supercell composite
4.1

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 181918
SEL0  
SPC WW 181914
WIZ000-LMZ000-190100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 110
STORM PREDICTION CENTER NORMAN OK
214 PM CDT THU APR 18 2002

THE STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

   WISCONSIN                          
   LAKE MICHIGAN                      

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 230 PM UNTIL 800
PM CDT.

TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 85 STATUTE MILES EAST AND WEST
OF A LINE FROM 50 MILES NORTH NORTHWEST OF WAUSAU WISCONSIN TO 15
MILES SOUTHWEST OF JANESVILLE WISCONSIN.

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. 
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.


DISCUSSION...VERY UNSTABLE AIR MASS ACROSS SRN WI WITH WARM FRONT
MOVING NWD THRU CENTRAL PORTION OF STATE.  SHEAR PROFILES ARE VERY
FAVORABLE FOR ORGANZIED SEVERE THUNDERSTORMS AND ISOLATED TORNADIC
SUPERCELLS.


AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 70 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 600. 
MEAN STORM MOTION VECTOR 24035.


...HALES

422,0905 453,0914 453,0881 422,0873

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 18, 1:00 AM CDTSevere Thunderstorm WatchSPCBarron, Buffalo, Chippewa, Crawford, Dunn, Eau Claire and 10 more6 hr
Apr 18, 4:15 PM CDTTornado WatchSPCLa Crosse, Monroe5 hr
Apr 18, 5:00 PM CDTTornado WatchSPCFlorence, Forest, Oneida, Vilas5 hr

Nearby

Tornado Watches in Wisconsin, 2002Every tornado watch 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.