Alert archive / Iowa / Tornado Watches in 2002

Tornado Watch 113

April 18, 200244 counties in Iowa; 5 counties in Minnesota; La Crosse County, Monroe County, Wisconsin

The Storm Prediction Center issued this tornado watch at Apr 18, 2002, 4:15 PM CDT for 44 counties in Iowa; 5 counties in Minnesota; La Crosse County, Monroe County, Wisconsin. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Apr 18, 2002, 4:15 PM CDT (21:15 UTC)
Expired
Apr 18, 2002, 9:00 PM CDT
In force
5 hr
Issued by
the Storm Prediction Center
All 51 counties

Adair County, IA, Adams County, IA, Allamakee County, IA, Audubon County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Butler County, IA, Cass County, IA, Cerro Gordo County, IA, Chickasaw County, IA, Clarke County, IA, Dallas County, IA, Decatur County, IA, Fayette County, IA, Floyd County, IA, Franklin County, IA, Fremont County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hardin County, IA, Howard County, IA, Jasper County, IA, Lucas County, IA, Madison County, IA, Marion County, IA, Marshall County, IA, Mills County, IA, Mitchell County, IA, Montgomery County, IA, Page County, IA, Polk County, IA, Ringgold County, IA, Story County, IA, Tama County, IA, Taylor County, IA, Union County, IA, Warren County, IA, Webster County, IA, Winneshiek County, IA, Worth County, IA, Wright County, IA, Fillmore County, MN, Houston County, MN, Mower County, MN, Olmsted County, MN, Winona County, MN, La Crosse County, WI, Monroe County, WI

The radar

The Des Moines radar (KDMX), 39 km from the middle of the area, began a volume at 21:20 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

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

IssuedProductOfficeCountiesLasted
Apr 18, 4:29 PM CDTSevere Thunderstorm WarningARXMower61 min
Apr 18, 4:30 PM CDTSevere Thunderstorm WarningARXMower60 min
Apr 18, 4:31 PM CDTSevere Thunderstorm WarningARXFloyd44 min
Apr 18, 4:43 PM CDTSevere Thunderstorm WarningARXOlmsted77 min
Apr 18, 4:51 PM CDTSevere Thunderstorm WarningOAXPage24 min
Apr 18, 4:57 PM CDTSevere Thunderstorm WarningARXChickasaw63 min
Apr 18, 5:00 PM CDTSevere Thunderstorm WarningDMXAdams45 min
Apr 18, 5:02 PM CDTSevere Thunderstorm WarningOAXMontgomery18 min
Apr 18, 5:07 PM CDTSevere Thunderstorm WarningDMXGuthrie38 min
Apr 18, 5:10 PM CDTSevere Thunderstorm WarningDMXHamilton35 min
Apr 18, 5:14 PM CDTSevere Thunderstorm WarningARXMonroe46 min
Apr 18, 5:15 PM CDTSevere Thunderstorm WarningARXWabasha, Winona60 min
Apr 18, 5:22 PM CDTSevere Thunderstorm WarningDMXDallas53 min
Apr 18, 5:23 PM CDTSevere Thunderstorm WarningDMXHardin37 min
Apr 18, 5:25 PM CDTTornado WarningARXChickasaw50 min
Apr 18, 5:27 PM CDTSevere Thunderstorm WarningDMXBoone33 min
Apr 18, 5:30 PM CDTSevere Thunderstorm WarningARXFillmore60 min
Apr 18, 5:34 PM CDTSevere Thunderstorm WarningDMXGreene26 min
Apr 18, 5:41 PM CDTSevere Thunderstorm WarningDMXStory34 min
Apr 18, 5:47 PM CDTSevere Thunderstorm WarningDMXBoone43 min
Apr 18, 5:49 PM CDTSevere Thunderstorm WarningARXFayette, Winneshiek56 min
Apr 18, 5:53 PM CDTTornado WarningARXHoward, Winneshiek67 min
Apr 18, 5:53 PM CDTSevere Thunderstorm WarningDMXTaylor52 min
Apr 18, 6:00 PM CDTSevere Thunderstorm WarningDMXPolk60 min
Apr 18, 6:04 PM CDTTornado WarningDMXGrundy, Hardin56 min
Apr 18, 6:06 PM CDTSevere Thunderstorm WarningDMXGuthrie, Madison24 min
Apr 18, 6:14 PM CDTTornado WarningDMXDallas61 min
Apr 18, 6:17 PM CDTSevere Thunderstorm WarningARXHouston, Winona88 min
Apr 18, 6:18 PM CDTSevere Thunderstorm WarningDMXStory42 min
Apr 18, 6:31 PM CDTSevere Thunderstorm WarningARXAllamakee59 min
Apr 18, 6:34 PM CDTSevere Thunderstorm WarningARXChickasaw41 min
Apr 18, 6:34 PM CDTSevere Thunderstorm WarningARXJackson, Monroe56 min
Apr 18, 6:40 PM CDTSevere Thunderstorm WarningDMXRinggold50 min
Apr 18, 6:45 PM CDTSevere Thunderstorm WarningDMXPolk60 min
Apr 18, 6:49 PM CDTSevere Thunderstorm WarningARXWinneshiek56 min
Apr 18, 6:52 PM CDTTornado WarningDMXPolk23 min
Apr 18, 6:55 PM CDTSevere Thunderstorm WarningDMXMadison, Warren65 min
Apr 18, 7:02 PM CDTSevere Thunderstorm WarningDMXJasper58 min
Apr 18, 7:04 PM CDTSevere Thunderstorm WarningDMXMarshall26 min
Apr 18, 7:04 PM CDTTornado WarningDMXJasper56 min
Apr 18, 7:10 PM CDTSevere Thunderstorm WarningARXFayette65 min
Apr 18, 7:10 PM CDTTornado WarningDMXBlack Hawk50 min
Apr 18, 7:24 PM CDTTornado WarningDMXDecatur, Ringgold51 min
Apr 18, 7:34 PM CDTSevere Thunderstorm WarningARXAllamakee, Clayton56 min
Apr 18, 7:38 PM CDTSevere Thunderstorm WarningDMXJasper, Marion52 min
Apr 18, 7:57 PM CDTSevere Thunderstorm WarningDMXWarren33 min

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 9.3 hours before the alert went out and 237 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, Omaha, NE at 12:00Z on 2002-04-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2266 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, Omaha, NE at 12:00Z on 2002-04-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 396 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
2266 J/kg
Mixed-layer CIN
-161 J/kg
Mixed-layer LCL
1005 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
396 m²/s²
0-3 km storm-relative helicity
481 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.3

Open this sounding in Storm Lab

The text

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

000
WWUS20 KWNS 182054
SEL3

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 18, 1:00 AM CDTSevere Thunderstorm WatchSPCAllamakee, Black Hawk, Bremer, Buchanan, Buena Vista, Butler and 29 more6 hr
Apr 18, 3:00 PM CDTTornado WatchSPCCedar, Clinton, Delaware, Dubuque, Jackson, Jones and 3 more5 hr
Apr 18, 2:30 PM CDTTornado WatchSPCAdams, Calumet, Chippewa, Clark, Columbia, Crawford and 41 more6 hr
Apr 18, 5:00 PM CDTTornado WatchSPCFlorence, Forest, Oneida, Vilas5 hr

Nearby

Tornado Watches in Iowa, 2002Tornado Watches in Minnesota, 2002Tornado 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.