Alert archive / Iowa / Severe Thunderstorm Watches in 2002

Severe Thunderstorm Watch 618

August 17, 200243 counties in Iowa; 11 counties in Minnesota; 25 counties in Nebraska

The Storm Prediction Center issued this severe thunderstorm watch at Aug 17, 2002, 1:05 AM CDT for 43 counties in Iowa; 11 counties in Minnesota; 25 counties in Nebraska. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Aug 17, 2002, 1:05 AM CDT (06:05 UTC)
Expired
Aug 17, 2002, 6:00 AM CDT
In force
5 hr
Issued by
the Storm Prediction Center
All 79 counties

Adair County, IA, Audubon County, IA, Boone County, IA, Buena Vista County, IA, Butler County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Cerro Gordo County, IA, Cherokee County, IA, Chickasaw County, IA, Clay County, IA, Crawford County, IA, Dallas County, IA, Emmet County, IA, Floyd County, IA, Franklin County, IA, Fremont County, IA, Greene County, IA, Guthrie County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Harrison County, IA, Howard County, IA, Humboldt County, IA, Ida County, IA, Kossuth County, IA, Mills County, IA, Mitchell County, IA, Monona County, IA, Montgomery County, IA, Page County, IA, Palo Alto County, IA, Pocahontas County, IA, Pottawattamie County, IA, Sac County, IA, Shelby County, IA, Webster County, IA, Winnebago County, IA, Woodbury County, IA, Worth County, IA, Wright County, IA, Dodge County, MN, Faribault County, MN, Fillmore County, MN, Freeborn County, MN, Houston County, MN, Martin County, MN, Mower County, MN, Olmsted County, MN, Steele County, MN, Waseca County, MN, Winona County, MN, Burt County, NE, Butler County, NE, Cass County, NE, Clay County, NE, Colfax County, NE, Dodge County, NE, Douglas County, NE, Fillmore County, NE, Gage County, NE, Jefferson County, NE, Johnson County, NE, Lancaster County, NE, Nemaha County, NE, Nuckolls County, NE, Otoe County, NE, Pawnee County, NE, Polk County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Thayer County, NE, Washington County, NE, Webster County, NE, York County, NE

The radar

The Omaha radar (KOAX), 63 km from the middle of the area, began a volume at 06:07 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

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

IssuedProductOfficeCountiesLasted
Aug 17, 1:06 AM CDTSevere Thunderstorm WarningFSDWoodbury39 min
Aug 17, 1:08 AM CDTSevere Thunderstorm WarningFSDCherokee37 min
Aug 17, 1:15 AM CDTSevere Thunderstorm WarningFSDClay, O'Brien45 min
Aug 17, 1:35 AM CDTSevere Thunderstorm WarningFSDBuena Vista40 min
Aug 17, 1:39 AM CDTSevere Thunderstorm WarningFSDIda, Woodbury36 min
Aug 17, 1:42 AM CDTSevere Thunderstorm WarningOAXColfax, Dodge48 min
Aug 17, 1:44 AM CDTSevere Thunderstorm WarningDMXPalo Alto46 min
Aug 17, 1:45 AM CDTSevere Thunderstorm WarningFSDCherokee30 min
Aug 17, 1:53 AM CDTSevere Thunderstorm WarningOAXBurt22 min
Aug 17, 2:15 AM CDTSevere Thunderstorm WarningFSDIda45 min
Aug 17, 2:24 AM CDTSevere Thunderstorm WarningDMXSac51 min
Aug 17, 2:55 AM CDTSevere Thunderstorm WarningOAXCass, Lancaster, Otoe, Sarpy35 min
Aug 17, 3:03 AM CDTSevere Thunderstorm WarningOAXGage, Jefferson, Saline42 min
Aug 17, 3:05 AM CDTSevere Thunderstorm WarningDMXCalhoun40 min
Aug 17, 3:13 AM CDTSevere Thunderstorm WarningDMXWebster47 min
Aug 17, 3:13 AM CDTSevere Thunderstorm WarningOAXJohnson, Pawnee32 min
Aug 17, 3:27 AM CDTSevere Thunderstorm WarningOAXNemaha, Richardson33 min
Aug 17, 3:33 AM CDTSevere Thunderstorm WarningDMXHamilton, Wright57 min
Aug 17, 3:38 AM CDTSevere Thunderstorm WarningDMXBoone37 min
Aug 17, 3:45 AM CDTSevere Thunderstorm WarningDMXGreene30 min
Aug 17, 3:49 AM CDTSevere Thunderstorm WarningDMXAdair, Adams56 min
Aug 17, 3:51 AM CDTSevere Thunderstorm WarningOAXGage, Jefferson, Johnson, Pawnee24 min
Aug 17, 3:58 AM CDTSevere Thunderstorm WarningDMXFranklin, Hardin42 min

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 6.1 hours before the alert went out and 63 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 00:00Z on 2002-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3070 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 00:00Z on 2002-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 229 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
3070 J/kg
Mixed-layer CIN
-50 J/kg
Mixed-layer LCL
1356 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
229 m²/s²
0-3 km storm-relative helicity
597 m²/s²
Significant tornado parameter
3.9
Supercell composite
18.4

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 17, 3:45 AM CDTSevere Thunderstorm WatchSPCAdams, Allamakee, Appanoose, Benton, Black Hawk, Bremer and 37 more5 hr
Aug 16, 10:00 PM CDTSevere Thunderstorm WatchSPCAnoka, Becker, Benton, Big Stone, Carver, Chippewa and 39 more5 hr
Aug 16, 11:20 PM CDTSevere Thunderstorm WatchSPCAdams, Antelope, Boone, Buffalo, Cedar, Colfax and 36 more6 hr

Nearby

Severe Thunderstorm Watches in Iowa, 2002Severe Thunderstorm Watches in Nebraska, 2002Severe Thunderstorm Watches in Minnesota, 2002Every severe thunderstorm 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.