Alert archive / Iowa / Severe Thunderstorm Watches in 2004

Severe Thunderstorm Watch 451

June 12, 20044 counties in Illinois; 39 counties in Iowa

The Storm Prediction Center issued this severe thunderstorm watch at Jun 12, 2004, 3:45 PM CDT for 4 counties in Illinois; 39 counties in Iowa. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Jun 12, 2004, 3:45 PM CDT (20:45 UTC)
Expired
Jun 12, 2004, 9:00 PM CDT
In force
5 hr
Issued by
the Storm Prediction Center
All 43 counties

Appanoose County, IA, Benton County, IA, Boone County, IA, Cedar County, IA, Clarke County, IA, Clinton County, IA, Dallas County, IA, Davis County, IA, Decatur County, IA, Des Moines County, IA, Hamilton County, IA, Henry County, IA, Iowa County, IA, Jackson County, IA, Jasper County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Lee County, IA, Linn County, IA, Louisa County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Monroe County, IA, Muscatine County, IA, Polk County, IA, Poweshiek County, IA, Scott County, IA, Story County, IA, Tama County, IA, Van Buren County, IA, Wapello County, IA, Warren County, IA, Washington County, IA, Wayne County, IA, Henderson County, IL, Mercer County, IL, Rock Island County, IL, Warren County, IL

The radar

The Des Moines radar (KDMX), 97 km from the middle of the area, began a volume at 20:46 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

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

IssuedProductOfficeCountiesLasted
Jun 12, 3:46 PM CDTSevere Thunderstorm WarningDMXPolk, Story44 min
Jun 12, 4:19 PM CDTSevere Thunderstorm WarningDMXHamilton41 min
Jun 12, 4:27 PM CDTSevere Thunderstorm WarningDMXJasper, Marshall48 min
Jun 12, 5:01 PM CDTSevere Thunderstorm WarningDMXMahaska, Poweshiek44 min
Jun 12, 5:10 PM CDTSevere Thunderstorm WarningDVNBenton, Iowa65 min

Discussions around it

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

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 8.8 hours before the alert went out and 320 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 2004-06-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 232 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 2004-06-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 13 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
232 J/kg
Mixed-layer CIN
-305 J/kg
Mixed-layer LCL
2084 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
13 m²/s²
0-3 km storm-relative helicity
18 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 11, 9:35 PM CDTSevere Thunderstorm WatchSPCHenderson, Mercer4 hr
Jun 11, 10:04 PM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, DeKalb, Grundy, Jo Daviess and 10 more56 min
Jun 11, 11:00 PM CDTTornado WatchSPCBureau, Carroll, DeKalb, DuPage, Ford, Grundy and 15 more5 hr
Jun 12, 1:48 AM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, Cook, DeKalb, DuPage and 19 more87 min
Jun 12, 3:08 AM CDTMesoscale DiscussionSPCCook, DeKalb, DuPage, Grundy, Iroquois, Kane and 7 more97 min
Jun 12, 10:48 AM CDTMesoscale DiscussionSPCGallatin, Hardin, Massac, Pope2 hr
Jun 12, 3:51 PM CDTMesoscale DiscussionSPCAlexander, Franklin, Gallatin, Hamilton, Hardin, Jackson and 11 more84 min
Jun 12, 4:15 PM CDTSevere Thunderstorm WatchSPCAlexander, Gallatin, Hardin, Jackson, Johnson, Massac and 5 more5 hr
Jun 12, 6:08 PM CDTMesoscale DiscussionSPCAlexander, Gallatin, Hardin, Jackson, Johnson, Massac and 5 more37 min
Jun 11, 7:57 PM CDTMesoscale DiscussionSPCAllamakee, Black Hawk, Bremer, Buchanan, Butler, Calhoun and 26 more93 min
Jun 12, 11:45 AM CDTTornado WatchSPCAdair, Adams, Audubon, Boone, Buena Vista, Calhoun and 31 more7 hr
Jun 12, 12:43 PM CDTMesoscale DiscussionSPCAudubon, Cass, Crawford, Fremont, Harrison, Mills and 4 more92 min
Jun 12, 5:00 PM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Boone, Buena Vista, Calhoun and 29 more90 min

Nearby

Severe Thunderstorm Watches in Iowa, 2004Severe Thunderstorm Watches in Illinois, 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.