Alert archive / Iowa / Severe Thunderstorm Watches in 2004

Severe Thunderstorm Watch 615

July 12, 200438 counties in Iowa; Atchison County, Holt County, Missouri; 13 counties in Nebraska

The Storm Prediction Center issued this severe thunderstorm watch at Jul 12, 2004, 9:15 PM CDT for 38 counties in Iowa; Atchison County, Holt County, Missouri; 13 counties in Nebraska. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Jul 12, 2004, 9:15 PM CDT (02:15 UTC)
Expired: Jul 13, 2004, 4:00 AM CDT
In force: 7 hr
Issued by: the Storm Prediction Center

All 53 counties

Adair County, IA, Adams County, IA, Audubon County, IA, Boone County, IA, Buena Vista County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Cerro Gordo County, IA, Cherokee County, IA, Clay County, IA, Crawford County, IA, Dallas County, IA, Dickinson County, IA, Emmet County, IA, Fremont County, IA, Greene County, IA, Guthrie County, IA, Hamilton County, IA, Hancock County, IA, Harrison County, IA, Humboldt County, IA, Ida County, IA, Kossuth County, IA, Mills 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, Taylor County, IA, Webster County, IA, Winnebago County, IA, Worth County, IA, Wright County, IA, Atchison County, MO, Holt County, MO, Cass County, NE, Douglas County, NE, Gage County, NE, Jefferson County, NE, Johnson County, NE, Lancaster County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Richardson County, NE, Sarpy County, NE, Saunders County, NE, Washington County, NE

The radar

The Omaha radar (KOAX), 66 km from the middle of the area, began a volume at 02:17 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

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

Issued	Product	Office	Counties	Lasted
Jul 12, 9:27 PM CDT	Severe Thunderstorm Warning	OAX	Harrison	48 min
Jul 12, 9:36 PM CDT	Severe Thunderstorm Warning	OAX	Pottawattamie	39 min
Jul 12, 9:49 PM CDT	Severe Thunderstorm Warning	OAX	Washington	26 min
Jul 12, 10:04 PM CDT	Severe Thunderstorm Warning	OAX	Mills	41 min
Jul 12, 10:18 PM CDT	Severe Thunderstorm Warning	OAX	Pottawattamie	27 min
Jul 12, 11:35 PM CDT	Severe Thunderstorm Warning	DMX	Emmet, Palo Alto	40 min
Jul 12, 11:59 PM CDT	Severe Thunderstorm Warning	FSD	Cherokee, Plymouth	31 min
Jul 13, 12:15 AM CDT	Severe Thunderstorm Warning	DMX	Emmet	45 min
Jul 13, 12:20 AM CDT	Tornado Warning	DMX	Emmet	40 min
Jul 13, 12:37 AM CDT	Flash Flood Warning	DMX	Emmet	3 hr
Jul 13, 12:40 AM CDT	Severe Thunderstorm Warning	FSD	Cherokee	35 min
Jul 13, 12:58 AM CDT	Severe Thunderstorm Warning	FSD	Buena Vista, Clay	62 min
Jul 13, 1:51 AM CDT	Severe Thunderstorm Warning	FSD	Cherokee	39 min
Jul 13, 1:58 AM CDT	Severe Thunderstorm Warning	FSD	Buena Vista, Clay	47 min
Jul 13, 2:33 AM CDT	Severe Thunderstorm Warning	DMX	Kossuth	42 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 00:00Z, 2.3 hours before the alert went out and 66 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 4686 J/kg
Mixed-layer CIN: -62 J/kg
Mixed-layer LCL: 1125 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 101 m²/s²
0-3 km storm-relative helicity: 194 m²/s²
Significant tornado parameter: 3.2
Supercell composite: 20.9

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 12, 9:19 PM CDT	Mesoscale Discussion	SPC	Clay, Dickinson, Emmet, Hancock, Kossuth, Lyon and 5 more	116 min
Jul 12, 11:19 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Cass, Decatur, Fremont, Mills and 6 more	116 min
Jul 12, 11:52 PM CDT	Mesoscale Discussion	SPC	Cherokee, Dickinson, Lyon, O'Brien, Osceola, Plymouth and 1 more	53 min
Jul 13, 12:55 AM CDT	Severe Thunderstorm Watch	SPC	Adair, Audubon, Benton, Black Hawk, Boone, Bremer and 52 more	6 hr
Jul 13, 4:21 AM CDT	Mesoscale Discussion	SPC	Allamakee, Benton, Black Hawk, Bremer, Buchanan, Butler and 22 more	54 min
Jul 13, 10:32 AM CDT	Mesoscale Discussion	SPC	Cedar, Clinton, Delaware, Dubuque, Jackson, Johnson and 4 more	118 min
Jul 13, 10:55 AM CDT	Tornado Watch	SPC	Cedar, Clinton, Delaware, Dubuque, Jackson, Jones and 3 more	6 hr
Jul 13, 1:39 PM CDT	Mesoscale Discussion	SPC	Cedar, Clinton, Delaware, Dubuque, Jackson, Jones and 3 more	66 min
Jul 13, 2:25 PM CDT	Severe Thunderstorm Watch	SPC	Fremont, Harrison, Mills, Monona, Pottawattamie, Shelby	6 hr
Jul 13, 6:34 PM CDT	Mesoscale Discussion	SPC	Adair, Andrew, Audrain, Benton, Boone, Buchanan and 62 more	116 min
Jul 12, 7:45 PM CDT	Mesoscale Discussion	SPC	Boone, Butler, Colfax, Cuming, Dodge, Greeley and 14 more	2 hr
Jul 12, 8:40 PM CDT	Tornado Watch	SPC	Adams, Buffalo, Clay, Franklin, Hall, Hamilton and 10 more	5 hr
Jul 13, 3:27 PM CDT	Mesoscale Discussion	SPC	Arthur, Banner, Box Butte, Chase, Cheyenne, Deuel and 11 more	3 hr
Jul 13, 4:10 PM CDT	Severe Thunderstorm Watch	SPC	Arthur, Banner, Box Butte, Chase, Cheyenne, Dawes and 10 more	6 hr

Nearby

Severe Thunderstorm Watches in Iowa, 2004 Severe Thunderstorm Watches in Nebraska, 2004 Severe Thunderstorm Watches in Missouri, 2004 Every 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.