Alert archive / Iowa / Tornado Watches in 2010

Tornado Watch 343

June 18, 201045 counties in Iowa

The Storm Prediction Center issued this tornado watch at Jun 18, 2010, 2:49 PM CDT for 45 counties in Iowa. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Jun 18, 2010, 2:49 PM CDT (19:49 UTC)
Expired: Jun 18, 2010, 10:00 PM CDT
In force: 7 hr
Issued by: the Storm Prediction Center
Largest hail expected: 3.5 in
Strongest gust expected: 70 kt

All 45 counties

Adair County, IA, Adams County, IA, Appanoose County, IA, Audubon County, IA, Black Hawk County, IA, Boone County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Clarke County, IA, Crawford County, IA, Dallas County, IA, Davis County, IA, Decatur County, IA, Fremont County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hardin County, IA, Harrison County, IA, Jasper County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Mills County, IA, Monroe County, IA, Montgomery County, IA, Page County, IA, Polk County, IA, Pottawattamie County, IA, Poweshiek County, IA, Ringgold County, IA, Sac County, IA, Shelby County, IA, Story County, IA, Tama County, IA, Taylor County, IA, Union County, IA, Wapello County, IA, Warren County, IA, Wayne County, IA, Webster County, IA

The radar

The Des Moines radar (KDMX), 3 km from the middle of the area, began a volume at 19:49 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes: 40%
One or more EF2 to EF5 tornadoes: 20%
Ten or more severe wind reports: 60%
One or more gusts of 65 knots or more: 40%
Ten or more severe hail reports: 80%
One or more hailstones of 2 inches or more: 60%
Six or more combined severe hail and wind reports: 90%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jun 18, 3:34 PM CDT	Severe Thunderstorm Warning	DMX	Butler, Grundy	41 min
Jun 18, 4:33 PM CDT	Severe Thunderstorm Warning	DMX	Hamilton, Hardin, Marshall, Story	28 min
Jun 18, 4:37 PM CDT	Severe Thunderstorm Warning	DMX	Dallas, Madison, Polk	33 min
Jun 18, 4:41 PM CDT	Severe Thunderstorm Warning	DMX	Madison, Polk, Warren	49 min
Jun 18, 4:42 PM CDT	Severe Thunderstorm Warning	DMX	Grundy, Hardin, Marshall, Tama	48 min
Jun 18, 4:49 PM CDT	Severe Thunderstorm Warning	DMX	Madison	26 min
Jun 18, 5:00 PM CDT	Tornado Warning	DMX	Madison, Warren	35 min
Jun 18, 5:09 PM CDT	Severe Thunderstorm Warning	DMX	Black Hawk, Grundy, Tama	51 min
Jun 18, 5:11 PM CDT	Severe Thunderstorm Warning	DMX	Adair, Cass	49 min
Jun 18, 5:17 PM CDT	Severe Thunderstorm Warning	DMX	Lucas, Marion, Warren	43 min
Jun 18, 5:21 PM CDT	Flash Flood Warning	DMX	Black Hawk	6 hr
Jun 18, 5:24 PM CDT	Severe Thunderstorm Warning	DMX	Marshall, Story	51 min
Jun 18, 5:52 PM CDT	Tornado Warning	DMX	Marion, Monroe	38 min
Jun 18, 6:02 PM CDT	Severe Thunderstorm Warning	DMX	Appanoose, Lucas, Marion, Monroe, Warren	43 min
Jun 18, 6:05 PM CDT	Severe Thunderstorm Warning	DMX	Tama	40 min
Jun 18, 6:07 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Madison, Union	38 min
Jun 18, 6:09 PM CDT	Flash Flood Warning	DMX	Tama	4 hr
Jun 18, 6:21 PM CDT	Severe Thunderstorm Warning	DMX	Mahaska, Marion, Monroe, Wapello	39 min
Jun 18, 6:54 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Ringgold, Union	51 min
Jun 18, 6:58 PM CDT	Severe Thunderstorm Warning	DMX	Appanoose, Davis, Mahaska, Monroe, Wapello	47 min
Jun 18, 7:00 PM CDT	Flash Flood Warning	DMX	Marion	6 hr
Jun 18, 7:17 PM CDT	Flash Flood Warning	DMX	Clarke, Union	4 hr
Jun 18, 7:20 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Mahaska, Marion, Poweshiek	40 min
Jun 18, 7:21 PM CDT	Tornado Warning	DMX	Clarke, Decatur, Lucas, Wayne	24 min
Jun 18, 7:36 PM CDT	Severe Thunderstorm Warning	DMX	Appanoose, Lucas, Monroe, Wayne	39 min
Jun 18, 7:41 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Decatur, Lucas, Wayne	49 min
Jun 18, 7:59 PM CDT	Severe Thunderstorm Warning	DMX	Appanoose, Wayne	31 min
Jun 18, 8:14 PM CDT	Severe Thunderstorm Warning	DMX	Appanoose, Lucas, Monroe, Wayne	16 min
Jun 18, 8:22 PM CDT	Severe Thunderstorm Warning	DMX	Appanoose, Davis, Lucas, Monroe, Wapello, Wayne	53 min
Jun 18, 8:36 PM CDT	Flash Flood Warning	DMX	Appanoose, Davis	6 hr
Jun 18, 9:16 PM CDT	Severe Thunderstorm Warning	DMX	Appanoose, Davis, Wayne	44 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, 7.8 hours before the alert went out and 225 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: 2585 J/kg
Mixed-layer CIN: -94 J/kg
Mixed-layer LCL: 801 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 94 m²/s²
0-3 km storm-relative helicity: 105 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 5.1

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 17, 7:39 PM CDT	Mesoscale Discussion	SPC	Allamakee, Audubon, Benton, Black Hawk, Boone, Bremer and 46 more	96 min
Jun 17, 7:55 PM CDT	Mesoscale Discussion	SPC	Mills	65 min
Jun 17, 9:01 PM CDT	Severe Thunderstorm Watch	SPC	Adair, Adams, Appanoose, Audubon, Benton, Black Hawk and 50 more	6 hr
Jun 17, 9:43 PM CDT	Mesoscale Discussion	SPC	Allamakee, Howard, Mitchell, Winneshiek	62 min
Jun 17, 10:57 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Appanoose, Benton, Black Hawk, Buchanan and 43 more	93 min
Jun 18, 2:33 AM CDT	Mesoscale Discussion	SPC	Des Moines, Henry, Louisa, Muscatine, Scott, Washington	27 min
Jun 18, 7:47 AM CDT	Mesoscale Discussion	SPC	Adair, Audubon, Boone, Calhoun, Carroll, Cass and 20 more	88 min
Jun 18, 9:06 AM CDT	Severe Thunderstorm Watch	SPC	Adams, Appanoose, Benton, Black Hawk, Boone, Bremer and 46 more	7 hr
Jun 18, 10:41 AM CDT	Mesoscale Discussion	SPC	Appanoose, Cedar, Clayton, Clinton, Davis, Decatur and 19 more	2 hr
Jun 18, 12:14 PM CDT	Mesoscale Discussion	SPC	Cedar, Clinton, Des Moines, Dubuque, Jackson, Jones and 3 more	61 min
Jun 18, 12:29 PM CDT	Severe Thunderstorm Watch	SPC	Benton, Buchanan, Cedar, Clinton, Delaware, Des Moines and 15 more	9 hr
Jun 18, 1:37 PM CDT	Mesoscale Discussion	SPC	Butler, Calhoun, Floyd, Franklin, Humboldt, Ida and 4 more	113 min
Jun 18, 1:56 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Cass, Clarke, Decatur, Fremont and 10 more	94 min
Jun 18, 5:06 PM CDT	Mesoscale Discussion	SPC	Buchanan, Cedar, Clinton, Delaware, Dubuque, Jackson and 6 more	54 min
Jun 18, 5:45 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Appanoose, Benton, Black Hawk, Buchanan and 37 more	60 min

Nearby

Tornado Watches in Iowa, 2010 Every tornado watch in 2010

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.