Alert archive / Iowa / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 456

June 9, 201139 counties in Iowa; 23 counties in Missouri; 7 counties in Nebraska

The Storm Prediction Center issued this severe thunderstorm watch at Jun 9, 2011, 9:48 PM CDT for 39 counties in Iowa; 23 counties in Missouri; 7 counties in Nebraska. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Jun 9, 2011, 9:48 PM CDT (02:48 UTC)
Expired: Jun 10, 2011, 4:00 AM CDT
In force: 6 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2 in
Strongest gust expected: 60 kt

All 69 counties

Adair County, IA, Adams County, IA, Appanoose County, IA, Audubon County, IA, Boone 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, Guthrie 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, Shelby County, IA, Story County, IA, Tama County, IA, Taylor County, IA, Union County, IA, Van Buren County, IA, Wapello County, IA, Warren County, IA, Wayne County, IA, Adair County, MO, Andrew County, MO, Atchison County, MO, Clark County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Grundy County, MO, Harrison County, MO, Holt County, MO, Knox County, MO, Lewis County, MO, Linn County, MO, Livingston County, MO, Macon County, MO, Mercer County, MO, Nodaway County, MO, Putnam County, MO, Schuyler County, MO, Scotland County, MO, Shelby County, MO, Sullivan County, MO, Worth County, MO, Cass County, NE, Douglas County, NE, Nemaha County, NE, Otoe County, NE, Richardson County, NE, Sarpy County, NE, Washington County, NE

The radar

The Des Moines radar (KDMX), 87 km from the middle of the area, began a volume at 02:50 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: 20%
One or more EF2 to EF5 tornadoes: 5%
Ten or more severe wind reports: 30%
One or more gusts of 65 knots or more: 30%
Ten or more severe hail reports: 50%
One or more hailstones of 2 inches or more: 20%
Six or more combined severe hail and wind reports: 90%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jun 9, 9:55 PM CDT	Severe Thunderstorm Warning	LSX	Knox, Lewis	50 min
Jun 9, 9:58 PM CDT	Severe Thunderstorm Warning	EAX	Adair, Linn, Macon, Sullivan	32 min
Jun 9, 10:04 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Marion, Polk, Warren	41 min
Jun 9, 10:06 PM CDT	Flash Flood Warning	EAX	Grundy, Linn, Livingston	6 hr
Jun 9, 10:18 PM CDT	Severe Thunderstorm Warning	OAX	Fremont, Mills	27 min
Jun 9, 10:20 PM CDT	Severe Thunderstorm Warning	OAX	Fremont, Page	25 min
Jun 9, 10:27 PM CDT	Severe Thunderstorm Warning	EAX	Nodaway	18 min
Jun 9, 10:28 PM CDT	Severe Thunderstorm Warning	EAX	Adair, Linn, Macon	62 min
Jun 9, 10:28 PM CDT	Flash Flood Warning	LSX	Knox	6 hr
Jun 9, 10:29 PM CDT	Severe Thunderstorm Warning	DMX	Adams, Taylor	31 min
Jun 9, 10:31 PM CDT	Severe Thunderstorm Warning	OAX	Page	14 min
Jun 9, 10:34 PM CDT	Severe Thunderstorm Warning	DMX	Polk, Warren	26 min
Jun 9, 10:45 PM CDT	Severe Thunderstorm Warning	DMX	Dallas, Polk	31 min
Jun 9, 10:47 PM CDT	Severe Thunderstorm Warning	OAX	Mills, Montgomery, Pottawattamie	43 min
Jun 9, 10:49 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Mahaska, Marion	41 min
Jun 9, 10:53 PM CDT	Flash Flood Warning	LSX	Lewis	6 hr
Jun 9, 10:56 PM CDT	Severe Thunderstorm Warning	DMX	Madison, Warren	34 min
Jun 9, 11:07 PM CDT	Severe Thunderstorm Warning	OAX	Pottawattamie	38 min
Jun 9, 11:11 PM CDT	Flash Flood Warning	DMX	Jasper, Madison, Marion, Warren	6 hr
Jun 9, 11:13 PM CDT	Flash Flood Warning	DVN	Clark	6 hr
Jun 9, 11:14 PM CDT	Severe Thunderstorm Warning	DMX	Adair, Audubon, Cass	46 min
Jun 9, 11:16 PM CDT	Severe Thunderstorm Warning	LSX	Knox, Shelby	44 min
Jun 9, 11:36 PM CDT	Flash Flood Warning	DMX	Adair, Audubon, Dallas, Guthrie, Madison	4 hr
Jun 9, 11:36 PM CDT	Severe Thunderstorm Warning	OAX	Mills, Montgomery	39 min
Jun 10, 1:59 AM CDT	Severe Thunderstorm Warning	DMX	Adams, Ringgold, Union	46 min
Jun 10, 2:21 AM CDT	Flash Flood Warning	DMX	Mahaska, Marion, Monroe	6 hr

Discussions around it

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

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 9, 7:43 PM CDT	Mesoscale Discussion	SPC	Appanoose, Decatur, Fremont, Page, Ringgold, Taylor and 1 more	92 min
Jun 9, 11:45 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Appanoose, Audubon, Boone, Carroll and 33 more	90 min
Jun 10, 1:39 AM CDT	Mesoscale Discussion	SPC	Adair, Adams, Appanoose, Audubon, Boone, Carroll and 36 more	2 hr
Jun 9, 9:56 PM CDT	Mesoscale Discussion	SPC	Allen, Bourbon, Chautauqua, Cherokee, Cowley, Crawford and 6 more	79 min
Jun 10, 4:18 PM CDT	Mesoscale Discussion	SPC	Allen, Anderson, Bourbon, Chautauqua, Cherokee, Coffey and 15 more	87 min
Jun 10, 4:57 PM CDT	Severe Thunderstorm Watch	SPC	Allen, Anderson, Bourbon, Chautauqua, Cherokee, Coffey and 17 more	7 hr
Jun 9, 8:09 PM CDT	Mesoscale Discussion	SPC	Sioux	96 min

Nearby

Severe Thunderstorm Watches in Iowa, 2011 Severe Thunderstorm Watches in Missouri, 2011 Severe Thunderstorm Watches in Nebraska, 2011 Every severe thunderstorm watch in 2011

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; radar from the NEXRAD Level II archive.