Alert archive / Iowa / Tornado Watches in 2009

Tornado Watch 194

April 26, 20094 states

The Storm Prediction Center issued this tornado watch at Apr 26, 2009, 5:02 PM CDT for 4 states. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Apr 26, 2009, 5:02 PM CDT (22:02 UTC)
Expired: Apr 26, 2009, 11:24 PM CDT
In force: 6 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2 in
Strongest gust expected: 60 kt

All 97 counties

Adair County, IA, Adams County, IA, Allamakee County, IA, Appanoose County, IA, Benton County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Buchanan County, IA, Butler County, IA, Cass County, IA, Clarke County, IA, Clayton County, IA, Dallas County, IA, Davis County, IA, Decatur County, IA, Delaware County, IA, Dubuque County, IA, Fayette County, IA, Franklin County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hardin County, IA, Iowa County, IA, Jackson County, IA, Jasper County, IA, Jones County, IA, Keokuk County, IA, Linn County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Monroe County, IA, Polk County, IA, Poweshiek County, IA, Ringgold County, IA, Story County, IA, Tama County, IA, Taylor County, IA, Union County, IA, Wapello County, IA, Warren County, IA, Wayne County, IA, Anderson County, KS, Atchison County, KS, Brown County, KS, Coffey County, KS, Doniphan County, KS, Douglas County, KS, Franklin County, KS, Jackson County, KS, Jefferson County, KS, Johnson County, KS, Leavenworth County, KS, Linn County, KS, Lyon County, KS, Miami County, KS, Morris County, KS, Osage County, KS, Shawnee County, KS, Wabaunsee County, KS, Wyandotte County, KS, Andrew County, MO, Atchison County, MO, Buchanan County, MO, Caldwell County, MO, Cass County, MO, Clay County, MO, Clinton County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Grundy County, MO, Harrison County, MO, Holt County, MO, Jackson County, MO, Livingston County, MO, Mercer County, MO, Nodaway County, MO, Platte County, MO, Putnam County, MO, Ray County, MO, Schuyler County, MO, Sullivan County, MO, Worth County, MO, Crawford County, WI, Dane County, WI, Grant County, WI, Green County, WI, Iowa County, WI, Lafayette County, WI, Richland County, WI, Sauk County, WI

The radar

The Pleasant Hill radar (KEAX), 146 km from the middle of the area, began a volume at 22:03 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: 30%
One or more gusts of 65 knots or more: 30%
Ten or more severe hail reports: 60%
One or more hailstones of 2 inches or more: 30%
Six or more combined severe hail and wind reports: 80%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Apr 26, 5:05 PM CDT	Tornado Warning	EAX	Atchison, Nodaway	15 min
Apr 26, 5:12 PM CDT	Tornado Warning	DVN	Delaware, Dubuque, Jones, Linn	48 min
Apr 26, 5:43 PM CDT	Severe Thunderstorm Warning	EAX	Gentry, Nodaway, Worth	22 min
Apr 26, 5:48 PM CDT	Tornado Warning	DVN	Delaware, Dubuque	42 min
Apr 26, 5:50 PM CDT	Severe Thunderstorm Warning	TOP	Dickinson, Geary, Morris, Riley, Wabaunsee	40 min
Apr 26, 5:58 PM CDT	Severe Thunderstorm Warning	TOP	Pottawatomie, Wabaunsee	27 min
Apr 26, 6:04 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Decatur, Ringgold, Union	41 min
Apr 26, 6:08 PM CDT	Tornado Warning	DMX	Black Hawk, Tama	37 min
Apr 26, 6:13 PM CDT	Flash Flood Warning	TOP	Dickinson, Geary, Morris	4 hr
Apr 26, 6:23 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Marshall, Poweshiek, Tama	37 min
Apr 26, 6:23 PM CDT	Tornado Warning	ARX	Grant	67 min
Apr 26, 6:27 PM CDT	Tornado Warning	DVN	Dubuque	18 min
Apr 26, 6:29 PM CDT	Flash Flood Warning	DMX	Marshall	6 hr
Apr 26, 6:30 PM CDT	Flash Flood Warning	DVN	Delaware	5 hr
Apr 26, 6:36 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Decatur, Lucas, Marion, Warren	39 min
Apr 26, 6:38 PM CDT	Severe Thunderstorm Warning	TOP	Jackson, Jefferson, Nemaha, Shawnee	37 min
Apr 26, 6:39 PM CDT	Severe Thunderstorm Warning	DMX	Marion, Polk, Warren	51 min
Apr 26, 6:50 PM CDT	Severe Thunderstorm Warning	DMX	Appanoose, Decatur, Lucas, Monroe, Wayne	40 min
Apr 26, 6:56 PM CDT	Severe Thunderstorm Warning	DMX	Tama	26 min
Apr 26, 6:58 PM CDT	Severe Thunderstorm Warning	DMX	Marion	47 min
Apr 26, 6:59 PM CDT	Flash Flood Warning	DMX	Grundy, Marshall, Tama	6 hr
Apr 26, 7:02 PM CDT	Severe Thunderstorm Warning	EAX	Atchison, Doniphan	28 min
Apr 26, 7:11 PM CDT	Flash Flood Warning	ARX	Clayton, Fayette	6 hr
Apr 26, 7:12 PM CDT	Severe Thunderstorm Warning	TOP	Dickinson, Geary, Lyon, Morris, Riley, Wabaunsee	48 min
Apr 26, 7:16 PM CDT	Flash Flood Warning	DVN	Benton, Buchanan	5 hr
Apr 26, 7:26 PM CDT	Severe Thunderstorm Warning	EAX	Doniphan	34 min
Apr 26, 7:44 PM CDT	Severe Thunderstorm Warning	TOP	Lyon, Morris, Wabaunsee	46 min
Apr 26, 7:53 PM CDT	Tornado Warning	EAX	Doniphan	22 min
Apr 26, 8:02 PM CDT	Tornado Warning	TOP	Wabaunsee	17 min
Apr 26, 8:07 PM CDT	Flash Flood Warning	TOP	Jackson, Pottawatomie, Shawnee, Wabaunsee	4 hr
Apr 26, 8:56 PM CDT	Flash Flood Warning	TOP	Douglas, Jefferson	3 hr
Apr 26, 9:14 PM CDT	Flash Flood Warning	TOP	Shawnee	3 hr
Apr 26, 9:36 PM CDT	Flash Flood Warning	TOP	Anderson, Coffey, Douglas, Franklin, Lyon, Osage and 1 more	4 hr
Apr 26, 9:47 PM CDT	Flash Flood Warning	TOP	Jefferson	2 hr
Apr 26, 10:20 PM CDT	Flash Flood Warning	TOP	Dickinson, Geary, Morris, Pottawatomie, Riley, Wabaunsee	3 hr
Apr 26, 10:34 PM CDT	Flash Flood Warning	EAX	Leavenworth, Wyandotte	6 hr

Discussions around it

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

The nearest sounding before it

Topeka, KS (KTOP), launched 12:00Z, 10.0 hours before the alert went out and 164 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2039 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 200 m²/s²
0-3 km storm-relative helicity: 301 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 25, 7:17 PM CDT	Mesoscale Discussion	SPC	Appanoose, Davis, Wapello, Wayne	58 min
Apr 25, 9:23 PM CDT	Mesoscale Discussion	SPC	Davis, Des Moines, Henry, Lee, Van Buren	67 min
Apr 25, 10:09 PM CDT	Severe Thunderstorm Watch	SPC	Fremont, Page	6 hr
Apr 26, 9:18 AM CDT	Mesoscale Discussion	SPC	Audubon, Crawford, Harrison, Mills, Monona, Pottawattamie and 2 more	27 min
Apr 26, 9:34 AM CDT	Severe Thunderstorm Watch	SPC	Audubon, Buena Vista, Calhoun, Carroll, Cass, Cherokee and 29 more	6 hr
Apr 26, 12:30 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Audubon, Boone, Cass, Dallas and 13 more	60 min
Apr 26, 12:48 PM CDT	Tornado Watch	SPC	Adair, Adams, Audubon, Boone, Butler, Calhoun and 33 more	4 hr
Apr 26, 2:41 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Audubon, Boone, Buena Vista, Calhoun and 35 more	3 hr
Apr 26, 5:14 PM CDT	Mesoscale Discussion	SPC	Clayton, Delaware, Dubuque, Jackson	61 min
Apr 26, 6:14 PM CDT	Mesoscale Discussion	SPC	Adams, Appanoose, Benton, Black Hawk, Bremer, Buchanan and 40 more	61 min
Apr 25, 9:58 PM CDT	Mesoscale Discussion	SPC	Allen, Anderson, Butler, Chase, Chautauqua, Clay and 40 more	92 min
Apr 25, 10:39 PM CDT	Tornado Watch	SPC	Allen, Chautauqua, Cowley, Elk, Harper, Labette and 5 more	4 hr
Apr 26, 1:28 AM CDT	Mesoscale Discussion	SPC	Allen, Barber, Chautauqua, Cowley, Elk, Greenwood and 7 more	92 min
Apr 26, 2:10 AM CDT	Mesoscale Discussion	SPC	Anderson, Atchison, Brown, Clay, Coffey, Dickinson and 20 more	95 min
Apr 26, 2:39 AM CDT	Tornado Watch	SPC	Allen, Chautauqua, Cowley, Elk, Harper, Labette and 5 more	3 hr
Apr 26, 5:47 AM CDT	Mesoscale Discussion	SPC	Barton, Dickinson, Edwards, Ellsworth, Ford, Lincoln and 8 more	58 min
Apr 26, 5:58 AM CDT	Tornado Watch	SPC	Barton, Chase, Clark, Clay, Comanche, Dickinson and 24 more	7 hr
Apr 26, 10:19 AM CDT	Mesoscale Discussion	SPC	Barber, Butler, Comanche, Cowley, Dickinson, Ellsworth and 14 more	56 min
Apr 26, 10:54 AM CDT	Mesoscale Discussion	SPC	Atchison, Barber, Barton, Butler, Chase, Chautauqua and 42 more	66 min
Apr 26, 11:07 AM CDT	Tornado Watch PDS	SPC	Barber, Barton, Brown, Butler, Chase, Clark and 40 more	7 hr
Apr 26, 12:27 PM CDT	Mesoscale Discussion	SPC	Barton, Clark, Clay, Cloud, Edwards, Ellsworth and 12 more	2 hr
Apr 26, 5:44 PM CDT	Mesoscale Discussion	SPC	Barber, Butler, Cowley, Harper, Harvey, Kingman and 5 more	61 min
Apr 26, 6:16 PM CDT	Tornado Watch PDS	SPC	Allen, Barber, Butler, Chase, Chautauqua, Comanche and 16 more	8 hr
Apr 26, 2:00 PM CDT	Mesoscale Discussion	SPC	Dane, Green, Jefferson, Lafayette, Rock, Walworth and 1 more	60 min

Nearby

Tornado Watches in Iowa, 2009 Tornado Watches in Missouri, 2009 Tornado Watches in Kansas, 2009 Every tornado watch in 2009

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.