Alert archive / Missouri / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 109

April 8, 201141 counties in Kansas; 48 counties in Missouri

The Storm Prediction Center issued this severe thunderstorm watch at Apr 8, 2011, 9:01 PM CDT for 41 counties in Kansas; 48 counties in Missouri. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Apr 8, 2011, 9:01 PM CDT (02:01 UTC)
Expired: Apr 9, 2011, 4:00 AM CDT
In force: 7 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2 in
Strongest gust expected: 60 kt

All 89 counties

Allen County, KS, Atchison County, KS, Bourbon County, KS, Brown County, KS, Butler County, KS, Chautauqua County, KS, Cherokee County, KS, Clay County, KS, Cowley County, KS, Crawford County, KS, Dickinson County, KS, Doniphan County, KS, Douglas County, KS, Elk County, KS, Geary County, KS, Greenwood County, KS, Jackson County, KS, Jefferson County, KS, Johnson County, KS, Kingman County, KS, Labette County, KS, Leavenworth County, KS, Linn County, KS, Marion County, KS, Marshall County, KS, McPherson County, KS, Miami County, KS, Montgomery County, KS, Morris County, KS, Nemaha County, KS, Neosho County, KS, Ottawa County, KS, Pottawatomie County, KS, Reno County, KS, Riley County, KS, Saline County, KS, Shawnee County, KS, Wabaunsee County, KS, Wilson County, KS, Woodson County, KS, Wyandotte County, KS, Audrain County, MO, Barton County, MO, Bates County, MO, Benton County, MO, Boone County, MO, Buchanan County, MO, Caldwell County, MO, Callaway County, MO, Camden County, MO, Carroll County, MO, Cass County, MO, Cedar County, MO, Chariton County, MO, Clay County, MO, Clinton County, MO, Cole County, MO, Cooper County, MO, Dade County, MO, Dallas County, MO, Greene County, MO, Henry County, MO, Hickory County, MO, Howard County, MO, Jackson County, MO, Jasper County, MO, Johnson County, MO, Laclede County, MO, Lafayette County, MO, Lawrence County, MO, Maries County, MO, Miller County, MO, Moniteau County, MO, Monroe County, MO, Morgan County, MO, Osage County, MO, Pettis County, MO, Phelps County, MO, Platte County, MO, Polk County, MO, Pulaski County, MO, Randolph County, MO, Ray County, MO, Saline County, MO, St. Clair County, MO, Texas County, MO, Vernon County, MO, Webster County, MO, Wright County, MO

The radar

The Topeka radar (KTWX), 77 km from the middle of the area, began a volume at 02:03 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: 10%
One or more EF2 to EF5 tornadoes: 5%
Ten or more severe wind reports: 30%
One or more gusts of 65 knots or more: 10%
Ten or more severe hail reports: 80%
One or more hailstones of 2 inches or more: 20%
Six or more combined severe hail and wind reports: 95%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Apr 8, 9:03 PM CDT	Severe Thunderstorm Warning	ICT	Butler, Cowley, Sedgwick, Sumner	57 min
Apr 8, 9:15 PM CDT	Severe Thunderstorm Warning	EAX	Clay, Platte	30 min
Apr 8, 9:26 PM CDT	Severe Thunderstorm Warning	EAX	Clay, Ray	34 min
Apr 8, 9:34 PM CDT	Severe Thunderstorm Warning	EAX	Linn, Miami	26 min
Apr 8, 9:43 PM CDT	Severe Thunderstorm Warning	TOP	Geary, Morris, Wabaunsee	47 min
Apr 8, 9:45 PM CDT	Severe Thunderstorm Warning	ICT	Cowley	20 min
Apr 8, 9:54 PM CDT	Tornado Warning	TOP	Morris	26 min
Apr 8, 9:59 PM CDT	Severe Thunderstorm Warning	EAX	Linn, Miami	31 min
Apr 8, 10:08 PM CDT	Severe Thunderstorm Warning	EAX	Ray	23 min
Apr 8, 10:28 PM CDT	Severe Thunderstorm Warning	TOP	Morris	31 min
Apr 8, 10:30 PM CDT	Severe Thunderstorm Warning	ICT	Allen, Neosho, Wilson, Woodson	25 min
Apr 8, 10:49 PM CDT	Severe Thunderstorm Warning	TOP	Jefferson	18 min
Apr 8, 10:51 PM CDT	Severe Thunderstorm Warning	ICT	Elk, Greenwood	54 min
Apr 8, 10:53 PM CDT	Severe Thunderstorm Warning	ICT	Butler	27 min
Apr 8, 10:56 PM CDT	Severe Thunderstorm Warning	EAX	Atchison	36 min
Apr 8, 11:22 PM CDT	Severe Thunderstorm Warning	EAX	Buchanan, Clinton	23 min
Apr 8, 11:27 PM CDT	Severe Thunderstorm Warning	EAX	Carroll, Ray	33 min
Apr 8, 11:37 PM CDT	Severe Thunderstorm Warning	ICT	Elk, Greenwood, Wilson, Woodson	47 min
Apr 8, 11:37 PM CDT	Severe Thunderstorm Warning	EAX	Caldwell, Carroll, Livingston	23 min
Apr 9, 12:21 AM CDT	Severe Thunderstorm Warning	ICT	Labette, Neosho	39 min
Apr 9, 12:37 AM CDT	Severe Thunderstorm Warning	SGF	Cherokee, Crawford	38 min
Apr 9, 12:45 AM CDT	Severe Thunderstorm Warning	SGF	Barton, Jasper	45 min
Apr 9, 1:18 AM CDT	Severe Thunderstorm Warning	SGF	Cedar, Dade	42 min
Apr 9, 1:57 AM CDT	Severe Thunderstorm Warning	SGF	Cedar, Dade, Hickory, Polk, St. Clair	48 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

Topeka, KS (KTOP), launched 00:00Z, 2.0 hours before the alert went out and 29 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: 1028 J/kg
Mixed-layer CIN: -353 J/kg
Mixed-layer LCL: 980 m above ground
0-6 km bulk shear: 62 kt
0-1 km storm-relative helicity: 354 m²/s²
0-3 km storm-relative helicity: 409 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.2

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 8, 8:32 PM CDT	Mesoscale Discussion	SPC	Allen, Anderson, Bourbon, Butler, Chase, Chautauqua and 30 more	88 min
Apr 8, 11:01 PM CDT	Mesoscale Discussion	SPC	Allen, Anderson, Butler, Chautauqua, Cherokee, Coffey and 9 more	59 min
Apr 8, 11:26 PM CDT	Mesoscale Discussion	SPC	Atchison, Bourbon, Doniphan, Douglas, Jackson, Jefferson and 7 more	94 min
Apr 9, 1:52 AM CDT	Mesoscale Discussion	SPC	Cherokee	53 min
Apr 9, 4:12 AM CDT	Mesoscale Discussion	SPC	Lincoln, Saint Charles, Saint Louis, City of Saint Louis	93 min
Apr 9, 7:25 AM CDT	Severe Thunderstorm Watch	SPC	Mississippi, New Madrid	6 hr

Nearby

Severe Thunderstorm Watches in Missouri, 2011 Severe Thunderstorm Watches in Kansas, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.