Alert archive / Missouri / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 735

August 7, 201112 counties in Kansas; 17 counties in Missouri

The Storm Prediction Center issued this severe thunderstorm watch at Aug 7, 2011, 12:55 PM CDT for 12 counties in Kansas; 17 counties in Missouri. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Aug 7, 2011, 12:55 PM CDT (17:55 UTC)
Expired
Aug 7, 2011, 5:49 PM CDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
65 kt
All 29 counties

Atchison County, KS, Douglas County, KS, Jackson County, KS, Jefferson County, KS, Johnson County, KS, Leavenworth County, KS, Linn County, KS, Miami County, KS, Pottawatomie County, KS, Shawnee County, KS, Wabaunsee County, KS, Wyandotte County, KS, Bates County, MO, Buchanan County, MO, Caldwell County, MO, Carroll County, MO, Cass County, MO, Clay County, MO, Clinton County, MO, Cooper County, MO, Henry County, MO, Howard County, MO, Jackson County, MO, Johnson County, MO, Lafayette County, MO, Pettis County, MO, Platte County, MO, Ray County, MO, Saline County, MO

The radar

The Pleasant Hill radar (KEAX), 100 km from the middle of the area, began a volume at 17:55 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
50%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Aug 7, 12:56 PM CDTSevere Thunderstorm WarningEAXAtchison34 min
Aug 7, 1:02 PM CDTSevere Thunderstorm WarningTOPJackson, Pottawatomie28 min
Aug 7, 1:23 PM CDTSevere Thunderstorm WarningTOPJackson, Pottawatomie, Shawnee, Wabaunsee37 min
Aug 7, 2:08 PM CDTSevere Thunderstorm WarningEAXJohnson, Leavenworth, Wyandotte22 min
Aug 7, 2:29 PM CDTSevere Thunderstorm WarningEAXJohnson, Leavenworth, Wyandotte31 min
Aug 7, 2:48 PM CDTSevere Thunderstorm WarningEAXWyandotte27 min
Aug 7, 2:48 PM CDTSevere Thunderstorm WarningTOPDouglas, Franklin27 min
Aug 7, 2:55 PM CDTSevere Thunderstorm WarningEAXJohnson, Miami22 min
Aug 7, 3:14 PM CDTSevere Thunderstorm WarningEAXJackson, Johnson, Lafayette, Ray31 min
Aug 7, 3:42 PM CDTSevere Thunderstorm WarningEAXJohnson, Lafayette, Pettis, Saline33 min
Aug 7, 4:13 PM CDTSevere Thunderstorm WarningEAXCooper, Howard, Pettis, Saline32 min
Aug 7, 4:42 PM CDTSevere Thunderstorm WarningEAXCooper, Howard33 min
Aug 7, 4:45 PM CDTSevere Thunderstorm WarningEAXHenry30 min
Aug 7, 5:14 PM CDTSevere Thunderstorm WarningEAXHenry16 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 12:00Z, 5.9 hours before the alert went out and 61 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-pSkew-T log-p diagram, Topeka, KS at 12:00Z on 2011-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 185 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Topeka, KS at 12:00Z on 2011-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 190 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
185 J/kg
Mixed-layer CIN
-540 J/kg
Mixed-layer LCL
1321 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
190 m²/s²
0-3 km storm-relative helicity
264 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.8

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 7, 10:48 AM CDTMesoscale DiscussionSPCAnderson, Atchison, Barton, Chase, Clay, Cloud and 33 more117 min
Aug 7, 2:21 PM CDTMesoscale DiscussionSPCClark, Comanche, Haskell, Meade, Seward, Stevens114 min
Aug 7, 3:16 PM CDTMesoscale DiscussionSPCAllen, Anderson, Bourbon, Coffey, Crawford, Douglas and 7 more119 min
Aug 7, 3:29 PM CDTSevere Thunderstorm WatchSPCBourbon, Crawford6 hr
Aug 7, 5:20 PM CDTMesoscale DiscussionSPCAllen, Bourbon, Cherokee, Crawford, Labette, Montgomery and 3 more115 min
Aug 7, 6:07 PM CDTSevere Thunderstorm WatchSPCChautauqua, Cherokee, Elk, Labette, Montgomery, Neosho and 1 more5 hr
Aug 6, 8:10 PM CDTMesoscale DiscussionSPCAndrew, Atchison, Daviess, DeKalb, Gentry, Grundy and 8 more2 hr
Aug 6, 10:14 PM CDTSevere Thunderstorm WatchSPCAdair, Chariton, Clark, Grundy, Knox, Lewis and 14 more5 hr
Aug 6, 11:06 PM CDTMesoscale DiscussionSPCAdair, Clark, Gentry, Grundy, Harrison, Knox and 11 more114 min
Aug 7, 5:41 PM CDTSevere Thunderstorm WatchSPCBollinger, Butler, Cape Girardeau, Carter, Franklin, Iron and 17 more6 hr

Nearby

Severe Thunderstorm Watches in Missouri, 2011Severe Thunderstorm Watches in Kansas, 2011Every 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.