Alert archive / Missouri / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 42

February 28, 20124 counties in Kansas; 15 counties in Missouri

The Storm Prediction Center issued this severe thunderstorm watch at Feb 28, 2012, 10:07 PM CST for 4 counties in Kansas; 15 counties in Missouri. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Feb 28, 2012, 10:07 PM CST (04:07 UTC)
Expired: Feb 29, 2012, 1:10 AM CST
In force: 3 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1 in
Strongest gust expected: 60 kt

Counties Johnson County, KS, Linn County, KS, Miami County, KS, Wyandotte County, KS, Bates County, MO, Caldwell County, MO, Carroll County, MO, Cass County, MO, Clay County, MO, Clinton County, MO, Cooper County, MO, Henry 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), 26 km from the middle of the area, began a volume at 04:08 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: 10%
One or more hailstones of 2 inches or more: 10%
Six or more combined severe hail and wind reports: 50%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Feb 28, 10:16 PM CST	Severe Thunderstorm Warning	EAX	Johnson, Wyandotte	29 min
Feb 28, 10:30 PM CST	Severe Thunderstorm Warning	EAX	Johnson, Leavenworth, Wyandotte	30 min
Feb 28, 10:55 PM CST	Severe Thunderstorm Warning	EAX	Clay, Jackson, Lafayette, Ray	26 min
Feb 28, 11:02 PM CST	Severe Thunderstorm Warning	EAX	Caldwell, Carroll, Chariton, Linn, Livingston	28 min
Feb 28, 11:31 PM CST	Severe Thunderstorm Warning	EAX	Carroll, Chariton, Linn, Macon	29 min

Discussions around it

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

Mesoscale Discussion 173Feb 28, 9:47 PM CST

The nearest sounding before it

Topeka, KS (KTOP), launched 00:00Z, 4.1 hours before the alert went out and 123 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: 37 J/kg
Mixed-layer CIN: -41 J/kg
Mixed-layer LCL: 482 m above ground
0-6 km bulk shear: 72 kt
0-1 km storm-relative helicity: 427 m²/s²
0-3 km storm-relative helicity: 451 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.8

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 28, 7:57 PM CST	Mesoscale Discussion	SPC	Butler, Chase, Chautauqua, Cowley, Elk, Greenwood and 9 more	48 min
Feb 28, 7:59 PM CST	Mesoscale Discussion	SPC	Clay, Cloud, Jewell, Mitchell, Osborne, Ottawa and 5 more	31 min
Feb 28, 8:10 PM CST	Tornado Watch	SPC	Allen, Anderson, Brown, Butler, Chase, Chautauqua and 25 more	5 hr
Feb 28, 9:47 PM CST	Mesoscale Discussion	SPC	Allen, Anderson, Bourbon, Cherokee, Crawford, Franklin and 9 more	58 min
Feb 28, 10:30 PM CST	Tornado Watch	SPC	Bourbon, Cherokee, Crawford	6 hr
Feb 28, 8:23 PM CST	Mesoscale Discussion	SPC	Atchison, Holt, Nodaway	37 min
Feb 28, 11:40 PM CST	Mesoscale Discussion	SPC	Barry, Camden, Cedar, Christian, Dade, Dallas and 13 more	95 min
Feb 29, 12:49 AM CST	Mesoscale Discussion	SPC	Bollinger, Butler, Cape Girardeau, Carter, Dunklin, Franklin and 19 more	56 min
Feb 29, 1:14 AM CST	Tornado Watch	SPC	Bollinger, Butler, Cape Girardeau, Carter, Crawford, Franklin and 19 more	11 hr
Feb 29, 3:20 AM CST	Tornado Watch	SPC	Dunklin, Pemiscot	9 hr
Feb 29, 3:53 AM CST	Mesoscale Discussion	SPC	Bollinger, Butler, Cape Girardeau, Carter, Dunklin, Madison and 9 more	97 min
Feb 29, 8:07 AM CST	Mesoscale Discussion	SPC	Dunklin, Mississippi, New Madrid, Pemiscot	53 min

Nearby

Severe Thunderstorm Watches in Missouri, 2012 Severe Thunderstorm Watches in Kansas, 2012 Every severe thunderstorm watch in 2012

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.