Alert archive / Missouri / Tornado Watches in 2010

Tornado Watch 451

July 11, 201030 counties in Missouri

The Storm Prediction Center issued this tornado watch at Jul 11, 2010, 12:17 PM CDT for 30 counties in Missouri. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Jul 11, 2010, 12:17 PM CDT (17:17 UTC)
Expired: Jul 11, 2010, 3:39 PM CDT
In force: 3 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2.5 in
Strongest gust expected: 60 kt

All 30 counties

Bates County, MO, Benton County, MO, Boone County, MO, Callaway County, MO, Camden County, MO, Cass County, MO, City of Saint Louis, MO, Cole County, MO, Cooper County, MO, Crawford County, MO, Franklin County, MO, Gasconade County, MO, Henry County, MO, Hickory County, MO, Jefferson County, MO, Johnson County, MO, Maries County, MO, Miller County, MO, Moniteau County, MO, Montgomery County, MO, Morgan County, MO, Osage County, MO, Pettis County, MO, Phelps County, MO, Pulaski County, MO, Saint Charles County, MO, Saint Louis County, MO, St. Clair County, MO, Warren County, MO, Washington County, MO

The radar

The Pleasant Hill radar (KEAX), 115 km from the middle of the area, began a volume at 17:20 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: 40%
One or more hailstones of 2 inches or more: 30%
Six or more combined severe hail and wind reports: 70%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jul 11, 12:53 PM CDT	Severe Thunderstorm Warning	SGF	Benton, Morgan	52 min
Jul 11, 12:55 PM CDT	Severe Thunderstorm Warning	EAX	Bates, Cass	35 min
Jul 11, 1:09 PM CDT	Severe Thunderstorm Warning	EAX	Bates, Cass, Johnson	36 min
Jul 11, 1:31 PM CDT	Severe Thunderstorm Warning	EAX	Bates, Cass, Henry	29 min
Jul 11, 1:36 PM CDT	Severe Thunderstorm Warning	SGF	Morgan	54 min
Jul 11, 1:44 PM CDT	Severe Thunderstorm Warning	EAX	Bates, Cass	16 min
Jul 11, 1:54 PM CDT	Flash Flood Warning	EAX	Johnson, Pettis	4 hr
Jul 11, 1:57 PM CDT	Severe Thunderstorm Warning	EAX	Henry	33 min
Jul 11, 2:10 PM CDT	Severe Thunderstorm Warning	SGF	Benton, St. Clair	50 min
Jul 11, 2:17 PM CDT	Severe Thunderstorm Warning	SGF	Miller, Morgan	58 min
Jul 11, 2:27 PM CDT	Tornado Warning	SGF	Benton, Morgan	34 min
Jul 11, 2:29 PM CDT	Tornado Warning	SGF	Benton	35 min
Jul 11, 2:33 PM CDT	Tornado Warning	SGF	Miller	42 min
Jul 11, 2:41 PM CDT	Flash Flood Warning	SGF	Benton, Camden, Miller, Morgan	6 hr
Jul 11, 2:55 PM CDT	Severe Thunderstorm Warning	SGF	Benton, Camden, Dallas, Hickory, Laclede, Miller and 1 more	50 min
Jul 11, 3:10 PM CDT	Tornado Warning	SGF	Camden	25 min
Jul 11, 3:11 PM CDT	Severe Thunderstorm Warning	EAX	Bates	34 min
Jul 11, 3:17 PM CDT	Severe Thunderstorm Warning	SGF	Maries, Miller	43 min
Jul 11, 3:23 PM CDT	Tornado Warning	SGF	Maries, Miller	39 min
Jul 11, 3:31 PM CDT	Tornado Warning	SGF	Camden, Laclede, Pulaski	44 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

Springfield, MO (KSGF), launched 12:00Z, 5.3 hours before the alert went out and 197 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: 1329 J/kg
Mixed-layer CIN: -18 J/kg
Mixed-layer LCL: 876 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 61 m²/s²
0-3 km storm-relative helicity: 112 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 4.2

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 11, 5:55 AM CDT	Mesoscale Discussion	SPC	Cass, Jackson, Platte	3 hr
Jul 11, 9:40 AM CDT	Mesoscale Discussion	SPC	Barton, Bates, Benton, Bollinger, Butler, Camden and 43 more	95 min
Jul 11, 10:07 AM CDT	Severe Thunderstorm Watch	SPC	Barry, Barton, Bates, Benton, Bollinger, Butler and 53 more	6 hr
Jul 11, 1:11 PM CDT	Mesoscale Discussion	SPC	Dunklin, Pemiscot	94 min
Jul 11, 2:06 PM CDT	Mesoscale Discussion	SPC	Bates, Benton, Boone, Callaway, Camden, Cass and 28 more	54 min
Jul 11, 3:19 PM CDT	Mesoscale Discussion	SPC	Barry, Barton, Bates, Benton, Bollinger, Butler and 58 more	56 min
Jul 11, 3:37 PM CDT	Severe Thunderstorm Watch	SPC	Barry, Barton, Bates, Benton, Bollinger, Butler and 58 more	7 hr
Jul 11, 6:04 PM CDT	Mesoscale Discussion	SPC	Bates, Bollinger, Butler, Cape Girardeau, Carter, Cedar and 30 more	56 min

Nearby

Tornado Watches in Missouri, 2010 Every tornado watch in 2010

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.