Alert archive / Missouri / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 737

August 7, 201124 counties in Missouri

The Storm Prediction Center issued this severe thunderstorm watch at Aug 7, 2011, 3:29 PM CDT for 24 counties in Missouri. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Aug 7, 2011, 3:29 PM CDT (20:29 UTC)
Expired
Aug 7, 2011, 9:08 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 24 counties

Barton County, MO, Benton County, MO, Boone County, MO, Callaway County, MO, Camden County, MO, Cedar County, MO, Cole County, MO, Crawford County, MO, Dade County, MO, Dallas County, MO, Dent County, MO, Gasconade County, MO, Hickory County, MO, Laclede County, MO, Maries County, MO, Miller County, MO, Moniteau County, MO, Morgan County, MO, Osage County, MO, Phelps County, MO, Polk County, MO, Pulaski County, MO, St. Clair County, MO, Vernon County, MO

The radar

The Springfield radar (KSGF), 119 km from the middle of the area, began a volume at 20:31 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
40%
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
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Aug 7, 4:37 PM CDTSevere Thunderstorm WarningLSXBoone, Callaway, Cole, Moniteau38 min
Aug 7, 4:41 PM CDTSevere Thunderstorm WarningSGFMorgan30 min
Aug 7, 4:46 PM CDTSevere Thunderstorm WarningSGFBenton44 min
Aug 7, 5:09 PM CDTSevere Thunderstorm WarningSGFDallas, Hickory66 min
Aug 7, 5:13 PM CDTSevere Thunderstorm WarningLSXBoone, Callaway, Cole, Moniteau, Osage47 min
Aug 7, 5:14 PM CDTSevere Thunderstorm WarningSGFBarton, Cedar, Vernon20 min
Aug 7, 5:25 PM CDTSevere Thunderstorm WarningSGFBenton, Camden, Morgan65 min
Aug 7, 5:29 PM CDTSevere Thunderstorm WarningSGFDallas, Hickory, Polk61 min
Aug 7, 5:58 PM CDTSevere Thunderstorm WarningLSXCrawford, Franklin, Gasconade, Osage30 min
Aug 7, 5:58 PM CDTSevere Thunderstorm WarningSGFCamden, Miller, Morgan39 min
Aug 7, 6:03 PM CDTSevere Thunderstorm WarningSGFCamden, Dallas, Hickory, Laclede, Polk57 min
Aug 7, 6:27 PM CDTSevere Thunderstorm WarningSGFDallas, Laclede, Webster, Wright63 min
Aug 7, 7:44 PM CDTSevere Thunderstorm WarningSGFDent, Shannon, Texas61 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, 8.5 hours before the alert went out and 167 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, Springfield, MO at 12:00Z on 2011-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1116 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, Springfield, MO at 12:00Z on 2011-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 7 square meters per square second.1939Sfc1 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
1116 J/kg
Mixed-layer CIN
-131 J/kg
Mixed-layer LCL
1673 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
7 m²/s²
0-3 km storm-relative helicity
44 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
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, 10:48 AM CDTMesoscale DiscussionSPCPlatte117 min
Aug 7, 12:55 PM CDTSevere Thunderstorm WatchSPCBates, Buchanan, Caldwell, Carroll, Cass, Clay and 11 more5 hr
Aug 7, 3:16 PM CDTMesoscale DiscussionSPCBarton, Bates, Benton, Camden, Carroll, Cass and 24 more119 min
Aug 7, 5:20 PM CDTMesoscale DiscussionSPCBarry, Barton, Benton, Bollinger, Boone, Callaway and 48 more115 min
Aug 7, 5:41 PM CDTSevere Thunderstorm WatchSPCBollinger, Butler, Cape Girardeau, Carter, Franklin, Iron and 17 more6 hr
Aug 7, 6:07 PM CDTSevere Thunderstorm WatchSPCBarry, Christian, Douglas, Greene, Howell, Jasper and 11 more5 hr

Nearby

Severe Thunderstorm Watches in Missouri, 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.