Alert archive / Missouri / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 477

June 15, 201125 counties in Arkansas; Monroe County, Randolph County, Saint Clair County, Illinois; 41 counties in Missouri

The Storm Prediction Center issued this severe thunderstorm watch at Jun 15, 2011, 1:09 AM CDT for 25 counties in Arkansas; Monroe County, Randolph County, Saint Clair County, Illinois; 41 counties in Missouri. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Jun 15, 2011, 1:09 AM CDT (06:09 UTC)
Expired
Jun 15, 2011, 5:20 AM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 69 counties

Baxter County, AR, Boone County, AR, Clay County, AR, Cleburne County, AR, Conway County, AR, Craighead County, AR, Cross County, AR, Faulkner County, AR, Fulton County, AR, Greene County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Lawrence County, AR, Marion County, AR, Newton County, AR, Poinsett County, AR, Pope County, AR, Randolph County, AR, Searcy County, AR, Sharp County, AR, Stone County, AR, Van Buren County, AR, White County, AR, Woodruff County, AR, Monroe County, IL, Randolph County, IL, Saint Clair County, IL, Barry County, MO, Bollinger County, MO, Butler County, MO, Camden County, MO, Carter County, MO, Christian County, MO, Cole County, MO, Crawford County, MO, Dallas County, MO, Dent County, MO, Douglas County, MO, Franklin County, MO, Gasconade County, MO, Greene County, MO, Howell County, MO, Iron County, MO, Jefferson County, MO, Laclede County, MO, Lawrence County, MO, Madison County, MO, Maries County, MO, Miller County, MO, Oregon County, MO, Osage County, MO, Ozark County, MO, Perry County, MO, Phelps County, MO, Polk County, MO, Pulaski County, MO, Reynolds County, MO, Ripley County, MO, Saint Francois County, MO, Sainte Genevieve County, MO, Shannon County, MO, Stone County, MO, Taney County, MO, Texas County, MO, Washington County, MO, Wayne County, MO, Webster County, MO, Wright County, MO

The radar

The Springfield radar (KSGF), 146 km from the middle of the area, began a volume at 06:12 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
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

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

IssuedProductOfficeCountiesLasted
Jun 15, 1:43 AM CDTSevere Thunderstorm WarningSGFCamden, Maries, Miller, Pulaski33 min
Jun 15, 1:55 AM CDTSevere Thunderstorm WarningLZKBaxter, Cleburne, Conway, Pope, Searcy, Stone and 1 more50 min
Jun 15, 3:43 AM CDTSevere Thunderstorm WarningMEGClay, Randolph32 min
Jun 15, 3:59 AM CDTSevere Thunderstorm WarningPAHRipley21 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 00:00Z, 6.2 hours before the alert went out and 161 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 00:00Z on 2011-06-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2959 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 00:00Z on 2011-06-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 205 square meters per square second.19395878Sfc1 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
2959 J/kg
Mixed-layer CIN
-37 J/kg
Mixed-layer LCL
1347 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
205 m²/s²
0-3 km storm-relative helicity
240 m²/s²
Significant tornado parameter
1.7
Supercell composite
14.6

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 15, 12:29 AM CDTMesoscale DiscussionSPCBaxter, Boone, Carroll, Clay, Cleburne, Fulton and 13 more2 hr
Jun 15, 4:24 AM CDTMesoscale DiscussionSPCClay96 min
Jun 15, 10:54 AM CDTMesoscale DiscussionSPCArkansas, Crittenden, Desha, Lee, Mississippi, Monroe and 2 more2 hr
Jun 15, 1:57 PM CDTMesoscale DiscussionSPCClark, Garland, Hempstead, Hot Spring, Howard, Little River and 9 more63 min
Jun 15, 1:55 AM CDTMesoscale DiscussionSPCAdams, Brown, Calhoun, Cass, Christian, DeWitt and 22 more3 hr
Jun 15, 2:13 PM CDTMesoscale DiscussionSPCAlexander, Clay, Clinton, Cumberland, DeWitt, Edwards and 27 more2 hr
Jun 14, 7:47 PM CDTMesoscale DiscussionSPCAdair, Andrew, Audrain, Bates, Benton, Boone and 43 more58 min
Jun 14, 8:54 PM CDTMesoscale DiscussionSPCNewton66 min
Jun 14, 9:11 PM CDTMesoscale DiscussionSPCBarry, Barton, Camden, Cedar, Christian, Dade and 23 more64 min

Nearby

Severe Thunderstorm Watches in Missouri, 2011Severe Thunderstorm Watches in Arkansas, 2011Severe Thunderstorm Watches in Illinois, 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.