Alert archive / Missouri / Severe Thunderstorm Watches in 2010
Severe Thunderstorm Watch 366
The Storm Prediction Center issued this severe thunderstorm watch at Jun 21, 2010, 12:58 PM CDT for 27 counties in Illinois; 39 counties in Missouri. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 21, 2010, 12:58 PM CDT (17:58 UTC)
- Expired
- Jun 21, 2010, 4:37 PM CDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 66 counties
Adams County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Christian County, IL, DeWitt County, IL, Fulton County, IL, Greene County, IL, Jersey County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Mason County, IL, McLean County, IL, Menard County, IL, Monroe County, IL, Montgomery County, IL, Morgan County, IL, Peoria County, IL, Pike County, IL, Saint Clair County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Tazewell County, IL, Woodford County, IL, Audrain County, MO, Benton County, MO, Boone County, MO, Callaway County, MO, Carroll County, MO, Chariton County, MO, City of Saint Louis, MO, Cole County, MO, Cooper County, MO, Franklin County, MO, Gasconade County, MO, Henry County, MO, Howard County, MO, Jefferson County, MO, Johnson County, MO, Knox County, MO, Lafayette County, MO, Lewis County, MO, Lincoln County, MO, Linn County, MO, Macon County, MO, Maries County, MO, Marion County, MO, Miller County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Morgan County, MO, Osage County, MO, Pettis County, MO, Pike County, MO, Ralls County, MO, Randolph County, MO, Ray County, MO, Saint Charles County, MO, Saint Louis County, MO, Saline County, MO, Shelby County, MO, Warren County, MO
The radar
The St Louis radar (KLSX), 135 km from the middle of the area, began a volume at 18:00 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
- 10%
- One or more EF2 to EF5 tornadoes
- 2%
- 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
- 70%
Warnings issued inside it
1 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 21, 1:32 PM CDT | Severe Thunderstorm Warning | LSX | Calhoun, Pike | 32 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
Davenport, (KDVN), launched 12:00Z, 6.0 hours before the alert went out and 279 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.
- Mixed-layer CAPE
- 1443 J/kg
- Mixed-layer CIN
- -46 J/kg
- Mixed-layer LCL
- 800 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 34 m²/s²
- 0-3 km storm-relative helicity
- 29 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.7
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 21, 7:39 AM CDT | Mesoscale Discussion | SPC | Adams, Brown, Calhoun, Cass, Greene, Hancock and 6 more | 96 min |
| Jun 21, 12:28 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Calhoun, Cass, Fulton, Greene and 14 more | 62 min |
| Jun 21, 4:10 PM CDT | Mesoscale Discussion | SPC | Adams, Bond, Brown, Calhoun, Cass, Christian and 27 more | 35 min |
| Jun 21, 4:36 PM CDT | Tornado Watch | SPC | Adams, Boone, Brown, Bureau, Cass, Champaign and 42 more | 5 hr |
| Jun 21, 5:35 PM CDT | Mesoscale Discussion | SPC | Clark, Clay, Coles, Crawford, Cumberland, Edgar and 13 more | 55 min |
| Jun 20, 8:07 PM CDT | Severe Thunderstorm Watch | SPC | Andrew, Atchison, Buchanan, Clay, Clinton, DeKalb and 6 more | 6 hr |
| Jun 20, 11:00 PM CDT | Mesoscale Discussion | SPC | Adair, Andrew, Atchison, Buchanan, Caldwell, Carroll and 24 more | 90 min |
| Jun 21, 3:17 AM CDT | Mesoscale Discussion | SPC | Andrew, Atchison, DeKalb, Gentry, Harrison, Holt and 2 more | 58 min |
| Jun 21, 3:45 AM CDT | Severe Thunderstorm Watch | SPC | Atchison, Holt | 5 hr |
| Jun 21, 1:48 PM CDT | Mesoscale Discussion | SPC | Platte | 87 min |
| Jun 21, 5:30 PM CDT | Mesoscale Discussion | SPC | Andrew, Atchison, Buchanan, Clinton, Daviess, DeKalb and 9 more | 90 min |
| Jun 21, 5:56 PM CDT | Severe Thunderstorm Watch | SPC | Adair, Andrew, Atchison, Buchanan, Caldwell, Clinton and 15 more | 7 hr |
Nearby
Severe Thunderstorm Watches in Missouri, 2010Severe Thunderstorm Watches in Illinois, 2010Every severe thunderstorm 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.