Alert archive / Missouri / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 294
The Storm Prediction Center issued this severe thunderstorm watch at May 12, 2011, 5:31 PM CDT for 39 counties in Missouri. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- May 12, 2011, 5:31 PM CDT (22:31 UTC)
- Expired
- May 12, 2011, 11:53 PM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 39 counties
Adair County, MO, Audrain County, MO, Bates County, MO, Boone County, MO, Caldwell County, MO, Callaway County, MO, Carroll County, MO, Cass County, MO, Chariton County, MO, Clay County, MO, Clinton County, MO, Cole County, MO, Cooper County, MO, Crawford County, MO, Daviess County, MO, DeKalb County, MO, Franklin County, MO, Gasconade County, MO, Grundy County, MO, Henry County, MO, Howard County, MO, Iron County, MO, Jackson County, MO, Johnson County, MO, Lafayette County, MO, Linn County, MO, Livingston County, MO, Macon County, MO, Moniteau County, MO, Monroe County, MO, Osage County, MO, Pettis County, MO, Randolph County, MO, Ray County, MO, Reynolds County, MO, Saline County, MO, Shelby County, MO, Sullivan County, MO, Washington County, MO
The radar
The Pleasant Hill radar (KEAX), 56 km from the middle of the area, began a volume at 22:31 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
- 30%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 50%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
13 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 12, 5:45 PM CDT | Severe Thunderstorm Warning | EAX | Henry | 30 min |
| May 12, 6:12 PM CDT | Severe Thunderstorm Warning | EAX | Henry, Pettis | 21 min |
| May 12, 6:16 PM CDT | Severe Thunderstorm Warning | EAX | Cooper, Pettis, Saline | 44 min |
| May 12, 6:40 PM CDT | Severe Thunderstorm Warning | LSX | Moniteau | 50 min |
| May 12, 6:54 PM CDT | Severe Thunderstorm Warning | EAX | Cooper | 36 min |
| May 12, 7:43 PM CDT | Severe Thunderstorm Warning | LSX | Boone | 47 min |
| May 12, 7:51 PM CDT | Severe Thunderstorm Warning | LSX | Audrain, Boone, Callaway | 24 min |
| May 12, 7:56 PM CDT | Severe Thunderstorm Warning | LSX | Cole | 49 min |
| May 12, 8:03 PM CDT | Severe Thunderstorm Warning | EAX | Macon, Randolph | 42 min |
| May 12, 8:13 PM CDT | Severe Thunderstorm Warning | LSX | Audrain, Boone, Callaway, Monroe, Shelby | 47 min |
| May 12, 8:41 PM CDT | Severe Thunderstorm Warning | LSX | Knox, Lewis, Shelby | 49 min |
| May 12, 10:04 PM CDT | Severe Thunderstorm Warning | LSX | Crawford, Franklin, Gasconade, Osage | 56 min |
| May 12, 10:50 PM CDT | Severe Thunderstorm Warning | LSX | Crawford, Franklin, Gasconade, Jefferson, Washington | 40 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
Topeka, KS (KTOP), launched 12:00Z, 10.5 hours before the alert went out and 177 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
- 3 J/kg
- Mixed-layer CIN
- -335 J/kg
- Mixed-layer LCL
- 637 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- 57 m²/s²
- 0-3 km storm-relative helicity
- 63 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 11, 8:16 PM CDT | Mesoscale Discussion | SPC | Atchison, Holt, Nodaway | 59 min |
| May 12, 1:46 PM CDT | Mesoscale Discussion | SPC | McDonald, Newton | 119 min |
| May 12, 3:17 PM CDT | Severe Thunderstorm Watch | SPC | Barry, Barton, Benton, Camden, Cedar, Christian and 25 more | 7 hr |
| May 12, 4:54 PM CDT | Mesoscale Discussion | SPC | Bates, Benton, Boone, Buchanan, Caldwell, Camden and 25 more | 66 min |
| May 12, 6:30 PM CDT | Mesoscale Discussion | SPC | Barry, Christian, Douglas, Greene, Jasper, Lawrence and 5 more | 90 min |
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.