Alert archive / Missouri / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 498
The Storm Prediction Center issued this severe thunderstorm watch at Jun 18, 2011, 2:44 AM CDT for 46 counties in Missouri. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 18, 2011, 2:44 AM CDT (07:44 UTC)
- Expired
- Jun 18, 2011, 8:00 AM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 46 counties
Audrain County, MO, Benton County, MO, Boone County, MO, Callaway County, MO, Camden County, MO, Carroll County, MO, Cedar County, MO, Chariton County, MO, City of Saint Louis, MO, Cole County, MO, Cooper County, MO, Crawford County, MO, Dallas County, MO, Dent County, MO, Franklin County, MO, Gasconade County, MO, Hickory County, MO, Howard County, MO, Iron County, MO, Jefferson County, MO, Laclede County, MO, Lincoln County, MO, Madison County, MO, Maries County, MO, Miller County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Morgan County, MO, Osage County, MO, Pettis County, MO, Phelps County, MO, Pike County, MO, Polk County, MO, Pulaski County, MO, Ralls County, MO, Randolph County, MO, Reynolds County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Saline County, MO, St. Clair County, MO, Warren County, MO, Washington County, MO
The radar
The Pleasant Hill radar (KEAX), 114 km from the middle of the area, began a volume at 07:45 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
- 30%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
15 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 18, 2:51 AM CDT | Severe Thunderstorm Warning | SGF | Camden, Morgan | 54 min |
| Jun 18, 2:56 AM CDT | Severe Thunderstorm Warning | EAX | Cooper, Henry, Howard, Johnson, Pettis, Saline | 34 min |
| Jun 18, 3:12 AM CDT | Severe Thunderstorm Warning | LSX | Audrain, Boone, Callaway, Cole, Moniteau, Osage | 63 min |
| Jun 18, 3:28 AM CDT | Severe Thunderstorm Warning | EAX | Chariton, Cooper, Howard, Pettis, Randolph, Saline | 47 min |
| Jun 18, 4:00 AM CDT | Severe Thunderstorm Warning | LSX | Audrain, Callaway, Cole, Gasconade, Montgomery, Osage | 45 min |
| Jun 18, 4:03 AM CDT | Severe Thunderstorm Warning | SGF | Benton, Camden, Hickory | 42 min |
| Jun 18, 4:30 AM CDT | Severe Thunderstorm Warning | LSX | Audrain, Callaway, Franklin, Gasconade, Lincoln, Montgomery and 4 more | 60 min |
| Jun 18, 4:56 AM CDT | Tornado Warning | LSX | Lincoln, Montgomery, Saint Charles, Warren | 49 min |
| Jun 18, 5:07 AM CDT | Tornado Warning | LSX | Lincoln, Montgomery, Pike | 38 min |
| Jun 18, 5:10 AM CDT | Severe Thunderstorm Warning | LSX | Marion, Pike, Ralls | 65 min |
| Jun 18, 5:18 AM CDT | Severe Thunderstorm Warning | LSX | Franklin, Jefferson, Lincoln, Pike, Saint Charles, Saint Louis and 2 more | 57 min |
| Jun 18, 5:30 AM CDT | Tornado Warning | LSX | Lincoln, Pike, Saint Charles | 19 min |
| Jun 18, 5:59 AM CDT | Severe Thunderstorm Warning | SGF | St. Clair, Vernon | 40 min |
| Jun 18, 6:09 AM CDT | Severe Thunderstorm Warning | LSX | Saint Charles, Saint Louis | 51 min |
| Jun 18, 7:28 AM CDT | Severe Thunderstorm Warning | LSX | Madison | 16 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, 7.7 hours before the alert went out and 213 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
- 3544 J/kg
- Mixed-layer CIN
- -1 J/kg
- Mixed-layer LCL
- 1159 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 105 m²/s²
- 0-3 km storm-relative helicity
- 207 m²/s²
- Significant tornado parameter
- 1.3
- Supercell composite
- 8.5
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 17, 8:19 PM CDT | Severe Thunderstorm Watch | SPC | Barton, Bates, Benton, Camden, Carroll, Cass and 24 more | 7 hr |
| Jun 17, 11:12 PM CDT | Mesoscale Discussion | SPC | Barton, Bates, Cass, Cedar, Henry, Jackson and 3 more | 93 min |
| Jun 18, 2:07 AM CDT | Mesoscale Discussion | SPC | Bates, Benton, Buchanan, Caldwell, Camden, Carroll and 21 more | 53 min |
| Jun 18, 5:39 AM CDT | Mesoscale Discussion | SPC | Audrain, Bollinger, Boone, Callaway, Camden, Cape Girardeau and 36 more | 66 min |
| Jun 18, 9:39 AM CDT | Severe Thunderstorm Watch | SPC | Dunklin, Pemiscot | 7 hr |
| Jun 18, 3:34 PM CDT | Mesoscale Discussion | SPC | Barton, Bates, Benton, Cass, Cedar, Dade and 8 more | 116 min |
| Jun 18, 6:03 PM CDT | Severe Thunderstorm Watch | SPC | Barry, Barton, Bates, Benton, Carroll, Cass and 28 more | 10 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.