Alert archive / Missouri / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 790
The Storm Prediction Center issued this severe thunderstorm watch at Aug 19, 2011, 1:08 AM CDT for 11 counties in Missouri. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 19, 2011, 1:08 AM CDT (06:08 UTC)
- Expired
- Aug 19, 2011, 5:00 AM CDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 65 kt
Counties Cole County, MO, Crawford County, MO, Franklin County, MO, Gasconade County, MO, Iron County, MO, Madison County, MO, Moniteau County, MO, Osage County, MO, Reynolds County, MO, Saint Francois County, MO, Washington County, MO
The radar
The St Louis radar (KLSX), 102 km from the middle of the area, began a volume at 06:08 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
- 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
3 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 19, 1:14 AM CDT | Severe Thunderstorm Warning | LSX | Boone, Moniteau | 46 min |
| Aug 19, 2:01 AM CDT | Severe Thunderstorm Warning | LSX | Boone, Callaway, Cole, Moniteau, Osage | 44 min |
| Aug 19, 2:34 AM CDT | Severe Thunderstorm Warning | LSX | Callaway, Cole, Crawford, Franklin, Gasconade, Montgomery and 2 more | 41 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, 6.1 hours before the alert went out and 238 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
- 3816 J/kg
- Mixed-layer CIN
- -10 J/kg
- Mixed-layer LCL
- 1273 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 48 m²/s²
- 0-3 km storm-relative helicity
- 180 m²/s²
- Significant tornado parameter
- 1.6
- Supercell composite
- 11.7
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 18, 8:09 PM CDT | Severe Thunderstorm Watch | SPC | Bates, Benton, Buchanan, Caldwell, Camden, Carroll and 18 more | 7 hr |
| Aug 18, 8:29 PM CDT | Mesoscale Discussion | SPC | Andrew, Atchison, DeKalb, Gentry, Holt, Nodaway and 1 more | 61 min |
| Aug 18, 9:52 PM CDT | Mesoscale Discussion | SPC | Andrew, Atchison, Daviess, DeKalb, Gentry, Harrison and 3 more | 53 min |
| Aug 18, 11:46 PM CDT | Mesoscale Discussion | SPC | Barry, Barton, Bates, Benton, Buchanan, Caldwell and 40 more | 59 min |
| Aug 19, 12:02 AM CDT | Severe Thunderstorm Watch | SPC | Barry, Barton, Benton, Camden, Cedar, Christian and 28 more | 5 hr |
| Aug 19, 1:38 AM CDT | Mesoscale Discussion | SPC | Barry, Barton, Benton, Camden, Cedar, Christian and 36 more | 67 min |
| Aug 19, 4:08 AM CDT | Mesoscale Discussion | SPC | Barry, Camden, Christian, Crawford, Dallas, Dent and 22 more | 67 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.