Alert archive / Missouri / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 359
The Storm Prediction Center issued this severe thunderstorm watch at May 24, 2011, 1:38 PM CDT for 10 counties in Illinois; 33 counties in Missouri. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- May 24, 2011, 1:38 PM CDT (18:38 UTC)
- Expired
- May 24, 2011, 6:51 PM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 43 counties
Adams County, IL, Brown County, IL, Calhoun County, IL, Greene County, IL, Jersey County, IL, Macoupin County, IL, Madison County, IL, Monroe County, IL, Pike County, IL, Saint Clair County, IL, Audrain 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, Howard County, MO, Jefferson County, MO, Knox County, MO, Lafayette County, MO, Lewis County, MO, Lincoln County, MO, Linn County, MO, Livingston County, MO, Macon County, MO, Marion County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Osage County, MO, Pettis County, MO, Pike County, MO, Ralls County, MO, Randolph 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), 167 km from the middle of the area, began a volume at 18:21 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
- 60%
- 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
- 80%
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 |
|---|---|---|---|---|
| May 24, 1:43 PM CDT | Severe Thunderstorm Warning | EAX | Carroll, Chariton, Johnson, Lafayette, Pettis, Ray and 1 more | 47 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, 6.6 hours before the alert went out and 275 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
- 206 J/kg
- Mixed-layer CIN
- -87 J/kg
- Mixed-layer LCL
- 1287 m above ground
- 0-6 km bulk shear
- 28 kt
- 0-1 km storm-relative helicity
- 8 m²/s²
- 0-3 km storm-relative helicity
- 34 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 24, 1:11 PM CDT | Mesoscale Discussion | SPC | Bureau, Ford, Grundy, Henry, Iroquois, Kankakee and 12 more | 94 min |
| May 24, 4:55 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Calhoun, Greene, Jersey, Macoupin and 5 more | 65 min |
| May 24, 9:18 AM CDT | Mesoscale Discussion | SPC | Bates, Cass, Jackson, Vernon | 87 min |
| May 24, 1:35 PM CDT | Mesoscale Discussion | SPC | Audrain, Boone, Caldwell, Callaway, Carroll, Chariton and 24 more | 25 min |
Nearby
Severe Thunderstorm Watches in Missouri, 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.