Alert archive / Missouri / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 36
The Storm Prediction Center issued this severe thunderstorm watch at Mar 4, 2011, 1:33 PM CST for Calhoun County, Illinois; 48 counties in Missouri. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Mar 4, 2011, 1:33 PM CST (19:33 UTC)
- Expired
- Mar 4, 2011, 7:00 PM CST
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 49 counties
Calhoun County, IL, Audrain County, MO, Barry County, MO, Boone County, MO, Callaway County, MO, Camden County, MO, Christian County, MO, City of Saint Louis, MO, Cole County, MO, Crawford County, MO, Dade County, MO, Dallas County, MO, Dent County, MO, Douglas County, MO, Franklin County, MO, Gasconade County, MO, Greene County, MO, Hickory County, MO, Howell County, MO, Iron County, MO, Jasper County, MO, Jefferson County, MO, Laclede County, MO, Lawrence County, MO, Lincoln County, MO, Maries County, MO, McDonald County, MO, Miller County, MO, Moniteau County, MO, Montgomery County, MO, Morgan County, MO, Newton County, MO, Osage County, MO, Ozark County, MO, Phelps County, MO, Pike County, MO, Polk County, MO, Pulaski County, MO, Reynolds County, MO, Saint Charles County, MO, Saint Louis County, MO, Shannon County, MO, Stone County, MO, Taney County, MO, Texas County, MO, Warren County, MO, Washington County, MO, Webster County, MO, Wright County, MO
The radar
The Springfield radar (KSGF), 144 km from the middle of the area, began a volume at 19:36 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
- 2%
- Ten or more severe wind reports
- 20%
- One or more gusts of 65 knots or more
- 10%
- 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
14 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 4, 2:47 PM CST | Severe Thunderstorm Warning | LSX | Boone | 43 min |
| Mar 4, 3:13 PM CST | Severe Thunderstorm Warning | LSX | Callaway, Cole, Moniteau, Osage | 47 min |
| Mar 4, 3:20 PM CST | Severe Thunderstorm Warning | LSX | Audrain, Boone | 40 min |
| Mar 4, 3:28 PM CST | Severe Thunderstorm Warning | LSX | Audrain, Boone, Callaway, Montgomery | 47 min |
| Mar 4, 3:34 PM CST | Tornado Warning | LSX | Boone, Callaway, Montgomery | 41 min |
| Mar 4, 3:45 PM CST | Severe Thunderstorm Warning | LSX | Audrain, Monroe, Ralls | 45 min |
| Mar 4, 3:49 PM CST | Tornado Warning | LSX | Audrain, Monroe, Pike, Ralls | 56 min |
| Mar 4, 3:59 PM CST | Severe Thunderstorm Warning | LSX | Audrain, Callaway, Franklin, Gasconade, Lincoln, Montgomery and 3 more | 46 min |
| Mar 4, 4:27 PM CST | Tornado Warning | LSX | Lincoln, Montgomery, Warren | 33 min |
| Mar 4, 4:39 PM CST | Severe Thunderstorm Warning | LSX | Calhoun, Greene, Jersey | 51 min |
| Mar 4, 4:40 PM CST | Tornado Warning | LSX | Calhoun, Greene, Pike | 51 min |
| Mar 4, 5:23 PM CST | Severe Thunderstorm Warning | LSX | Calhoun, Jersey, Madison | 29 min |
| Mar 4, 6:20 PM CST | Flash Flood Warning | LSX | Franklin, Saint Charles, Saint Louis, Warren, City of Saint Louis | 5 hr |
| Mar 4, 7:00 PM CST | Severe Thunderstorm Warning | SGF | Laclede, Phelps, Pulaski, Texas | 45 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 12:00Z, 7.6 hours before the alert went out and 195 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
- 18 J/kg
- Mixed-layer CIN
- -209 J/kg
- Mixed-layer LCL
- 1021 m above ground
- 0-6 km bulk shear
- 42 kt
- 0-1 km storm-relative helicity
- 313 m²/s²
- 0-3 km storm-relative helicity
- 299 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 |
|---|---|---|---|---|
| Mar 4, 3:22 PM CST | Mesoscale Discussion | SPC | Calhoun, Cass, Greene, Jersey, Macoupin, Menard and 4 more | 83 min |
| Mar 4, 4:54 PM CST | Tornado Watch | SPC | Bond, Calhoun, Christian, Clay, Clinton, Effingham and 16 more | 118 min |
| Mar 4, 11:52 AM CST | Mesoscale Discussion | SPC | Barry, Barton, Benton, Camden, Cedar, Christian and 15 more | 2 hr |
| Mar 4, 3:55 PM CST | Mesoscale Discussion | SPC | Barry, Cedar, Christian, Dade, Dallas, Douglas and 14 more | 95 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.