Alert archive / Missouri / Mesoscale Discussions in 2011
Mesoscale Discussion 520
The Storm Prediction Center issued this mesoscale discussion at Apr 22, 2011, 5:21 PM CDT for 4 counties in Illinois; 42 counties in Missouri. It was in force for 114 min.
The area
The outline as issued.
The facts
- Issued
- Apr 22, 2011, 5:21 PM CDT (22:21 UTC)
- Expired
- Apr 22, 2011, 7:15 PM CDT
- In force
- 114 min
- Issued by
- the Storm Prediction Center
All 46 counties
Calhoun County, IL, Greene County, IL, Jersey County, IL, Macoupin 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, Dallas County, MO, Dent County, MO, Douglas County, MO, Franklin County, MO, Gasconade County, MO, Greene County, MO, Hickory County, MO, Howell 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, Osage County, MO, Ozark County, MO, Phelps County, MO, Pike County, MO, Polk County, MO, Pulaski County, MO, Saint Charles County, MO, Saint Louis 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 St Louis radar (KLSX), 89 km from the middle of the area, began a volume at 22:21 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.
The watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Springfield, MO (KSGF), launched 12:00Z, 10.4 hours before the alert went out and 250 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
- 148 J/kg
- Mixed-layer CIN
- -391 J/kg
- Mixed-layer LCL
- 454 m above ground
- 0-6 km bulk shear
- 42 kt
- 0-1 km storm-relative helicity
- 516 m²/s²
- 0-3 km storm-relative helicity
- 554 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.1
The text
As transmitted, in the capitals the NWS used until 2016.
243 ACUS11 KWNS 222221 SWOMCD SPC MCD 222221 ILZ000-MOZ000-ARZ000-OKZ000-230015- MESOSCALE DISCUSSION 0520 NWS STORM PREDICTION CENTER NORMAN OK 0521 PM CDT FRI APR 22 2011 AREAS AFFECTED...CNTRL AND ERN MO...WRN IL CONCERNING...TORNADO WATCH 179... VALID 222221Z - 230015Z THE SEVERE WEATHER THREAT FOR TORNADO WATCH 179 CONTINUES. CONDITIONS REMAIN FAVORABLE FOR TORNADOES ACROSS TORNADO WATCH 179...ESPECIALLY OVER CNTRL AND ERN PORTIONS FROM THE COLUMBIA/JEFFERSON CITY/VICHY AREA EWD TOWARDS ST. LOUIS. THE CNW PROFILER AND SGF VWP SHOWS RELATIVELY VEERED FLOW IN THE LOW LEVELS ACROSS WRN MO...WHICH IS RESULTING IN STRAIGHT LINE HODOGRAPHS. HOWEVER..FARTHER NE WHERE SURFACE WINDS ARE MORE BACKED AHEAD OF THE LOW AND IN THE WAKE OF EARLIER CONVECTION...SHEAR IS STRONGER WITH 0-1 KM SRH OVER 300 M2/S2. SUPERCELLS JUST S OF THE COLUMBIA MO AREA HAVE SHOWN STRONG ROTATION...AND THIS TREND IS EXPECTED TO CONTINUE AS THESE CELLS ENCOUNTER GREATER LOW LEVEL SHEAR TO THE E. ISOLATED STRONG TORNADOES MAY OCCUR. LARGE HAIL...SOME VERY LARGE...WILL REMAIN POSSIBLE AREA-WIDE. ..JEWELL.. 04/22/2011 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ILX...LSX...LZK...SGF...EAX...TSA... LAT...LON 39478945 36449212 36459464 39489206 39478945
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 22, 10:09 AM CDT | Mesoscale Discussion | SPC | Alexander, Bond, Calhoun, Clinton, Franklin, Greene and 14 more | 66 min |
| Apr 22, 1:14 PM CDT | Mesoscale Discussion | SPC | Crawford, Edwards, Jasper, Lawrence, Richland, Wabash | 61 min |
| Apr 22, 1:31 PM CDT | Severe Thunderstorm Watch | SPC | Edwards, Franklin, Gallatin, Hamilton, Jefferson, Saline and 4 more | 4 hr |
| Apr 22, 3:34 PM CDT | Tornado Watch | SPC | Calhoun, Greene, Jersey, Macoupin, Madison, Monroe and 2 more | 6 hr |
| Apr 22, 5:27 PM CDT | Mesoscale Discussion | SPC | Clinton, Edwards, Franklin, Gallatin, Hamilton, Hardin and 18 more | 33 min |
| Apr 22, 5:49 PM CDT | Tornado Watch | SPC | Alexander, Bond, Clay, Clinton, Crawford, Edwards and 26 more | 7 hr |
| Apr 21, 11:27 PM CDT | Mesoscale Discussion | SPC | Barton, Bates, Buchanan, Cass, Clay, Jackson and 3 more | 3 hr |
| Apr 22, 2:48 AM CDT | Severe Thunderstorm Watch | SPC | Andrew, Bates, Buchanan, Cass, Clay, Clinton and 4 more | 4 hr |
| Apr 22, 5:18 AM CDT | Mesoscale Discussion | SPC | Buchanan, Caldwell, Cass, Clay, Clinton, Jackson and 2 more | 87 min |
| Apr 22, 10:44 AM CDT | Mesoscale Discussion | SPC | Barry, Bollinger, Carter, Christian, Crawford, Dent and 19 more | 61 min |
| Apr 22, 1:04 PM CDT | Mesoscale Discussion | SPC | Barry, Barton, Benton, Callaway, Camden, Cedar and 40 more | 116 min |
| Apr 22, 1:23 PM CDT | Mesoscale Discussion | SPC | McDonald, Newton | 97 min |
Nearby
Mesoscale Discussions in Missouri, 2011Mesoscale Discussions in Illinois, 2011Every mesoscale discussion 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.