Alert archive / Illinois / Mesoscale Discussions in 2011
Mesoscale Discussion 736
The Storm Prediction Center issued this mesoscale discussion at May 11, 2011, 2:18 PM CDT for 36 counties in Illinois; 5 counties in Missouri. It was in force for 57 min.
The area
The outline as issued.
The facts
- Issued
- May 11, 2011, 2:18 PM CDT (19:18 UTC)
- Expired
- May 11, 2011, 3:15 PM CDT
- In force
- 57 min
- Issued by
- the Storm Prediction Center
All 41 counties
Adams County, IL, Bond County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Champaign County, IL, Christian County, IL, Clinton County, IL, DeWitt County, IL, Douglas County, IL, Effingham County, IL, Fayette County, IL, Ford County, IL, Greene County, IL, Jersey County, IL, Livingston County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Mason County, IL, McLean County, IL, Menard County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Piatt County, IL, Pike County, IL, Saint Clair County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Shelby County, IL, Tazewell County, IL, Woodford County, IL, City of Saint Louis, MO, Lincoln County, MO, Pike County, MO, Saint Charles County, MO, Saint Louis County, MO
The radar
The Lincoln radar (KILX), 56 km from the middle of the area, began a volume at 19:20 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
Lincoln, IL (KILX), launched 12:00Z, 7.3 hours before the alert went out and 105 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
- 2360 J/kg
- Mixed-layer CIN
- -220 J/kg
- Mixed-layer LCL
- 875 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- -68 m²/s²
- 0-3 km storm-relative helicity
- -51 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
443
ACUS11 KWNS 111919
SWOMCD
SPC MCD 111918
ILZ000-MOZ000-112015-
MESOSCALE DISCUSSION 0736
NWS STORM PREDICTION CENTER NORMAN OK
0218 PM CDT WED MAY 11 2011
AREAS AFFECTED...CNTRL IL...FAR ERN MO
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 111918Z - 112015Z
THE THREAT FOR SVR STORMS WITH DMGG WINDS AND LARGE HAIL IS
INCREASING. A SVR TSTM WATCH MAY BE REQUIRED SOUTH OF WW 281...OR WW
281 MAY NEED TO BE EXPANDED SWD.
THE IMPACTS OF A SUBTLE MID-LEVEL IMPULSE SWINGING THROUGH THE
MID-MISSISSIPPI VALLEY REGION CONTINUE TO BE MANIFESTED AS
CONVECTION DEVELOPING NEAR AND NORTH OF THE SAINT LOUIS AREA. MLCAPE
VALUES AOA 2500 J/KG WILL RESULT IN DEEP/VIGOROUS UPDRAFTS. SWLY
FLOW AROUND 50 KT AT 5 KM AGL PER STL VWP...LIKELY ASSOCIATED WITH
THE IMPULSE...WILL PROVIDE SOME SUSTENANCE TO THE MULTICELLULAR
CONVECTION GIVEN EFFECTIVE BULK SHEAR MAGNITUDE VALUES OF 30-35 KT.
DMGG WINDS AND LARGE HAIL WILL BE THE PRIMARY THREATS.
..COHEN.. 05/11/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...LOT...ILX...LSX...DVN...
LAT...LON 38639077 39359146 40159127 40309012 41068920 41058860
40818797 39938815 38728867 38348966 38639077SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 11, 12:55 PM CDT | Mesoscale Discussion | SPC | Boone, Carroll, DeKalb, DuPage, Jo Daviess, Kane and 7 more | 65 min |
| May 11, 1:23 PM CDT | Severe Thunderstorm Watch | SPC | Boone, Bureau, Carroll, Cass, DeKalb, DeWitt and 33 more | 6 hr |
| May 11, 3:38 PM CDT | Mesoscale Discussion | SPC | Boone, Brown, Bureau, Carroll, Cass, Christian and 40 more | 2 hr |
| May 11, 5:56 PM CDT | Severe Thunderstorm Watch | SPC | Boone, Cook, DeKalb, DuPage, Ford, Grundy and 12 more | 5 hr |
| May 11, 8:09 AM CDT | Mesoscale Discussion | SPC | Adair, Grundy, Knox, Linn, Macon, Mercer and 4 more | 66 min |
| May 11, 3:57 PM CDT | Mesoscale Discussion | SPC | Andrew, Atchison, Barton, Bates, Benton, Buchanan and 27 more | 48 min |
| May 11, 4:00 PM CDT | Severe Thunderstorm Watch | SPC | Andrew, Atchison, Barry, Barton, Bates, Buchanan and 35 more | 8 hr |
| May 11, 6:17 PM CDT | Mesoscale Discussion | SPC | Adair, Grundy, Knox, Macon, Mercer, Putnam and 3 more | 28 min |
| May 11, 6:35 PM CDT | Mesoscale Discussion | SPC | Barry, Christian, Dade, Greene, Jasper, Lawrence and 4 more | 55 min |
Nearby
Mesoscale Discussions in Illinois, 2011Mesoscale Discussions in Missouri, 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.