Alert archive / Illinois / Mesoscale Discussions in 2016
Mesoscale Discussion 601
The Storm Prediction Center issued this mesoscale discussion at May 11, 2016, 11:20 AM CDT for 17 counties in Illinois; 8 counties in Missouri. It was in force for 55 min.
The area
The outline as issued.
The facts
- Issued
- May 11, 2016, 11:20 AM CDT (16:20 UTC)
- Expired
- May 11, 2016, 12:15 PM CDT
- In force
- 55 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 40%
All 25 counties
Bond County, IL, Calhoun County, IL, Christian County, IL, Clay County, IL, Clinton County, IL, Effingham County, IL, Fayette County, IL, Greene County, IL, Jefferson County, IL, Jersey County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Montgomery County, IL, Saint Clair County, IL, Shelby County, IL, Washington County, IL, City of Saint Louis, MO, Lincoln County, MO, Montgomery County, MO, Pike County, MO, Ralls County, MO, Saint Charles County, MO, Saint Louis County, MO, Warren County, MO
The radar
The St Louis radar (KLSX), 71 km from the middle of the area, began a volume at 16:22 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, 4.3 hours before the alert went out and 169 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 905 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 29 m²/s²
- 0-3 km storm-relative helicity
- 120 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
589 ACUS11 KWNS 111620 SWOMCD SPC MCD 111620 ILZ000-MOZ000-111715- MESOSCALE DISCUSSION 0601 NWS STORM PREDICTION CENTER NORMAN OK 1120 AM CDT WED MAY 11 2016 AREAS AFFECTED...NERN MO...CNTRL IL CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 111620Z - 111715Z PROBABILITY OF WATCH ISSUANCE...40 PERCENT SUMMARY...SEVERE THREAT WILL INCREASE ACROSS NERN MO INTO CNTRL IL THROUGH THE EARLY AFTERNOON. LARGE HAIL AND DAMAGING WINDS ARE THE PRIMARY THREATS. DISCUSSION...OVERNIGHT MCS THAT EVOLVED OVER THE CNTRL PLAINS HAS PROGRESSED INTO THE MID MS VALLEY WITH LARGER PRECIP SHIELD SLOWLY DISSIPATING. HOWEVER...LONE SEVERE TSTM HAS EVOLVED ALONG LEADING EDGE OF THIS ACTIVITY OVER NERN MO AND IS LIKELY PRODUCING LARGE HAIL. THERE IS SOME CONCERN THIS CONVECTION MAY NOT DIE OFF BUT RATHER SLOWLY INCREASE IN AREAL COVERAGE AS IT PROPAGATES EWD INTO IL. 16Z SFC OBS SUGGEST A WELL-DEFINED NW-SE ORIENTED BOUNDARY EXTENDS FROM NEAR STL...SEWD INTO SRN IL. WARM ADVECTION ATOP THIS NWD-ADVANCING BOUNDARY COULD ENCOURAGE ADDITIONAL DEVELOPMENT OVER THE NEXT FEW HOURS...ESPECIALLY GIVEN THAT A WEAK SWLY LLJ IS FORECAST TO IMPINGE ON THIS BOUNDARY. ..DARROW/HART.. 05/11/2016 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...PAH...ILX...LSX... LAT...LON 39599157 39668876 38938814 38198884 38749145 39599157
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 11, 12:10 PM CDT | Severe Thunderstorm Watch | SPC | Bond, Calhoun, Cass, Champaign, Christian, Clark and 48 more | 12 hr |
| May 11, 2:19 PM CDT | Mesoscale Discussion | SPC | Bond, Brown, Calhoun, Cass, Christian, Clark and 33 more | 56 min |
| May 11, 3:39 PM CDT | Mesoscale Discussion | SPC | Lawrence, Wabash | 66 min |
| May 11, 5:30 PM CDT | Mesoscale Discussion | SPC | Gallatin, Hardin | 2 hr |
| May 11, 6:30 PM CDT | Severe Thunderstorm Watch | SPC | Bond, Calhoun, Clinton, Franklin, Gallatin, Greene and 19 more | 7 hr |
| May 11, 2:02 AM CDT | Mesoscale Discussion | SPC | Andrew, Atchison, Bates, Buchanan, Caldwell, Cass and 9 more | 118 min |
| May 11, 3:10 AM CDT | Severe Thunderstorm Watch | SPC | Andrew, Atchison, Bates, Buchanan, Caldwell, Cass and 12 more | 5 hr |
| May 11, 5:34 AM CDT | Mesoscale Discussion | SPC | Andrew, Atchison, Bates, Benton, Buchanan, Caldwell and 28 more | 101 min |
| May 11, 3:07 PM CDT | Mesoscale Discussion | SPC | Audrain, Boone, Callaway, Camden, Christian, Cole and 27 more | 53 min |
Nearby
Mesoscale Discussions in Illinois, 2016Mesoscale Discussions in Missouri, 2016Every mesoscale discussion in 2016
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.