Alert archive / Illinois / Mesoscale Discussions in 2018
Mesoscale Discussion 1684
The Storm Prediction Center issued this mesoscale discussion at Dec 1, 2018, 1:48 PM CST for 32 counties in Illinois; Pike County, Saint Louis County, City of Saint Louis, Missouri. It was in force for 117 min.
The area
The outline as issued.
The facts
- Issued
- Dec 1, 2018, 1:48 PM CST (19:48 UTC)
- Expired
- Dec 1, 2018, 3:45 PM CST
- In force
- 117 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 60%
All 35 counties
Adams County, IL, Bond County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Christian County, IL, Clinton County, IL, DeWitt County, IL, Fayette County, IL, Fulton County, IL, Greene County, IL, Jersey County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Mason County, IL, McDonough County, IL, Menard County, IL, Monroe County, IL, Montgomery County, IL, Morgan County, IL, Peoria County, IL, Pike County, IL, Saint Clair County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Shelby County, IL, Tazewell County, IL, Washington County, IL, City of Saint Louis, MO, Pike County, MO, Saint Louis County, MO
The radar
The Lincoln radar (KILX), 83 km from the middle of the area, began a volume at 19:51 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, 7.8 hours before the alert went out and 130 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
- 430 m above ground
- 0-6 km bulk shear
- 75 kt
- 0-1 km storm-relative helicity
- 529 m²/s²
- 0-3 km storm-relative helicity
- 658 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 1, 2:16 PM CST | Tornado Watch | SPC | Adams, Brown, Calhoun, Cass, Christian, DeWitt and 23 more | 7 hr |
| Dec 1, 5:17 PM CST | Mesoscale Discussion | SPC | Cass, Christian, DeWitt, Ford, Fulton, Knox and 17 more | 88 min |
| Nov 30, 9:12 PM CST | Mesoscale Discussion | SPC | Barry, Barton, Christian, Dade, Douglas, Greene and 6 more | 2 hr |
| Nov 30, 9:47 PM CST | Tornado Watch | SPC | Barry, Barton, Cedar, Christian, Dade, Dallas and 19 more | 5 hr |
| Nov 30, 11:20 PM CST | Mesoscale Discussion | SPC | Barry, Barton, Cedar, Christian, Dade, Greene and 8 more | 85 min |
| Dec 1, 12:58 AM CST | Mesoscale Discussion | SPC | Carter, Christian, Douglas, Greene, Howell, Oregon and 9 more | 2 hr |
| Dec 1, 3:25 AM CST | Mesoscale Discussion | SPC | Dunklin, Pemiscot | 2 hr |
Nearby
Mesoscale Discussions in Illinois, 2018Mesoscale Discussions in Missouri, 2018Every mesoscale discussion in 2018
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.