Alert archive / Illinois / Mesoscale Discussions in 2018
Mesoscale Discussion 1418
The Storm Prediction Center issued this mesoscale discussion at Sep 3, 2018, 1:20 PM CDT for 28 counties in Illinois; 15 counties in Iowa; 4 counties in Wisconsin. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Sep 3, 2018, 1:20 PM CDT (18:20 UTC)
- Expired
- Sep 3, 2018, 3:45 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 5%
All 47 counties
Cedar County, IA, Clinton County, IA, Des Moines County, IA, Henry County, IA, Iowa County, IA, Jackson County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Linn County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Washington County, IA, Boone County, IL, Bureau County, IL, Carroll County, IL, Cook County, IL, DeKalb County, IL, DuPage County, IL, Grundy County, IL, Henderson County, IL, Henry County, IL, Jo Daviess County, IL, Kane County, IL, Kendall County, IL, Knox County, IL, Lake County, IL, LaSalle County, IL, Lee County, IL, Marshall County, IL, McHenry County, IL, Mercer County, IL, Ogle County, IL, Putnam County, IL, Rock Island County, IL, Stark County, IL, Stephenson County, IL, Warren County, IL, Whiteside County, IL, Will County, IL, Winnebago County, IL, Kenosha County, WI, Racine County, WI, Rock County, WI, Walworth County, WI
The radar
The Quad Cities radar (KDVN), 60 km from the middle of the area, began a volume at 18:19 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 nearest sounding before it
Lincoln, IL (KILX), launched 12:00Z, 6.3 hours before the alert went out and 206 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
- 673 J/kg
- Mixed-layer CIN
- -56 J/kg
- Mixed-layer LCL
- 1242 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 132 m²/s²
- 0-3 km storm-relative helicity
- 128 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 1.7
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 |
|---|---|---|---|---|
| Sep 3, 5:47 PM CDT | Mesoscale Discussion | SPC | Adair, Adams, Benton, Black Hawk, Boone, Bremer and 39 more | 58 min |
| Sep 3, 6:09 PM CDT | Tornado Watch | SPC | Benton, Black Hawk, Buchanan, Delaware, Dubuque, Iowa and 6 more | 2 hr |
Nearby
Mesoscale Discussions in Illinois, 2018Mesoscale Discussions in Iowa, 2018Mesoscale Discussions in Wisconsin, 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.