Alert archive / Illinois / Mesoscale Discussions in 2008
Mesoscale Discussion 2256
The Storm Prediction Center issued this mesoscale discussion at Sep 12, 2008, 11:44 PM CDT for 15 counties in Illinois; 7 counties in Indiana. It was in force for 91 min.
The area
The outline as issued.
The facts
- Issued
- Sep 12, 2008, 11:44 PM CDT (04:44 UTC)
- Expired
- Sep 13, 2008, 1:15 AM CDT
- In force
- 91 min
- Issued by
- the Storm Prediction Center
All 22 counties
Ford County, IL, Grundy County, IL, Iroquois County, IL, Kankakee County, IL, Knox County, IL, LaSalle County, IL, Livingston County, IL, Marshall County, IL, McLean County, IL, Peoria County, IL, Putnam County, IL, Stark County, IL, Warren County, IL, Will County, IL, Woodford County, IL, Benton County, IN, Carroll County, IN, Jasper County, IN, Newton County, IN, Pulaski County, IN, Starke County, IN, White County, IN
The radar
The Chicago radar (KLOT), 91 km from the middle of the area, began a volume at 04:47 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 00:00Z, 4.7 hours before the alert went out and 95 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
- 197 J/kg
- Mixed-layer CIN
- -60 J/kg
- Mixed-layer LCL
- 604 m above ground
- 0-6 km bulk shear
- 49 kt
- 0-1 km storm-relative helicity
- 156 m²/s²
- 0-3 km storm-relative helicity
- 231 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
The text
As transmitted, in the capitals the NWS used until 2016.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 13, 1:29 AM CDT | Mesoscale Discussion | SPC | Ford, Grundy, Iroquois, Kankakee, Kendall, LaSalle and 2 more | 91 min |
| Sep 13, 1:46 AM CDT | Tornado Watch | SPC | Cook, DeKalb, DuPage, Ford, Grundy, Iroquois and 7 more | 6 hr |
| Sep 13, 3:28 AM CDT | Mesoscale Discussion | SPC | Cook, DeKalb, DuPage, Ford, Grundy, Iroquois and 11 more | 92 min |
| Sep 13, 5:27 PM CDT | Mesoscale Discussion | SPC | Brown, Calhoun, Cass, Christian, DeWitt, Greene and 13 more | 2 hr |
| Sep 13, 2:28 PM CDT | Mesoscale Discussion | SPC | DeKalb, Elkhart, Kosciusko, LaGrange, LaPorte, Marshall and 5 more | 2 hr |
Nearby
Mesoscale Discussions in Illinois, 2008Mesoscale Discussions in Indiana, 2008Every mesoscale discussion in 2008
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.