Alert archive / Illinois / Mesoscale Discussions in 2003
Mesoscale Discussion 1870
The Storm Prediction Center issued this mesoscale discussion at Jul 17, 2003, 6:42 PM CDT for 25 counties in Illinois; 24 counties in Iowa; 4 counties in Wisconsin. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 17, 2003, 6:42 PM CDT (23:42 UTC)
- Expired
- Jul 17, 2003, 8:45 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 53 counties
Benton County, IA, Black Hawk County, IA, Buchanan County, IA, Cedar County, IA, Clayton County, IA, Clinton County, IA, Delaware County, IA, Des Moines County, IA, Dubuque County, IA, Fayette 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, Poweshiek County, IA, Scott County, IA, Tama County, IA, Washington County, IA, Boone County, IL, Bureau County, IL, Carroll County, IL, DeKalb County, IL, Grundy County, IL, Henderson County, IL, Henry County, IL, Jo Daviess County, IL, Kane County, IL, Kendall County, IL, Knox County, IL, LaSalle County, IL, Lee County, IL, Marshall County, IL, Mercer County, IL, Ogle County, IL, Peoria County, IL, Putnam County, IL, Rock Island County, IL, Stark County, IL, Stephenson County, IL, Warren County, IL, Whiteside County, IL, Winnebago County, IL, Woodford County, IL, Grant County, WI, Green County, WI, Lafayette County, WI, Rock County, WI
The radar
The Quad Cities radar (KDVN), 31 km from the middle of the area, began a volume at 23:43 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, 11.7 hours before the alert went out and 262 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
- 27 J/kg
- Mixed-layer CIN
- -504 J/kg
- Mixed-layer LCL
- 1285 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 54 m²/s²
- 0-3 km storm-relative helicity
- 71 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
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 |
|---|---|---|---|---|
| Jul 17, 1:29 PM CDT | Mesoscale Discussion | SPC | Boone, Carroll, Cook, DeKalb, DuPage, Jo Daviess and 6 more | 91 min |
| Jul 16, 10:44 PM CDT | Mesoscale Discussion | SPC | Appanoose, Clarke, Davis, Decatur, Jefferson, Lucas and 10 more | 2 hr |
Nearby
Mesoscale Discussions in Illinois, 2003Mesoscale Discussions in Iowa, 2003Mesoscale Discussions in Wisconsin, 2003Every mesoscale discussion in 2003
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.