Alert archive / Illinois / Mesoscale Discussions in 2004
Mesoscale Discussion 2027
The Storm Prediction Center issued this mesoscale discussion at Aug 17, 2004, 3:59 PM CDT for 5 states. It was in force for 61 min.
The area
The outline as issued.
The facts
- Issued
- Aug 17, 2004, 3:59 PM CDT (20:59 UTC)
- Expired
- Aug 17, 2004, 5:00 PM CDT
- In force
- 61 min
- Issued by
- the Storm Prediction Center
All 98 counties
Des Moines County, IA, Henry County, IA, Lee County, IA, Van Buren County, IA, Adams County, IL, Brown County, IL, Bureau County, IL, Calhoun County, IL, Cass County, IL, Champaign County, IL, Cook County, IL, DeKalb County, IL, DeWitt County, IL, DuPage County, IL, Ford County, IL, Fulton County, IL, Greene County, IL, Grundy County, IL, Hancock County, IL, Henderson County, IL, Henry County, IL, Iroquois County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, Knox County, IL, Lake County, IL, LaSalle County, IL, Lee County, IL, Livingston County, IL, Logan County, IL, Macon County, IL, Marshall County, IL, Mason County, IL, McDonough County, IL, McLean County, IL, Menard County, IL, Mercer County, IL, Morgan County, IL, Peoria County, IL, Piatt County, IL, Pike County, IL, Putnam County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Stark County, IL, Tazewell County, IL, Warren County, IL, Will County, IL, Woodford County, IL, Benton County, IN, Carroll County, IN, Cass County, IN, Elkhart County, IN, Fulton County, IN, Jasper County, IN, Kosciusko County, IN, LaGrange County, IN, Lake County, IN, LaPorte County, IN, Marshall County, IN, Miami County, IN, Newton County, IN, Noble County, IN, Porter County, IN, Pulaski County, IN, Saint Joseph County, IN, Starke County, IN, Steuben County, IN, Wabash County, IN, White County, IN, Whitley County, IN, Allegan County, MI, Barry County, MI, Berrien County, MI, Branch County, MI, Calhoun County, MI, Cass County, MI, Eaton County, MI, Hillsdale County, MI, Kalamazoo County, MI, Saint Joseph County, MI, Van Buren County, MI, Audrain County, MO, Callaway County, MO, Clark County, MO, Cole County, MO, Knox County, MO, Lewis County, MO, Lincoln County, MO, Marion County, MO, Monroe County, MO, Montgomery County, MO, Pike County, MO, Ralls County, MO, Scotland County, MO, Shelby County, MO
The radar
The Chicago radar (KLOT), 71 km from the middle of the area, began a volume at 21:03 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, 9.0 hours before the alert went out and 97 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
- 127 J/kg
- Mixed-layer CIN
- -124 J/kg
- Mixed-layer LCL
- 932 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- 103 m²/s²
- 0-3 km storm-relative helicity
- 92 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 |
|---|---|---|---|---|
| Aug 17, 12:57 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Bureau, Calhoun, Carroll, Cass and 38 more | 63 min |
| Aug 17, 1:20 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Brown, Bureau, Calhoun, Cass, Champaign and 41 more | 6 hr |
| Aug 17, 5:57 PM CDT | Mesoscale Discussion | SPC | Calhoun, Cass, Champaign, Christian, DeWitt, Douglas and 19 more | 93 min |
| Aug 17, 5:40 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Allen, Benton, Carroll, Cass, DeKalb and 21 more | 4 hr |
| Aug 16, 8:54 PM CDT | Mesoscale Discussion | SPC | Audubon, Boone, Calhoun, Carroll, Crawford, Dallas and 30 more | 2 hr |
| Aug 17, 5:04 PM CDT | Mesoscale Discussion | SPC | Bates, Cass, Henry, Jackson, Johnson, Lafayette and 1 more | 116 min |
Nearby
Mesoscale Discussions in Illinois, 2004Mesoscale Discussions in Indiana, 2004Mesoscale Discussions in Missouri, 2004Every mesoscale discussion in 2004
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.