Alert archive / Illinois / Mesoscale Discussions in 2004

Mesoscale Discussion 2125

August 26, 200414 counties in Illinois; Lake County, Indiana; Kenosha County, Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Aug 26, 2004, 11:53 PM CDT for 14 counties in Illinois; Lake County, Indiana; Kenosha County, Wisconsin. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued: Aug 26, 2004, 11:53 PM CDT (04:53 UTC)
Expired: Aug 27, 2004, 1:30 AM CDT
In force: 97 min
Issued by: the Storm Prediction Center

Counties Bureau County, IL, Cook County, IL, DeKalb County, IL, DuPage County, IL, Grundy County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, Lake County, IL, LaSalle County, IL, Lee County, IL, McHenry County, IL, Putnam County, IL, Will County, IL, Lake County, IN, Kenosha County, WI

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Severe Thunderstorm Watch 790Aug 27, 1:25 AM CDT

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 4.9 hours before the alert went out and 180 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 3587 J/kg
Mixed-layer CIN: -9 J/kg
Mixed-layer LCL: 948 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 132 m²/s²
0-3 km storm-relative helicity: 211 m²/s²
Significant tornado parameter: 3.5
Supercell composite: 18.5

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 26, 9:13 PM CDT	Mesoscale Discussion	SPC	Carroll, Jo Daviess, Rock Island, Stephenson	62 min
Aug 26, 9:45 PM CDT	Severe Thunderstorm Watch	SPC	Boone, Carroll, Henderson, Henry, Jo Daviess, Mercer and 5 more	6 hr
Aug 27, 1:25 AM CDT	Severe Thunderstorm Watch	SPC	Boone, Bureau, Cook, DeKalb, DeWitt, DuPage and 25 more	6 hr
Aug 27, 1:49 AM CDT	Mesoscale Discussion	SPC	Henderson, Henry, Mercer, Ogle, Rock Island, Whiteside and 1 more	56 min
Aug 27, 4:36 AM CDT	Mesoscale Discussion	SPC	Cook, DeWitt, Ford, Fulton, Grundy, Hancock and 11 more	84 min
Aug 27, 6:33 AM CDT	Mesoscale Discussion	SPC	Champaign, DeWitt, Ford, Iroquois, McLean, Mason and 4 more	27 min
Aug 27, 9:24 AM CDT	Mesoscale Discussion	SPC	Calhoun, Greene, Jersey, Macoupin, Madison, Morgan and 2 more	96 min
Aug 27, 9:40 AM CDT	Severe Thunderstorm Watch	SPC	Brown, Calhoun, Cass, Greene, Jersey, Macoupin and 7 more	5 hr
Aug 27, 1:07 PM CDT	Mesoscale Discussion	SPC	Adams, Bond, Brown, Calhoun, Greene, Jersey and 6 more	113 min
Aug 27, 2:45 PM CDT	Severe Thunderstorm Watch	SPC	Calhoun, Cass, Greene, Jersey, Morgan, Pike and 1 more	6 hr
Aug 27, 3:49 PM CDT	Mesoscale Discussion	SPC	Calhoun, Cass, Greene, Jersey, Morgan, Pike and 1 more	86 min
Aug 27, 4:10 PM CDT	Mesoscale Discussion	SPC	Adams, Brown, Bureau, Fulton, Hancock, Henderson and 14 more	2 hr
Aug 27, 12:10 PM CDT	Mesoscale Discussion	SPC	Adams, Allen, Blackford, Carroll, Cass, DeKalb and 8 more	3 hr
Aug 26, 7:45 PM CDT	Mesoscale Discussion	SPC	Columbia, Crawford, Grant, Green Lake, Iowa, La Crosse and 4 more	90 min

Nearby

Mesoscale Discussions in Illinois, 2004 Mesoscale Discussions in Indiana, 2004 Mesoscale Discussions in Wisconsin, 2004 Every 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.