Alert archive / Illinois / Mesoscale Discussions in 2008

Mesoscale Discussion 591

April 8, 200821 counties in Illinois; 7 counties in Indiana

The Storm Prediction Center issued this mesoscale discussion at Apr 8, 2008, 7:58 PM CDT for 21 counties in Illinois; 7 counties in Indiana. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued: Apr 8, 2008, 7:58 PM CDT (00:58 UTC)
Expired: Apr 8, 2008, 9:30 PM CDT
In force: 92 min
Issued by: the Storm Prediction Center

All 28 counties

Bond County, IL, Champaign County, IL, Christian County, IL, Coles County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Fayette County, IL, Ford County, IL, Iroquois County, IL, Logan County, IL, Macon County, IL, Madison County, IL, McLean County, IL, Montgomery County, IL, Moultrie County, IL, Piatt County, IL, Sangamon County, IL, Shelby County, IL, Vermilion County, IL, Benton County, IN, Fountain County, IN, Jasper County, IN, Newton County, IN, Vermillion County, IN, Warren County, IN, White County, IN

The radar

The Lincoln radar (KILX), 77 km from the middle of the area, began a volume at 00:59 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 00:00Z, 1.0 hours before the alert went out and 15 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: 468 J/kg
Mixed-layer CIN: -21 J/kg
Mixed-layer LCL: 771 m above ground
0-6 km bulk shear: 72 kt
0-1 km storm-relative helicity: 398 m²/s²
0-3 km storm-relative helicity: 491 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.8

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
Apr 8, 11:45 PM CDT	Mesoscale Discussion	SPC	Bond, Champaign, Christian, Coles, Cumberland, DeWitt and 15 more	90 min

Nearby

Mesoscale Discussions in Illinois, 2008 Mesoscale Discussions in Indiana, 2008 Every 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.