Alert archive / Illinois / Mesoscale Discussions in 2015

Mesoscale Discussion 2033

December 23, 201511 counties in Illinois; Lake County, Newton County, Indiana; Kenosha County, Milwaukee County, Racine County, Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Dec 23, 2015, 9:41 AM CST for 11 counties in Illinois; Lake County, Newton County, Indiana; Kenosha County, Milwaukee County, Racine County, Wisconsin. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Dec 23, 2015, 9:41 AM CST (15:41 UTC)
Expired: Dec 23, 2015, 11:45 AM CST
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Cook County, IL, DuPage County, IL, Ford County, IL, Grundy County, IL, Iroquois County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, Lake County, IL, Livingston County, IL, Will County, IL, Lake County, IN, Newton County, IN, Kenosha County, WI, Milwaukee County, WI, Racine County, WI

The radar

The Chicago radar (KLOT), 13 km from the middle of the area, began a volume at 15:45 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 12:00Z, 3.7 hours before the alert went out and 156 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: 12 J/kg
Mixed-layer CIN: -75 J/kg
Mixed-layer LCL: 465 m above ground
0-6 km bulk shear: 67 kt
0-1 km storm-relative helicity: 260 m²/s²
0-3 km storm-relative helicity: 212 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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
Dec 23, 6:13 AM CST	Mesoscale Discussion	SPC	Alexander, Bond, Clinton, Franklin, Gallatin, Hamilton and 17 more	2 hr
Dec 23, 9:05 AM CST	Mesoscale Discussion	SPC	Alexander, Clay, Edwards, Franklin, Gallatin, Hamilton and 20 more	85 min
Dec 23, 9:13 AM CST	Tornado Watch	SPC	Alexander, Bond, Champaign, Christian, Clark, Clay and 38 more	8 hr
Dec 23, 10:29 AM CST	Mesoscale Discussion	SPC	Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 15 more	91 min
Dec 23, 12:06 PM CST	Mesoscale Discussion	SPC	Clay, Crawford, Edwards, Gallatin, Hamilton, Hardin and 7 more	84 min
Dec 23, 12:42 PM CST	Mesoscale Discussion	SPC	Adams, Brown, Bureau, Calhoun, Cass, Fulton and 25 more	2 hr
Dec 23, 1:55 PM CST	Tornado Watch	SPC	Adams, Brown, Bureau, Calhoun, Cass, Fulton and 24 more	4 hr
Dec 23, 3:24 PM CST	Mesoscale Discussion	SPC	Adams, Brown, Bureau, Calhoun, Cass, Fulton and 26 more	96 min
Dec 23, 12:28 PM CST	Tornado Watch	SPC	Bartholomew, Boone, Brown, Carroll, Clark, Clay and 51 more	8 hr
Dec 23, 1:55 PM CST	Mesoscale Discussion	SPC	Allen, DeKalb, Elkhart, Huntington, Kosciusko, LaGrange and 4 more	95 min
Dec 23, 2:16 PM CST	Mesoscale Discussion	SPC	Bartholomew, Brown, Clark, Crawford, Dearborn, Decatur and 34 more	59 min
Dec 23, 4:59 PM CST	Mesoscale Discussion	SPC	Clark, Crawford, Dubois, Floyd, Harrison, Orange and 4 more	2 hr

Nearby

Mesoscale Discussions in Illinois, 2015 Mesoscale Discussions in Wisconsin, 2015 Mesoscale Discussions in Indiana, 2015 Every mesoscale discussion in 2015

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.