Alert archive / Illinois / Mesoscale Discussions in 2014

Mesoscale Discussion 1620

August 26, 201412 counties in Illinois; Lake County, Porter County, Indiana; Kenosha County, Walworth County, Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Aug 26, 2014, 9:34 AM CDT for 12 counties in Illinois; Lake County, Porter County, Indiana; Kenosha County, Walworth County, Wisconsin. It was in force for 116 min.

The area

The outline as issued.

The facts

Issued: Aug 26, 2014, 9:34 AM CDT (14:34 UTC)
Expired: Aug 26, 2014, 11:30 AM CDT
In force: 116 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Boone 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, McHenry County, IL, Will County, IL, Lake County, IN, Porter County, IN, Kenosha County, WI, Walworth County, WI

The radar

The Chicago radar (KLOT), 45 km from the middle of the area, began a volume at 14:36 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

Davenport, (KDVN), launched 12:00Z, 2.6 hours before the alert went out and 192 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: 2708 J/kg
Mixed-layer CIN: -58 J/kg
Mixed-layer LCL: 965 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 53 m²/s²
0-3 km storm-relative helicity: 41 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
Aug 25, 7:45 PM CDT	Mesoscale Discussion	SPC	DeKalb, DuPage, Ford, Grundy, Iroquois, Kane and 9 more	60 min
Aug 26, 2:09 PM CDT	Mesoscale Discussion	SPC	Champaign, Clark, Coles, Cumberland, DeWitt, Douglas and 6 more	3 hr
Aug 26, 12:49 PM CDT	Mesoscale Discussion	SPC	Allen, Carroll, Cass, DeKalb, Elkhart, Fulton and 14 more	2 hr

Nearby

Mesoscale Discussions in Illinois, 2014 Mesoscale Discussions in Indiana, 2014 Mesoscale Discussions in Wisconsin, 2014 Every mesoscale discussion in 2014

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.