Alert archive / Illinois / Mesoscale Discussions in 2016

Mesoscale Discussion 1352

July 21, 201621 counties in Illinois; Lake County, Porter County, Indiana; 16 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Jul 21, 2016, 8:17 PM CDT for 21 counties in Illinois; Lake County, Porter County, Indiana; 16 counties in Wisconsin. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued: Jul 21, 2016, 8:17 PM CDT (01:17 UTC)
Expired: Jul 21, 2016, 9:15 PM CDT
In force: 58 min
Issued by: the Storm Prediction Center

All 39 counties

Boone County, IL, Bureau County, IL, Carroll County, IL, Cook County, IL, DeKalb County, IL, DuPage County, IL, Grundy County, IL, Jo Daviess County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, Lake County, IL, LaSalle County, IL, Lee County, IL, McHenry County, IL, Ogle County, IL, Putnam County, IL, Stephenson County, IL, Whiteside County, IL, Will County, IL, Winnebago County, IL, Lake County, IN, Porter County, IN, Crawford County, WI, Dane County, WI, Grant County, WI, Green County, WI, Iowa County, WI, Jefferson County, WI, Kenosha County, WI, Lafayette County, WI, Milwaukee County, WI, Racine County, WI, Richland County, WI, Rock County, WI, Sauk County, WI, Vernon County, WI, Walworth County, WI, Waukesha County, WI

The radar

The Milwaukee radar (KMKX), 77 km from the middle of the area, began a volume at 01:17 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 00:00Z, 1.3 hours before the alert went out and 143 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: 4571 J/kg
Mixed-layer CIN: -11 J/kg
Mixed-layer LCL: 1083 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 123 m²/s²
0-3 km storm-relative helicity: 195 m²/s²
Significant tornado parameter: 2.4
Supercell composite: 17.9

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 21, 11:08 PM CDT	Mesoscale Discussion	SPC	Adams, Brown, Cass, Champaign, DeWitt, Ford and 27 more	67 min

Nearby

Mesoscale Discussions in Illinois, 2016 Mesoscale Discussions in Wisconsin, 2016 Mesoscale Discussions in Indiana, 2016 Every mesoscale discussion in 2016

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.