Alert archive / Illinois / Mesoscale Discussions in 2017

Mesoscale Discussion 1178

June 28, 20177 counties in Illinois; 5 counties in Iowa; 6 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Jun 28, 2017, 7:53 PM CDT for 7 counties in Illinois; 5 counties in Iowa; 6 counties in Wisconsin. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued: Jun 28, 2017, 7:53 PM CDT (00:53 UTC)
Expired: Jun 28, 2017, 9:30 PM CDT
In force: 97 min
Issued by: the Storm Prediction Center

Counties Clinton County, IA, Dubuque County, IA, Jackson County, IA, Jones County, IA, Linn County, IA, Boone County, IL, Carroll County, IL, Jo Daviess County, IL, McHenry County, IL, Ogle County, IL, Stephenson County, IL, Winnebago County, IL, Green County, WI, Jefferson County, WI, Lafayette County, WI, Rock County, WI, Walworth County, WI, Waukesha County, WI

The radar

The Quad Cities radar (KDVN), 94 km from the middle of the area, began a volume at 00:53 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, 0.9 hours before the alert went out and 91 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: 1521 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 1099 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 259 m²/s²
0-3 km storm-relative helicity: 334 m²/s²
Significant tornado parameter: 2.7
Supercell composite: 15.1

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
Jun 28, 7:06 PM CDT	Tornado Watch	SPC	Boone, Cook, DeKalb, DuPage, Kane, Lake and 3 more	4 hr
Jun 29, 1:45 PM CDT	Mesoscale Discussion	SPC	Bond, Calhoun, Christian, Greene, Jersey, Macoupin and 8 more	2 hr
Jun 28, 8:39 PM CDT	Mesoscale Discussion	SPC	Decatur, Ringgold, Taylor	96 min
Jun 29, 2:26 PM CDT	Mesoscale Discussion	SPC	Plymouth	94 min
Jun 29, 3:42 PM CDT	Severe Thunderstorm Watch	SPC	Audubon, Buena Vista, Calhoun, Carroll, Cass, Cherokee and 18 more	8 hr
Jun 29, 3:48 PM CDT	Mesoscale Discussion	SPC	Black Hawk, Bremer, Buchanan, Butler, Clayton, Delaware and 7 more	117 min
Jun 29, 6:08 PM CDT	Mesoscale Discussion	SPC	Audubon, Buena Vista, Carroll, Cass, Cherokee, Clay and 13 more	67 min
Jun 28, 7:20 PM CDT	Mesoscale Discussion	SPC	Barron, Buffalo, Chippewa, Clark, Dunn, Eau Claire and 10 more	115 min

Nearby

Mesoscale Discussions in Illinois, 2017 Mesoscale Discussions in Wisconsin, 2017 Mesoscale Discussions in Iowa, 2017 Every mesoscale discussion in 2017

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.