Alert archive / Illinois / Mesoscale Discussions in 2015

Mesoscale Discussion 1394

July 13, 201535 counties in Illinois; Clinton County, Iowa; 4 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Jul 13, 2015, 3:21 PM CDT for 35 counties in Illinois; Clinton County, Iowa; 4 counties in Wisconsin. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued: Jul 13, 2015, 3:21 PM CDT (20:21 UTC)
Expired: Jul 13, 2015, 4:45 PM CDT
In force: 84 min
Issued by: the Storm Prediction Center
Chance of a watch: 95%

All 40 counties

Clinton County, IA, Boone County, IL, Bureau County, IL, Carroll County, IL, Champaign County, IL, DeKalb County, IL, DeWitt County, IL, Douglas County, IL, DuPage County, IL, Ford County, IL, Grundy County, IL, Henry County, IL, Iroquois County, IL, Jo Daviess County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, Knox County, IL, LaSalle County, IL, Lee County, IL, Livingston County, IL, Logan County, IL, Marshall County, IL, McHenry County, IL, McLean County, IL, Ogle County, IL, Peoria County, IL, Piatt County, IL, Putnam County, IL, Stark County, IL, Stephenson County, IL, Tazewell County, IL, Whiteside County, IL, Will County, IL, Winnebago County, IL, Woodford County, IL, Green County, WI, Lafayette County, WI, Rock County, WI, Walworth County, WI

The radar

The Chicago radar (KLOT), 90 km from the middle of the area, began a volume at 20:23 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Tornado Watch 413Jul 13, 4:00 PM CDT

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 8.4 hours before the alert went out and 112 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: 3490 J/kg
Mixed-layer CIN: -51 J/kg
Mixed-layer LCL: 832 m above ground
0-6 km bulk shear: 55 kt
0-1 km storm-relative helicity: 86 m²/s²
0-3 km storm-relative helicity: 83 m²/s²
Significant tornado parameter: 1.7
Supercell composite: 6.3

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
Jul 13, 3:49 AM CDT	Mesoscale Discussion	SPC	Boone, Cook, DeKalb, DuPage, Grundy, Iroquois and 7 more	116 min
Jul 13, 4:14 AM CDT	Severe Thunderstorm Watch	SPC	Boone, Bureau, Carroll, Cook, DeKalb, DuPage and 18 more	6 hr
Jul 13, 7:19 AM CDT	Mesoscale Discussion	SPC	Ford, Grundy, Iroquois, Kankakee, Kendall, LaSalle and 2 more	86 min
Jul 13, 9:17 AM CDT	Severe Thunderstorm Watch	SPC	Champaign, Clark, Coles, Crawford, Cumberland, DeWitt and 16 more	4 hr
Jul 13, 11:01 AM CDT	Mesoscale Discussion	SPC	Edwards, Wabash, White	89 min
Jul 13, 4:01 PM CDT	Tornado Watch	SPC	Boone, Bureau, Carroll, Cass, Champaign, Christian and 52 more	7 hr
Jul 13, 4:33 PM CDT	Mesoscale Discussion	SPC	Adams, Bond, Brown, Calhoun, Christian, Clinton and 14 more	57 min
Jul 13, 6:20 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Bond, Brown, Calhoun, Clinton, Fayette and 11 more	4 hr
Jul 13, 6:59 PM CDT	Mesoscale Discussion	SPC	Boone, Brown, Bureau, Carroll, Cass, Champaign and 65 more	91 min
Jul 12, 7:51 PM CDT	Mesoscale Discussion	SPC	Dickinson, Emmet, Kossuth, Winnebago	114 min
Jul 12, 9:03 PM CDT	Mesoscale Discussion	SPC	Allamakee, Chickasaw, Howard, Winneshiek	117 min
Jul 12, 9:41 PM CDT	Mesoscale Discussion	SPC	Bremer, Butler, Cerro Gordo, Chickasaw, Floyd, Hancock and 4 more	94 min
Jul 12, 9:59 PM CDT	Severe Thunderstorm Watch	SPC	Allamakee, Bremer, Butler, Cerro Gordo, Chickasaw, Clayton and 7 more	6 hr
Jul 12, 11:55 PM CDT	Mesoscale Discussion	SPC	Allamakee, Bremer, Butler, Cerro Gordo, Chickasaw, Clayton and 7 more	95 min
Jul 13, 2:00 AM CDT	Mesoscale Discussion	SPC	Allamakee, Clayton, Fayette, Winneshiek	2 hr
Jul 13, 3:11 PM CDT	Severe Thunderstorm Watch	SPC	Allamakee	6 hr
Jul 13, 1:51 PM CDT	Mesoscale Discussion	SPC	Adams, Barron, Buffalo, Chippewa, Clark, Columbia and 21 more	84 min
Jul 13, 6:09 PM CDT	Mesoscale Discussion	SPC	Adams, Buffalo, Chippewa, Clark, Columbia, Crawford and 33 more	66 min

Nearby

Mesoscale Discussions in Illinois, 2015 Mesoscale Discussions in Wisconsin, 2015 Mesoscale Discussions in Iowa, 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.