Alert archive / Illinois / Mesoscale Discussions in 2017

Mesoscale Discussion 479

April 10, 20174 states

The Storm Prediction Center issued this mesoscale discussion at Apr 10, 2017, 6:22 PM CDT for 4 states. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued: Apr 10, 2017, 6:22 PM CDT (23:22 UTC)
Expired: Apr 10, 2017, 7:15 PM CDT
In force: 53 min
Issued by: the Storm Prediction Center

All 67 counties

Champaign County, IL, Christian County, IL, Coles County, IL, Cook County, IL, DeWitt County, IL, Douglas County, IL, DuPage County, IL, Fayette 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, Logan County, IL, Macon County, IL, McLean County, IL, Montgomery County, IL, Moultrie County, IL, Piatt County, IL, Shelby County, IL, Vermilion County, IL, Will County, IL, Benton County, IN, Elkhart County, IN, Fulton County, IN, Jasper County, IN, Kosciusko County, IN, LaGrange County, IN, Lake County, IN, LaPorte County, IN, Marshall County, IN, Newton County, IN, Porter County, IN, Pulaski County, IN, Saint Joseph County, IN, Starke County, IN, Warren County, IN, White County, IN, Allegan County, MI, Barry County, MI, Berrien County, MI, Branch County, MI, Calhoun County, MI, Cass County, MI, Clinton County, MI, Eaton County, MI, Gratiot County, MI, Ingham County, MI, Ionia County, MI, Isabella County, MI, Kalamazoo County, MI, Kent County, MI, Lake County, MI, Mecosta County, MI, Montcalm County, MI, Muskegon County, MI, Newaygo County, MI, Oceana County, MI, Osceola County, MI, Ottawa County, MI, Saint Joseph County, MI, Van Buren County, MI, Kenosha County, WI, Racine County, WI

The radar

The Chicago radar (KLOT), 77 km from the middle of the area, began a volume at 23:24 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, 11.4 hours before the alert went out and 161 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1373 m above ground
0-6 km bulk shear: 61 kt
0-1 km storm-relative helicity: -63 m²/s²
0-3 km storm-relative helicity: 3 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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
Apr 10, 1:53 AM CDT	Mesoscale Discussion	SPC	Bureau, Carroll, Hancock, Henderson, Henry, Jo Daviess and 9 more	2 hr
Apr 10, 11:57 AM CDT	Mesoscale Discussion	SPC	Boone, Bureau, Cook, DeKalb, DuPage, Ford and 23 more	3 hr
Apr 10, 1:48 PM CDT	Severe Thunderstorm Watch	SPC	Boone, Bureau, Carroll, Cass, Champaign, Christian and 48 more	8 hr
Apr 10, 3:25 PM CDT	Mesoscale Discussion	SPC	Bond, Boone, Bureau, Cass, Champaign, Christian and 54 more	2 hr
Apr 10, 12:01 AM CDT	Severe Thunderstorm Watch	SPC	Dickinson, Iron, Marquette	3 hr
Apr 10, 2:16 AM CDT	Mesoscale Discussion	SPC	Alger, Delta, Dickinson, Marquette, Menominee, Schoolcraft	119 min
Apr 9, 8:06 PM CDT	Mesoscale Discussion	SPC	Barron, Buffalo, Chippewa, Clark, Dunn, Eau Claire and 8 more	54 min
Apr 9, 9:01 PM CDT	Severe Thunderstorm Watch	SPC	Buffalo, Chippewa, Clark, Dunn, Eau Claire, Jackson and 3 more	4 hr
Apr 9, 11:32 PM CDT	Mesoscale Discussion	SPC	Adams, Buffalo, Chippewa, Clark, Dunn, Eau Claire and 25 more	58 min

Nearby

Mesoscale Discussions in Illinois, 2017 Mesoscale Discussions in Michigan, 2017 Mesoscale Discussions in Indiana, 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.