Alert archive / Illinois / Mesoscale Discussions in 2015

Mesoscale Discussion 1940

November 11, 201518 counties in Illinois; 16 counties in Iowa; 7 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Nov 11, 2015, 2:24 PM CST for 18 counties in Illinois; 16 counties in Iowa; 7 counties in Missouri. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Nov 11, 2015, 2:24 PM CST (20:24 UTC)
Expired: Nov 11, 2015, 4:30 PM CST
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 80%

All 41 counties

Benton County, IA, Cedar County, IA, Clinton County, IA, Des Moines County, IA, Henry County, IA, Iowa County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Lee County, IA, Linn County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Van Buren County, IA, Washington County, IA, Adams County, IL, Brown County, IL, Cass County, IL, Fulton County, IL, Greene County, IL, Hancock County, IL, Henderson County, IL, Henry County, IL, Knox County, IL, Mason County, IL, McDonough County, IL, Mercer County, IL, Morgan County, IL, Pike County, IL, Rock Island County, IL, Schuyler County, IL, Scott County, IL, Warren County, IL, Audrain County, MO, Clark County, MO, Lewis County, MO, Marion County, MO, Monroe County, MO, Pike County, MO, Ralls County, MO

The radar

The Quad Cities radar (KDVN), 115 km from the middle of the area, began a volume at 20:27 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.

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 8.4 hours before the alert went out and 118 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: 1035 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 101 m²/s²
0-3 km storm-relative helicity: 238 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
Nov 11, 3:20 PM CST	Tornado Watch	SPC	Adams, Brown, Bureau, Carroll, Cass, Fulton and 23 more	6 hr
Nov 11, 5:46 PM CST	Mesoscale Discussion	SPC	Boone, Bureau, Carroll, DeKalb, DeWitt, Ford and 14 more	59 min
Nov 11, 10:17 AM CST	Mesoscale Discussion	SPC	Adair, Adams, Appanoose, Audubon, Benton, Black Hawk and 54 more	118 min
Nov 11, 11:25 AM CST	Tornado Watch	SPC	Adair, Adams, Appanoose, Audubon, Black Hawk, Boone and 41 more	6 hr
Nov 11, 12:38 PM CST	Mesoscale Discussion	SPC	Crawford, Harrison	67 min
Nov 11, 1:42 PM CST	Mesoscale Discussion	SPC	Adair, Adams, Appanoose, Audubon, Boone, Carroll and 24 more	93 min
Nov 11, 4:59 PM CST	Mesoscale Discussion	SPC	Allamakee, Clayton	91 min

Nearby

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