Alert archive / Iowa / Mesoscale Discussions in 2014

Mesoscale Discussion 327

April 12, 2014Carroll County, Jo Daviess County, Stephenson County, Illinois; 52 counties in Iowa; 9 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Apr 12, 2014, 6:20 PM CDT for Carroll County, Jo Daviess County, Stephenson County, Illinois; 52 counties in Iowa; 9 counties in Wisconsin. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued: Apr 12, 2014, 6:20 PM CDT (23:20 UTC)
Expired: Apr 12, 2014, 7:15 PM CDT
In force: 55 min
Issued by: the Storm Prediction Center

All 64 counties

Adair County, IA, Adams County, IA, Allamakee County, IA, Audubon County, IA, Benton County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Buchanan County, IA, Butler County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Cedar County, IA, Chickasaw County, IA, Clayton County, IA, Clinton County, IA, Crawford County, IA, Dallas County, IA, Delaware County, IA, Dubuque County, IA, Fayette County, IA, Floyd County, IA, Franklin County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hardin County, IA, Humboldt County, IA, Ida County, IA, Iowa County, IA, Jackson County, IA, Jasper County, IA, Johnson County, IA, Jones County, IA, Linn County, IA, Madison County, IA, Marion County, IA, Marshall County, IA, Montgomery County, IA, Polk County, IA, Pottawattamie County, IA, Poweshiek County, IA, Sac County, IA, Shelby County, IA, Story County, IA, Tama County, IA, Warren County, IA, Webster County, IA, Winneshiek County, IA, Wright County, IA, Carroll County, IL, Jo Daviess County, IL, Stephenson County, IL, Columbia County, WI, Crawford County, WI, Dane County, WI, Grant County, WI, Green County, WI, Iowa County, WI, Lafayette County, WI, Richland County, WI, Sauk County, WI

The radar

The Des Moines radar (KDMX), 89 km from the middle of the area, began a volume at 23:23 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.

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 11.3 hours before the alert went out and 225 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: 2231 m above ground
0-6 km bulk shear: 51 kt
0-1 km storm-relative helicity: 176 m²/s²
0-3 km storm-relative helicity: 360 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
Apr 12, 10:24 AM CDT	Mesoscale Discussion	SPC	Boone, Cook, DuPage, Kane, Lake, McHenry and 2 more	2 hr
Apr 12, 2:30 PM CDT	Mesoscale Discussion	SPC	Carroll, Jo Daviess, Stephenson	2 hr
Apr 12, 3:15 PM CDT	Severe Thunderstorm Watch	SPC	Carroll, Jo Daviess, Stephenson	7 hr
Apr 12, 4:46 PM CDT	Mesoscale Discussion	SPC	Adams, Cass, Fremont, Mills, Montgomery, Page and 4 more	59 min
Apr 12, 6:26 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Appanoose, Clarke, Davis, Decatur, Fremont and 10 more	8 hr

Nearby

Mesoscale Discussions in Iowa, 2014 Mesoscale Discussions in Wisconsin, 2014 Mesoscale Discussions in Illinois, 2014 Every mesoscale discussion in 2014

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.