Alert archive / Iowa / Mesoscale Discussions in 2014

Mesoscale Discussion 328

April 12, 20147 counties in Illinois; 52 counties in Iowa; 22 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Apr 12, 2014, 9:08 PM CDT for 7 counties in Illinois; 52 counties in Iowa; 22 counties in Wisconsin. It was in force for 67 min.

The area

The outline as issued.

The facts

Issued: Apr 12, 2014, 9:08 PM CDT (02:08 UTC)
Expired: Apr 12, 2014, 10:15 PM CDT
In force: 67 min
Issued by: the Storm Prediction Center

All 81 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, Union County, IA, Warren County, IA, Webster County, IA, Wright County, IA, Boone County, IL, Carroll County, IL, Jo Daviess County, IL, McHenry County, IL, Ogle County, IL, Stephenson County, IL, Winnebago County, IL, Columbia County, WI, Crawford County, WI, Dane County, WI, Dodge County, WI, Fond du Lac County, WI, Grant County, WI, Green County, WI, Green Lake County, WI, Iowa County, WI, Jefferson County, WI, Kenosha County, WI, Lafayette County, WI, Milwaukee County, WI, Ozaukee County, WI, Racine County, WI, Richland County, WI, Rock County, WI, Sauk County, WI, Sheboygan County, WI, Walworth County, WI, Washington County, WI, Waukesha County, WI

The radar

The Des Moines radar (KDMX), 133 km from the middle of the area, began a volume at 02:09 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.

Severe Thunderstorm Watch 72Apr 12, 9:40 PM CDT

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 2.1 hours before the alert went out and 183 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: 661 J/kg
Mixed-layer CIN: -152 J/kg
Mixed-layer LCL: 1978 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 34 m²/s²
0-3 km storm-relative helicity: 80 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

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, 9:38 PM CDT	Severe Thunderstorm Watch	SPC	Boone, Carroll, Jo Daviess, Lake, McHenry, Ogle and 4 more	6 hr
Apr 12, 11:26 PM CDT	Mesoscale Discussion	SPC	Boone, Carroll, Jo Daviess, McHenry, Ogle, Rock Island and 3 more	64 min
Apr 13, 1:37 AM CDT	Mesoscale Discussion	SPC	Boone, Carroll, DeKalb, Jo Daviess, Lee, McHenry and 5 more	83 min
Apr 13, 7:41 AM CDT	Mesoscale Discussion	SPC	Adams, Brown, Calhoun, Greene, Hancock, Henderson and 5 more	2 hr
Apr 12, 9:12 PM CDT	Mesoscale Discussion	SPC	Decatur, Page, Ringgold, Taylor	63 min
Apr 13, 1:16 PM CDT	Mesoscale Discussion	SPC	Buena Vista, Carroll, Cherokee, Crawford, Harrison, Ida and 7 more	6 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.