Alert archive / Wisconsin / Mesoscale Discussions in 2023

Mesoscale Discussion 461

April 4, 202313 counties in Iowa; 10 counties in Minnesota; 15 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Apr 4, 2023, 5:34 PM CDT for 13 counties in Iowa; 10 counties in Minnesota; 15 counties in Wisconsin. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued: Apr 4, 2023, 5:34 PM CDT (22:34 UTC)
Expired: Apr 4, 2023, 7:00 PM CDT
In force: 86 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...severe thunderstorm watch likely
Chance of a watch: 80%

All 38 counties

Allamakee County, IA, Bremer County, IA, Butler County, IA, Cerro Gordo County, IA, Chickasaw County, IA, Clayton County, IA, Fayette County, IA, Floyd County, IA, Franklin County, IA, Howard County, IA, Mitchell County, IA, Winneshiek County, IA, Worth County, IA, Dodge County, MN, Fillmore County, MN, Freeborn County, MN, Goodhue County, MN, Houston County, MN, Mower County, MN, Olmsted County, MN, Steele County, MN, Wabasha County, MN, Winona County, MN, Adams County, WI, Columbia County, WI, Crawford County, WI, Dane County, WI, Grant County, WI, Green County, WI, Iowa County, WI, Juneau County, WI, La Crosse County, WI, Marquette County, WI, Monroe County, WI, Richland County, WI, Sauk County, WI, Trempealeau County, WI, Vernon County, WI

The radar

The La Crosse radar (KARX), 44 km from the middle of the area, began a volume at 22:33 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 117Apr 4, 6:35 PM CDT

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 10.6 hours before the alert went out and 198 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: 719 m above ground
0-6 km bulk shear: 69 kt
0-1 km storm-relative helicity: 246 m²/s²
0-3 km storm-relative helicity: 333 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 4, 8:00 AM CDT	Mesoscale Discussion	SPC	Cedar, Clinton, Delaware, Dubuque, Iowa, Jackson and 7 more	3 hr
Apr 4, 1:49 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Appanoose, Benton, Black Hawk, Boone and 43 more	116 min
Apr 4, 2:48 PM CDT	Tornado Watch	SPC	Adair, Adams, Appanoose, Audubon, Benton, Black Hawk and 50 more	7 hr
Apr 4, 2:54 PM CDT	Mesoscale Discussion	SPC	Allamakee, Bremer, Butler, Cerro Gordo, Chickasaw, Clayton and 10 more	3 hr
Apr 4, 6:18 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Appanoose, Benton, Boone, Calhoun and 44 more	87 min
Apr 4, 6:34 PM CDT	Severe Thunderstorm Watch	SPC	Allamakee, Black Hawk, Bremer, Buchanan, Butler, Cerro Gordo and 14 more	6 hr
Apr 4, 3:45 PM CDT	Mesoscale Discussion	SPC	Clay, Norman	4 hr
Apr 4, 12:53 PM CDT	Mesoscale Discussion	SPC	Kenosha	67 min

Nearby

Mesoscale Discussions in Wisconsin, 2023 Mesoscale Discussions in Iowa, 2023 Mesoscale Discussions in Minnesota, 2023 Every mesoscale discussion in 2023

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.