Alert archive / Wisconsin / Mesoscale Discussions in 2026

Mesoscale Discussion 481

April 17, 202613 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Apr 17, 2026, 5:06 PM CDT for 13 counties in Wisconsin. It was in force for 114 min.

The area

The outline as issued.

The facts

Issued: Apr 17, 2026, 5:06 PM CDT (22:06 UTC)
Expired: Apr 17, 2026, 7:00 PM CDT
In force: 114 min
Issued by: the Storm Prediction Center
Concerning: Tornado watch 129

Counties Adams County, WI, Clark County, WI, Forest County, WI, Jackson County, WI, Langlade County, WI, Lincoln County, WI, Marathon County, WI, Menominee County, WI, Oneida County, WI, Portage County, WI, Shawano County, WI, Waupaca County, WI, Wood County, WI

The radar

The Green Bay radar (KGRB), 121 km from the middle of the area, began a volume at 22:07 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

Minneapolis, MN (KMPX), launched 12:00Z, 10.1 hours before the alert went out and 320 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: 1 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2301 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 188 m²/s²
0-3 km storm-relative helicity: 229 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 17, 7:44 AM CDT	Mesoscale Discussion	SPC	Pierce, Saint Croix	91 min
Apr 17, 9:23 AM CDT	Severe Thunderstorm Watch	SPC	Adams, Ashland, Barron, Bayfield, Buffalo, Burnett and 29 more	11 hr
Apr 17, 11:48 AM CDT	Mesoscale Discussion	SPC	Adams, Buffalo, Columbia, Crawford, Dane, Dodge and 19 more	2 hr
Apr 17, 12:40 PM CDT	Tornado Watch	SPC	Adams, Brown, Buffalo, Calumet, Clark, Columbia and 43 more	9 hr
Apr 17, 2:05 PM CDT	Mesoscale Discussion	SPC	Lafayette	55 min
Apr 17, 2:49 PM CDT	Mesoscale Discussion	SPC	Buffalo, Crawford, La Crosse, Pepin, Trempealeau	116 min
Apr 17, 3:07 PM CDT	Mesoscale Discussion	SPC	Ashland, Barron, Bayfield, Burnett, Chippewa, Douglas and 9 more	53 min
Apr 17, 4:42 PM CDT	Mesoscale Discussion	SPC	Green, Kenosha, Milwaukee, Racine, Rock, Walworth and 1 more	2 hr

Nearby

Mesoscale Discussions in Wisconsin, 2026 Every mesoscale discussion in 2026

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.