Alert archive / Wisconsin / Mesoscale Discussions in 2017

Mesoscale Discussion 472

April 9, 20177 counties in Minnesota; 31 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Apr 9, 2017, 11:32 PM CDT for 7 counties in Minnesota; 31 counties in Wisconsin. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued: Apr 9, 2017, 11:32 PM CDT (04:32 UTC)
Expired: Apr 10, 2017, 12:30 AM CDT
In force: 58 min
Issued by: the Storm Prediction Center

All 38 counties

Dodge County, MN, Fillmore County, MN, Houston County, MN, Mower County, MN, Olmsted County, MN, Wabasha County, MN, Winona County, MN, Adams County, WI, Buffalo County, WI, Chippewa County, WI, Clark County, WI, Dunn County, WI, Eau Claire County, WI, Forest County, WI, Jackson County, WI, Juneau County, WI, La Crosse County, WI, Langlade County, WI, Lincoln County, WI, Marathon County, WI, Marinette County, WI, Marquette County, WI, Menominee County, WI, Monroe County, WI, Oconto County, WI, Oneida County, WI, Outagamie County, WI, Pepin County, WI, Portage County, WI, Price County, WI, Rusk County, WI, Shawano County, WI, Taylor County, WI, Trempealeau County, WI, Vernon County, WI, Waupaca County, WI, Waushara County, WI, Wood County, WI

The radar

The La Crosse radar (KARX), 84 km from the middle of the area, began a volume at 04:34 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 137Apr 10, 12:00 AM CDT

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 00:00Z, 4.5 hours before the alert went out and 192 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: -294 J/kg
Mixed-layer LCL: 1327 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: 210 m²/s²
0-3 km storm-relative helicity: 270 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

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 9, 8:06 PM CDT	Mesoscale Discussion	SPC	Dakota, Dodge, Faribault, Fillmore, Freeborn, Goodhue and 11 more	54 min
Apr 9, 9:01 PM CDT	Severe Thunderstorm Watch	SPC	Fillmore, Houston, Mower, Olmsted, Wabasha, Winona	4 hr
Apr 10, 12:01 AM CDT	Severe Thunderstorm Watch	SPC	Florence, Forest, Langlade, Lincoln, Marathon, Oneida and 3 more	3 hr
Apr 10, 2:16 AM CDT	Mesoscale Discussion	SPC	Adams, Brown, Calumet, Columbia, Crawford, Dane and 26 more	119 min
Apr 10, 11:57 AM CDT	Mesoscale Discussion	SPC	Kenosha, Milwaukee, Racine, Walworth	3 hr
Apr 10, 1:48 PM CDT	Severe Thunderstorm Watch	SPC	Dane, Dodge, Green, Jefferson, Kenosha, Lafayette and 7 more	8 hr
Apr 10, 3:25 PM CDT	Mesoscale Discussion	SPC	Jefferson, Kenosha, Milwaukee, Racine, Rock, Walworth and 1 more	2 hr
Apr 10, 6:22 PM CDT	Mesoscale Discussion	SPC	Kenosha, Racine	53 min

Nearby

Mesoscale Discussions in Wisconsin, 2017 Mesoscale Discussions in Minnesota, 2017 Every mesoscale discussion in 2017

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.