Alert archive / Wisconsin / Severe Thunderstorm Watches in 2017

Severe Thunderstorm Watch 416

July 15, 201749 counties in Wisconsin

The Storm Prediction Center issued this severe thunderstorm watch at Jul 15, 2017, 5:53 PM CDT for 49 counties in Wisconsin. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Jul 15, 2017, 5:53 PM CDT (22:53 UTC)
Expired: Jul 16, 2017, 1:00 AM CDT
In force: 7 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1.5 in
Strongest gust expected: 60 kt

All 49 counties

Adams County, WI, Brown County, WI, Buffalo County, WI, Calumet County, WI, Clark County, WI, Columbia County, WI, Crawford County, WI, Dane County, WI, Dodge County, WI, Door County, WI, Fond du Lac County, WI, Grant County, WI, Green County, WI, Green Lake County, WI, Iowa County, WI, Jackson County, WI, Jefferson County, WI, Juneau County, WI, Kenosha County, WI, Kewaunee County, WI, La Crosse County, WI, Lafayette County, WI, Langlade County, WI, Manitowoc County, WI, Marathon County, WI, Marinette County, WI, Marquette County, WI, Menominee County, WI, Milwaukee County, WI, Monroe County, WI, Oconto County, WI, Outagamie County, WI, Ozaukee County, WI, Portage County, WI, Racine County, WI, Richland County, WI, Rock County, WI, Sauk County, WI, Shawano County, WI, Sheboygan County, WI, Trempealeau County, WI, Vernon County, WI, Walworth County, WI, Washington County, WI, Waukesha County, WI, Waupaca County, WI, Waushara County, WI, Winnebago County, WI, Wood County, WI

The radar

The La Crosse radar (KARX), 116 km from the middle of the area, began a volume at 22:55 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes: 10%
One or more EF2 to EF5 tornadoes: 5%
Ten or more severe wind reports: 30%
One or more gusts of 65 knots or more: 10%
Ten or more severe hail reports: 30%
One or more hailstones of 2 inches or more: 10%
Six or more combined severe hail and wind reports: 50%

Warnings issued inside it

11 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
Jul 15, 6:22 PM CDT	Severe Thunderstorm Warning	GRB	Door	23 min
Jul 15, 6:26 PM CDT	Severe Thunderstorm Warning	GRB	Marinette, Oconto	49 min
Jul 15, 7:04 PM CDT	Severe Thunderstorm Warning	GRB	Oconto, Shawano	41 min
Jul 15, 7:56 PM CDT	Severe Thunderstorm Warning	GRB	Brown, Outagamie	49 min
Jul 15, 8:34 PM CDT	Severe Thunderstorm Warning	GRB	Brown, Calumet, Manitowoc, Outagamie, Winnebago	56 min
Jul 15, 9:09 PM CDT	Severe Thunderstorm Warning	MKX	Fond du Lac, Sheboygan	66 min
Jul 15, 10:03 PM CDT	Severe Thunderstorm Warning	MKX	Fond du Lac, Ozaukee, Sheboygan, Washington	57 min
Jul 15, 10:12 PM CDT	Severe Thunderstorm Warning	MKX	Dodge, Fond du Lac	48 min
Jul 15, 11:20 PM CDT	Severe Thunderstorm Warning	MKX	Dodge, Jefferson, Milwaukee, Washington, Waukesha	40 min
Jul 15, 11:22 PM CDT	Severe Thunderstorm Warning	MKX	Columbia, Sauk	38 min
Jul 16, 12:54 AM CDT	Severe Thunderstorm Warning	MKX	Kenosha, Walworth	21 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 10.9 hours before the alert went out and 141 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: 1101 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 25 m²/s²
0-3 km storm-relative helicity: 58 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 15, 4:54 PM CDT	Mesoscale Discussion	SPC	Adams, Brown, Calumet, Fond du Lac, Green Lake, Langlade and 12 more	2 hr

Nearby

Severe Thunderstorm Watches in Wisconsin, 2017 Every severe thunderstorm watch 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.