Alert archive / Wisconsin / Mesoscale Discussions in 2017

Mesoscale Discussion 1293

July 12, 201712 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Jul 12, 2017, 3:56 AM CDT for 12 counties in Wisconsin. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Jul 12, 2017, 3:56 AM CDT (08:56 UTC)
Expired: Jul 12, 2017, 6:30 AM CDT
In force: 3 hr
Issued by: the Storm Prediction Center
Chance of a watch: 40%

Counties Chippewa County, WI, Clark County, WI, Eau Claire County, WI, Jackson County, WI, Langlade County, WI, Lincoln County, WI, Marathon County, WI, Portage County, WI, Rusk County, WI, Taylor County, WI, Waupaca County, WI, Wood County, WI

The radar

The La Crosse radar (KARX), 129 km from the middle of the area, began a volume at 08:56 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

Green Bay/Straub, WI (KGRB), launched 00:00Z, 8.9 hours before the alert went out and 204 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: 643 J/kg
Mixed-layer CIN: -29 J/kg
Mixed-layer LCL: 1366 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 80 m²/s²
0-3 km storm-relative helicity: 105 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.2

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
Jul 11, 9:49 PM CDT	Mesoscale Discussion	SPC	Crawford, Dane, Grant, Green, Iowa, Lafayette and 5 more	116 min
Jul 11, 10:00 PM CDT	Severe Thunderstorm Watch	SPC	Barron, Chippewa, Dunn, Eau Claire, Polk, Rusk and 1 more	6 hr
Jul 12, 1:49 AM CDT	Mesoscale Discussion	SPC	Adams, Barron, Buffalo, Burnett, Chippewa, Clark and 23 more	2 hr
Jul 12, 2:53 PM CDT	Mesoscale Discussion	SPC	Adams, Clark, Eau Claire, Forest, Jackson, Juneau and 16 more	97 min
Jul 12, 3:33 PM CDT	Severe Thunderstorm Watch	SPC	Brown, Calumet, Clark, Florence, Forest, Jackson and 18 more	7 hr
Jul 12, 6:19 PM CDT	Mesoscale Discussion	SPC	Adams, Crawford, Forest, Juneau, Langlade, Marathon and 11 more	86 min

Nearby

Mesoscale Discussions in Wisconsin, 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.