Alert archive / Wisconsin / Mesoscale Discussions in 2013

Mesoscale Discussion 1749

August 21, 201313 counties in Michigan; 16 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Aug 21, 2013, 9:14 PM EDT for 13 counties in Michigan; 16 counties in Wisconsin. It was in force for 61 min.

The area

The outline as issued.

The facts

Issued: Aug 21, 2013, 9:14 PM EDT (01:14 UTC)
Expired: Aug 21, 2013, 10:15 PM EDT
In force: 61 min
Issued by: the Storm Prediction Center

All 29 counties

Antrim County, MI, Benzie County, MI, Charlevoix County, MI, Crawford County, MI, Grand Traverse County, MI, Kalkaska County, MI, Lake County, MI, Leelanau County, MI, Manistee County, MI, Mason County, MI, Missaukee County, MI, Osceola County, MI, Wexford County, MI, Brown County, WI, Calumet County, WI, Door County, WI, Fond du Lac County, WI, Green Lake County, WI, Kewaunee County, WI, Manitowoc County, WI, Menominee County, WI, Oconto County, WI, Outagamie County, WI, Ozaukee County, WI, Shawano County, WI, Sheboygan County, WI, Waupaca County, WI, Waushara County, WI, Winnebago County, WI

The radar

The Green Bay radar (KGRB), 76 km from the middle of the area, began a volume at 01:15 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, 1.2 hours before the alert went out and 76 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: 2954 J/kg
Mixed-layer CIN: -18 J/kg
Mixed-layer LCL: 1211 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 85 m²/s²
0-3 km storm-relative helicity: 141 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 5.6

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 22, 1:10 PM EDT	Mesoscale Discussion	SPC	Allegan, Barry, Branch, Calhoun, Cass, Clinton and 16 more	3 hr

Nearby

Mesoscale Discussions in Wisconsin, 2013 Mesoscale Discussions in Michigan, 2013 Every mesoscale discussion in 2013

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.