Alert archive / Michigan / Mesoscale Discussions in 2011

Mesoscale Discussion 1647

July 18, 201119 counties in Michigan; 5 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Jul 18, 2011, 12:06 AM EDT for 19 counties in Michigan; 5 counties in Wisconsin. It was in force for 54 min.

The area

The outline as issued.

The facts

Issued: Jul 18, 2011, 12:06 AM EDT (04:06 UTC)
Expired: Jul 18, 2011, 1:00 AM EDT
In force: 54 min
Issued by: the Storm Prediction Center

All 24 counties

Antrim County, MI, Benzie County, MI, Charlevoix County, MI, Cheboygan County, MI, Crawford County, MI, Emmet County, MI, Grand Traverse County, MI, Kalkaska County, MI, Lake County, MI, Leelanau County, MI, Manistee County, MI, Mason County, MI, Missaukee County, MI, Montmorency County, MI, Oceana County, MI, Osceola County, MI, Otsego County, MI, Roscommon County, MI, Wexford County, MI, Calumet County, WI, Fond du Lac County, WI, Kewaunee County, WI, Manitowoc County, WI, Sheboygan County, WI

The radar

The NCL Michigan radar (KAPX), 128 km from the middle of the area, began a volume at 04:10 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, 4.1 hours before the alert went out and 149 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: 3989 J/kg
Mixed-layer CIN: -33 J/kg
Mixed-layer LCL: 1231 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 70 m²/s²
0-3 km storm-relative helicity: 142 m²/s²
Significant tornado parameter: 2.2
Supercell composite: 17.3

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
Jul 17, 10:24 PM EDT	Mesoscale Discussion	SPC	Menominee	66 min
Jul 18, 10:54 AM EDT	Mesoscale Discussion	SPC	Lake, Manistee, Mason, Mecosta, Muskegon, Newaygo and 1 more	96 min
Jul 18, 1:29 PM EDT	Mesoscale Discussion	SPC	Bay, Clare, Clinton, Eaton, Genesee, Gladwin and 18 more	91 min
Jul 17, 8:22 PM EDT	Severe Thunderstorm Watch	SPC	Brown, Calumet, Door, Florence, Forest, Kewaunee and 17 more	4 hr
Jul 18, 7:30 AM EDT	Mesoscale Discussion	SPC	Adams, Clark, Columbia, Crawford, Dane, Dodge and 25 more	2 hr
Jul 18, 9:05 AM EDT	Severe Thunderstorm Watch	SPC	Adams, Brown, Buffalo, Calumet, Clark, Columbia and 32 more	4 hr
Jul 18, 3:06 PM EDT	Mesoscale Discussion	SPC	Barron, Brown, Chippewa, Clark, Dunn, Eau Claire and 17 more	84 min
Jul 18, 3:26 PM EDT	Severe Thunderstorm Watch	SPC	Adams, Brown, Calumet, Chippewa, Clark, Door and 28 more	7 hr
Jul 18, 6:42 PM EDT	Mesoscale Discussion	SPC	Adams, Brown, Calumet, Chippewa, Clark, Eau Claire and 21 more	63 min
Jul 18, 7:18 PM EDT	Severe Thunderstorm Watch	SPC	Columbia, Dane, Dodge, Fond du Lac, Green, Green Lake and 14 more	3 hr

Nearby

Mesoscale Discussions in Michigan, 2011 Mesoscale Discussions in Wisconsin, 2011 Every mesoscale discussion in 2011

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.