Alert archive / Wisconsin / Mesoscale Discussions in 2004

Mesoscale Discussion 361

April 18, 20045 counties in Michigan; 17 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Apr 18, 2004, 2:49 AM EDT for 5 counties in Michigan; 17 counties in Wisconsin. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued: Apr 18, 2004, 2:49 AM EDT (06:49 UTC)
Expired: Apr 18, 2004, 3:45 AM EDT
In force: 56 min
Issued by: the Storm Prediction Center

All 22 counties

Benzie County, MI, Grand Traverse County, MI, Manistee County, MI, Mason County, MI, Wexford County, MI, Calumet County, WI, Columbia County, WI, Dane County, WI, Dodge County, WI, Fond du Lac County, WI, Green County, WI, Green Lake County, WI, Jefferson County, WI, Manitowoc County, WI, Marquette County, WI, Ozaukee County, WI, Rock County, WI, Sauk County, WI, Sheboygan County, WI, Washington County, WI, Waukesha County, WI, Winnebago County, WI

The radar

The Milwaukee radar (KMKX), 81 km from the middle of the area, began a volume at 06:50 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, 6.8 hours before the alert went out and 91 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: 2208 m above ground
0-6 km bulk shear: 74 kt
0-1 km storm-relative helicity: -11 m²/s²
0-3 km storm-relative helicity: 135 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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
Apr 18, 9:04 AM EDT	Mesoscale Discussion	SPC	Gogebic, Iron, Ontonagon	86 min
Apr 18, 12:26 PM EDT	Mesoscale Discussion	SPC	Alger, Dickinson, Marquette, Schoolcraft	3 hr
Apr 18, 7:35 PM EDT	Tornado Watch	SPC	Iron	5 hr
Apr 17, 11:05 PM EDT	Tornado Watch	SPC	Adams, Crawford, Grant, Green, Iowa, Juneau and 6 more	5 hr
Apr 18, 12:50 AM EDT	Mesoscale Discussion	SPC	Adams, Barron, Buffalo, Chippewa, Clark, Columbia and 35 more	85 min
Apr 18, 1:30 AM EDT	Severe Thunderstorm Watch	SPC	Barron, Buffalo, Chippewa, Dunn, Eau Claire, Pepin and 5 more	5 hr
Apr 18, 3:37 AM EDT	Mesoscale Discussion	SPC	Barron, Buffalo, Burnett, Chippewa, Clark, Douglas and 11 more	53 min
Apr 18, 5:43 AM EDT	Mesoscale Discussion	SPC	Ashland, Barron, Bayfield, Burnett, Douglas, Iron and 7 more	32 min
Apr 18, 1:39 PM EDT	Mesoscale Discussion	SPC	Bayfield, Burnett, Douglas	2 hr
Apr 18, 2:40 PM EDT	Tornado Watch	SPC	Ashland, Barron, Bayfield, Burnett, Douglas, Polk and 4 more	6 hr

Nearby

Mesoscale Discussions in Wisconsin, 2004 Mesoscale Discussions in Michigan, 2004 Every mesoscale discussion in 2004

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.