Alert archive / Michigan / Mesoscale Discussions in 2004

Mesoscale Discussion 2132

August 27, 200429 counties in Michigan

The Storm Prediction Center issued this mesoscale discussion at Aug 27, 2004, 1:39 PM EDT for 29 counties in Michigan. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Aug 27, 2004, 1:39 PM EDT (17:39 UTC)
Expired: Aug 27, 2004, 3:45 PM EDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 29 counties

Barry County, MI, Bay County, MI, Calhoun County, MI, Clinton County, MI, Eaton County, MI, Genesee County, MI, Gratiot County, MI, Huron County, MI, Ingham County, MI, Ionia County, MI, Isabella County, MI, Jackson County, MI, Kalamazoo County, MI, Kent County, MI, Lapeer County, MI, Livingston County, MI, Macomb County, MI, Mecosta County, MI, Midland County, MI, Montcalm County, MI, Newaygo County, MI, Oakland County, MI, Saginaw County, MI, Saint Joseph County, MI, Sanilac County, MI, Shiawassee County, MI, Tuscola County, MI, Washtenaw County, MI, Wayne County, MI

The radar

The Grand Rapids radar (KGRR), 75 km from the middle of the area, began a volume at 17:43 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

Detroit, MI (KDTX), launched 12:00Z, 5.7 hours before the alert went out and 99 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: 1956 J/kg
Mixed-layer CIN: -50 J/kg
Mixed-layer LCL: 606 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 107 m²/s²
0-3 km storm-relative helicity: 136 m²/s²
Significant tornado parameter: 1.0
Supercell composite: 7.0

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
Aug 27, 2:25 AM EDT	Severe Thunderstorm Watch	SPC	Allegan, Arenac, Barry, Bay, Berrien, Cass and 21 more	6 hr
Aug 27, 2:39 AM EDT	Mesoscale Discussion	SPC	Antrim, Arenac, Benzie, Cheboygan, Clare, Crawford and 15 more	66 min
Aug 27, 5:36 AM EDT	Mesoscale Discussion	SPC	Allegan, Arenac, Barry, Bay, Berrien, Branch and 36 more	84 min
Aug 27, 7:33 AM EDT	Mesoscale Discussion	SPC	Arenac, Bay, Branch, Calhoun, Clinton, Eaton and 17 more	27 min

Nearby

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.