Alert archive / Michigan / Mesoscale Discussions in 2011

Mesoscale Discussion 2026

August 20, 20114 states

The Storm Prediction Center issued this mesoscale discussion at Aug 20, 2011, 11:04 AM CDT for 4 states. It was in force for 116 min.

The area

The outline as issued.

The facts

Issued: Aug 20, 2011, 11:04 AM CDT (16:04 UTC)
Expired: Aug 20, 2011, 1:00 PM CDT
In force: 116 min
Issued by: the Storm Prediction Center

All 65 counties

Kankakee County, IL, Allen County, IN, Cass County, IN, DeKalb County, IN, Elkhart County, IN, Fulton County, IN, Huntington County, IN, Jasper County, IN, Kosciusko County, IN, LaGrange County, IN, Lake County, IN, LaPorte County, IN, Marshall County, IN, Miami County, IN, Newton County, IN, Noble County, IN, Porter County, IN, Pulaski County, IN, Saint Joseph County, IN, Starke County, IN, Steuben County, IN, Wabash County, IN, White County, IN, Whitley County, IN, Barry County, MI, Berrien County, MI, Branch County, MI, Calhoun County, MI, Cass County, MI, Clinton County, MI, Eaton County, MI, Genesee County, MI, Hillsdale County, MI, Ingham County, MI, Ionia County, MI, Jackson County, MI, Kalamazoo County, MI, Kent County, MI, Lapeer County, MI, Lenawee County, MI, Livingston County, MI, Macomb County, MI, Monroe County, MI, Oakland County, MI, Saint Clair County, MI, Saint Joseph County, MI, Sanilac County, MI, Shiawassee County, MI, Tuscola County, MI, Washtenaw County, MI, Wayne County, MI, Defiance County, OH, Erie County, OH, Fulton County, OH, Hancock County, OH, Henry County, OH, Lucas County, OH, Ottawa County, OH, Paulding County, OH, Putnam County, OH, Sandusky County, OH, Seneca County, OH, Van Wert County, OH, Williams County, OH, Wood County, OH

The radar

The Northern Indiana radar (KIWX), 85 km from the middle of the area, began a volume at 16:05 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Severe Thunderstorm Watch 792Aug 20, 12:40 PM CDT

The nearest sounding before it

Detroit, MI (KDTX), launched 12:00Z, 4.1 hours before the alert went out and 160 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: 1765 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 56 m²/s²
0-3 km storm-relative helicity: 68 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
Aug 20, 12:41 PM CDT	Severe Thunderstorm Watch	SPC	Allegan, Barry, Calhoun, Clinton, Eaton, Genesee and 20 more	4 hr
Aug 20, 3:37 PM CDT	Mesoscale Discussion	SPC	Macomb, Saint Clair, Wayne	83 min

Nearby

Mesoscale Discussions in Michigan, 2011 Mesoscale Discussions in Indiana, 2011 Mesoscale Discussions in Ohio, 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.