Alert archive / Minnesota / Mesoscale Discussions in 2012

Mesoscale Discussion 1559

July 23, 20124 states

The Storm Prediction Center issued this mesoscale discussion at Jul 23, 2012, 11:13 PM CDT for 4 states. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued: Jul 23, 2012, 11:13 PM CDT (04:13 UTC)
Expired: Jul 24, 2012, 12:45 AM CDT
In force: 92 min
Issued by: the Storm Prediction Center
Chance of a watch: 40%

All 53 counties

Allamakee County, IA, Chickasaw County, IA, Clayton County, IA, Howard County, IA, Mitchell County, IA, Winneshiek County, IA, Worth County, IA, Stephenson County, IL, Blue Earth County, MN, Brown County, MN, Cottonwood County, MN, Dakota County, MN, Dodge County, MN, Faribault County, MN, Fillmore County, MN, Freeborn County, MN, Goodhue County, MN, Houston County, MN, Jackson County, MN, Le Sueur County, MN, Lincoln County, MN, Lyon County, MN, Martin County, MN, McLeod County, MN, Mower County, MN, Murray County, MN, Nicollet County, MN, Nobles County, MN, Olmsted County, MN, Pipestone County, MN, Redwood County, MN, Renville County, MN, Rice County, MN, Scott County, MN, Sibley County, MN, Steele County, MN, Wabasha County, MN, Waseca County, MN, Watonwan County, MN, Winona County, MN, Yellow Medicine County, MN, Buffalo County, WI, Crawford County, WI, Dane County, WI, Grant County, WI, Green County, WI, Iowa County, WI, La Crosse County, WI, Lafayette County, WI, Monroe County, WI, Richland County, WI, Sauk County, WI, Vernon County, WI

The radar

The Minneapolis radar (KMPX), 100 km from the middle of the area, began a volume at 04:13 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

Minneapolis, MN (KMPX), launched 00:00Z, 4.2 hours before the alert went out and 100 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: 583 J/kg
Mixed-layer CIN: -131 J/kg
Mixed-layer LCL: 1695 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: -16 m²/s²
0-3 km storm-relative helicity: 44 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.6

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
Jul 24, 3:32 AM CDT	Mesoscale Discussion	SPC	Boone, Bureau, Carroll, DeKalb, DuPage, Grundy and 10 more	58 min
Jul 24, 4:47 AM CDT	Severe Thunderstorm Watch	SPC	Boone, Cook, DeKalb, DuPage, Kane, Kankakee and 7 more	4 hr
Jul 24, 6:35 AM CDT	Mesoscale Discussion	SPC	Cook, DeKalb, DuPage, Grundy, Kane, Kankakee and 4 more	55 min
Jul 24, 3:25 PM CDT	Mesoscale Discussion	SPC	Clay, Clinton, Crawford, Edwards, Effingham, Fayette and 20 more	95 min

Nearby

Mesoscale Discussions in Minnesota, 2012 Mesoscale Discussions in Wisconsin, 2012 Mesoscale Discussions in Iowa, 2012 Every mesoscale discussion in 2012

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.