Alert archive / Wisconsin / Mesoscale Discussions in 2007

Mesoscale Discussion 1728

August 11, 20079 counties in Iowa; Fillmore County, Houston County, Minnesota; 14 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Aug 11, 2007, 9:43 PM CDT for 9 counties in Iowa; Fillmore County, Houston County, Minnesota; 14 counties in Wisconsin. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued: Aug 11, 2007, 9:43 PM CDT (02:43 UTC)
Expired: Aug 11, 2007, 11:15 PM CDT
In force: 92 min
Issued by: the Storm Prediction Center

All 25 counties

Allamakee County, IA, Bremer County, IA, Buchanan County, IA, Chickasaw County, IA, Clayton County, IA, Delaware County, IA, Fayette County, IA, Howard County, IA, Winneshiek County, IA, Fillmore County, MN, Houston County, MN, Adams County, WI, Crawford County, WI, Grant County, WI, Iowa County, WI, Juneau County, WI, La Crosse County, WI, Marquette County, WI, Monroe County, WI, Portage County, WI, Richland County, WI, Sauk County, WI, Vernon County, WI, Waushara County, WI, Wood County, WI

The radar

The La Crosse radar (KARX), 53 km from the middle of the area, began a volume at 02:45 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 587Aug 11, 10:00 PM CDT

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 2.7 hours before the alert went out and 221 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: 1137 J/kg
Mixed-layer CIN: -105 J/kg
Mixed-layer LCL: 1520 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 62 m²/s²
0-3 km storm-relative helicity: 120 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.9

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 11, 9:57 PM CDT	Severe Thunderstorm Watch	SPC	Allamakee, Howard, Mitchell, Winneshiek	5 hr
Aug 11, 11:46 PM CDT	Mesoscale Discussion	SPC	Allamakee, Howard, Mitchell, Winneshiek	119 min
Aug 12, 1:20 AM CDT	Mesoscale Discussion	SPC	Jackson	25 min
Aug 12, 2:52 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Audubon, Cass, Clarke, Decatur and 12 more	83 min
Aug 12, 3:56 PM CDT	Severe Thunderstorm Watch	SPC	Adair, Adams, Appanoose, Audubon, Cass, Clarke and 16 more	7 hr
Aug 12, 5:49 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Audubon, Cass, Dallas, Guthrie and 9 more	86 min
Aug 11, 8:45 PM CDT	Mesoscale Discussion	SPC	Blue Earth, Chisago, Dakota, Dodge, Fillmore, Freeborn and 14 more	90 min

Nearby

Mesoscale Discussions in Wisconsin, 2007 Mesoscale Discussions in Iowa, 2007 Mesoscale Discussions in Minnesota, 2007 Every mesoscale discussion in 2007

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.