Alert archive / Wisconsin / Mesoscale Discussions in 2009

Mesoscale Discussion 586

April 26, 2009Jo Daviess County, Stephenson County, Illinois; 4 counties in Iowa; 9 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Apr 26, 2009, 5:14 PM CDT for Jo Daviess County, Stephenson County, Illinois; 4 counties in Iowa; 9 counties in Wisconsin. It was in force for 61 min.

The area

The outline as issued.

The facts

Issued: Apr 26, 2009, 5:14 PM CDT (22:14 UTC)
Expired: Apr 26, 2009, 6:15 PM CDT
In force: 61 min
Issued by: the Storm Prediction Center

Counties Clayton County, IA, Delaware County, IA, Dubuque County, IA, Jackson County, IA, Jo Daviess County, IL, Stephenson County, IL, Crawford County, WI, Dane County, WI, Grant County, WI, Green County, WI, Iowa County, WI, Lafayette County, WI, Richland County, WI, Rock County, WI, Sauk County, WI

The radar

The Milwaukee radar (KMKX), 127 km from the middle of the area, began a volume at 22:14 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

Davenport, (KDVN), launched 12:00Z, 10.2 hours before the alert went out and 132 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: 586 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 402 m²/s²
0-3 km storm-relative helicity: 403 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

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 25, 9:23 PM CDT	Mesoscale Discussion	SPC	Hancock, Henderson, Knox, McDonough, Mercer, Warren	67 min
Apr 26, 2:00 PM CDT	Mesoscale Discussion	SPC	Boone, Carroll, DeKalb, Jo Daviess, Kane, Lee and 4 more	60 min
Apr 26, 5:02 PM CDT	Tornado Watch	SPC	Jo Daviess, Stephenson	6 hr
Apr 25, 7:17 PM CDT	Mesoscale Discussion	SPC	Appanoose, Davis, Wapello, Wayne	58 min
Apr 25, 10:09 PM CDT	Severe Thunderstorm Watch	SPC	Fremont, Page	6 hr
Apr 26, 9:18 AM CDT	Mesoscale Discussion	SPC	Audubon, Crawford, Harrison, Mills, Monona, Pottawattamie and 2 more	27 min
Apr 26, 9:34 AM CDT	Severe Thunderstorm Watch	SPC	Audubon, Buena Vista, Calhoun, Carroll, Cass, Cherokee and 29 more	6 hr
Apr 26, 12:30 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Audubon, Boone, Cass, Dallas and 13 more	60 min
Apr 26, 12:48 PM CDT	Tornado Watch	SPC	Adair, Adams, Audubon, Boone, Butler, Calhoun and 33 more	4 hr
Apr 26, 2:41 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Audubon, Boone, Buena Vista, Calhoun and 35 more	3 hr
Apr 26, 6:14 PM CDT	Mesoscale Discussion	SPC	Adams, Appanoose, Benton, Black Hawk, Bremer, Buchanan and 40 more	61 min

Nearby

Mesoscale Discussions in Wisconsin, 2009 Mesoscale Discussions in Iowa, 2009 Mesoscale Discussions in Illinois, 2009 Every mesoscale discussion in 2009

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.