Alert archive / Iowa / Mesoscale Discussions in 2004

Mesoscale Discussion 769

May 19, 200421 counties in Iowa; 14 counties in Minnesota; 7 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at May 19, 2004, 7:12 PM CDT for 21 counties in Iowa; 14 counties in Minnesota; 7 counties in Wisconsin. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: May 19, 2004, 7:12 PM CDT (00:12 UTC)
Expired: May 19, 2004, 9:15 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 42 counties

Audubon County, IA, Calhoun County, IA, Carroll County, IA, Emmet County, IA, Floyd County, IA, Franklin County, IA, Greene County, IA, Guthrie County, IA, Hamilton County, IA, Hancock County, IA, Howard County, IA, Humboldt County, IA, Jasper County, IA, Kossuth County, IA, Marshall County, IA, Mitchell County, IA, Palo Alto County, IA, Pocahontas County, IA, Webster County, IA, Winnebago County, IA, Wright County, IA, Blue Earth County, MN, Dakota County, MN, Faribault County, MN, Fillmore County, MN, Goodhue County, MN, Martin County, MN, Mower County, MN, Olmsted County, MN, Rice County, MN, Scott County, MN, Wabasha County, MN, Waseca County, MN, Watonwan County, MN, Winona County, MN, Buffalo County, WI, Dunn County, WI, Eau Claire County, WI, Jackson County, WI, Pepin County, WI, Pierce County, WI, Trempealeau County, WI

The radar

The La Crosse radar (KARX), 128 km from the middle of the area, began a volume at 00:12 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, 0.2 hours before the alert went out and 138 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: 6 J/kg
Mixed-layer CIN: -199 J/kg
Mixed-layer LCL: 893 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 181 m²/s²
0-3 km storm-relative helicity: 296 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.1

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
May 20, 11:31 AM CDT	Mesoscale Discussion	SPC	Adair, Benton, Black Hawk, Boone, Buchanan, Cedar and 37 more	2 hr
May 20, 3:35 PM CDT	Severe Thunderstorm Watch	SPC	Benton, Black Hawk, Buchanan, Cedar, Clinton, Delaware and 15 more	6 hr
May 20, 4:54 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Appanoose, Audubon, Boone, Cass and 33 more	96 min
May 20, 5:00 PM CDT	Tornado Watch	SPC	Adair, Adams, Appanoose, Audubon, Cass, Clarke and 23 more	5 hr
May 19, 7:31 PM CDT	Mesoscale Discussion	SPC	Becker, Beltrami, Benton, Big Stone, Brown, Carver and 46 more	119 min
May 19, 8:00 PM CDT	Severe Thunderstorm Watch	SPC	Becker, Beltrami, Big Stone, Cass, Chippewa, Clay and 28 more	5 hr

Nearby

Mesoscale Discussions in Iowa, 2004 Mesoscale Discussions in Minnesota, 2004 Mesoscale Discussions in Wisconsin, 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.