Alert archive / Iowa / Mesoscale Discussions in 2004

Mesoscale Discussion 1811

July 31, 200425 counties in Iowa; 20 counties in Minnesota; 10 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Jul 31, 2004, 11:41 PM CDT for 25 counties in Iowa; 20 counties in Minnesota; 10 counties in Wisconsin. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued
Jul 31, 2004, 11:41 PM CDT (04:41 UTC)
Expired
Aug 1, 2004, 12:45 AM CDT
In force
64 min
Issued by
the Storm Prediction Center
All 55 counties

Buena Vista County, IA, Calhoun County, IA, Cerro Gordo County, IA, Cherokee County, IA, Chickasaw County, IA, Clay County, IA, Dickinson County, IA, Emmet County, IA, Floyd County, IA, Franklin County, IA, Hancock County, IA, Howard County, IA, Humboldt County, IA, Kossuth County, IA, Mitchell County, IA, O'Brien County, IA, Palo Alto County, IA, Plymouth County, IA, Pocahontas County, IA, Sac County, IA, Webster County, IA, Winnebago County, IA, Winneshiek County, IA, Worth County, IA, Wright County, IA, Blue Earth County, MN, Dakota County, MN, Dodge County, MN, Faribault County, MN, Fillmore County, MN, Freeborn County, MN, Goodhue County, MN, Houston County, MN, Le Sueur County, MN, Martin County, MN, Mower County, MN, Olmsted County, MN, Ramsey County, MN, Rice County, MN, Scott County, MN, Steele County, MN, Wabasha County, MN, Waseca County, MN, Washington County, MN, Winona County, MN, Buffalo County, WI, Eau Claire County, WI, Jackson County, WI, La Crosse County, WI, Monroe County, WI, Pepin County, WI, Pierce County, WI, Saint Croix County, WI, Trempealeau County, WI, Wood County, WI

The radar

The Minneapolis radar (KMPX), 161 km from the middle of the area, began a volume at 04:44 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, 4.7 hours before the alert went out and 161 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-pSkew-T log-p diagram, Minneapolis, MN at 00:00Z on 2004-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 465 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 00:00Z on 2004-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 191 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
465 J/kg
Mixed-layer CIN
-74 J/kg
Mixed-layer LCL
1194 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
191 m²/s²
0-3 km storm-relative helicity
395 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.6

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.

IssuedProductOfficeCountiesLasted
Jul 31, 8:19 PM CDTMesoscale DiscussionSPCDickinson, Emmet, Lyon, Osceola, Winnebago56 min
Jul 31, 9:45 PM CDTSevere Thunderstorm WatchSPCBuena Vista, Cherokee, Clay, Dickinson, Emmet, Hancock and 10 more5 hr
Aug 1, 1:59 AM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Boone, Carroll, Cass and 24 more91 min
Aug 1, 5:56 AM CDTMesoscale DiscussionSPCAdair, Adams, Appanoose, Audubon, Boone, Bremer and 59 more94 min
Aug 1, 12:11 PM CDTMesoscale DiscussionSPCBuena Vista, Calhoun, Carroll, Cherokee, Crawford, Greene and 3 more64 min
Aug 1, 1:48 PM CDTMesoscale DiscussionSPCBuena Vista, Calhoun, Carroll, Cherokee, Clay, Crawford and 17 more117 min
Aug 1, 2:17 PM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Cass, Clarke, Dallas and 15 more58 min
Aug 1, 3:15 PM CDTTornado WatchSPCBig Stone, Brown, Chippewa, Cottonwood, Douglas, Grant and 21 more7 hr
Aug 1, 3:41 PM CDTMesoscale DiscussionSPCKanabec, Mille Lacs, Morrison, Pine2 hr
Aug 1, 4:00 PM CDTSevere Thunderstorm WatchSPCAitkin, Benton, Chisago, Crow Wing, Isanti, Kanabec and 3 more5 hr
Aug 1, 6:25 PM CDTMesoscale DiscussionSPCLanglade, Lincoln, Menominee, Oneida, Price, Shawano65 min

Nearby

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