Alert archive / South Dakota / Mesoscale Discussions in 2004

Mesoscale Discussion 373

April 18, 20044 counties in Minnesota; 14 counties in Nebraska; 22 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Apr 18, 2004, 5:23 PM CDT for 4 counties in Minnesota; 14 counties in Nebraska; 22 counties in South Dakota. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Apr 18, 2004, 5:23 PM CDT (22:23 UTC)
Expired: Apr 18, 2004, 7:30 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 40 counties

Lincoln County, MN, Lyon County, MN, Pipestone County, MN, Rock County, MN, Antelope County, NE, Boyd County, NE, Cedar County, NE, Dixon County, NE, Garfield County, NE, Holt County, NE, Knox County, NE, Loup County, NE, Madison County, NE, Pierce County, NE, Rock County, NE, Stanton County, NE, Wayne County, NE, Wheeler County, NE, Aurora County, SD, Beadle County, SD, Bon Homme County, SD, Brookings County, SD, Charles Mix County, SD, Clay County, SD, Davison County, SD, Douglas County, SD, Hanson County, SD, Hutchinson County, SD, Jerauld County, SD, Kingsbury County, SD, Lake County, SD, Lincoln County, SD, McCook County, SD, Miner County, SD, Minnehaha County, SD, Moody County, SD, Sanborn County, SD, Turner County, SD, Union County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 108 km from the middle of the area, began a volume at 22:23 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

Omaha, NE (KOAX), launched 12:00Z, 10.4 hours before the alert went out and 204 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: 256 J/kg
Mixed-layer CIN: -464 J/kg
Mixed-layer LCL: 995 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 365 m²/s²
0-3 km storm-relative helicity: 406 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 17, 7:45 PM CDT	Severe Thunderstorm Watch	SPC	Blue Earth, Dodge, Faribault, Fillmore, Freeborn, Houston and 7 more	5 hr
Apr 17, 9:31 PM CDT	Mesoscale Discussion	SPC	Blue Earth, Dodge, Faribault, Fillmore, Freeborn, Houston and 7 more	119 min
Apr 17, 10:05 PM CDT	Tornado Watch	SPC	Blue Earth, Dodge, Faribault, Fillmore, Freeborn, Houston and 7 more	5 hr
Apr 17, 11:10 PM CDT	Mesoscale Discussion	SPC	Big Stone, Chippewa, Cottonwood, Grant, Jackson, Kandiyohi and 14 more	95 min
Apr 17, 11:35 PM CDT	Severe Thunderstorm Watch	SPC	Big Stone, Brown, Chippewa, Cottonwood, Jackson, Kandiyohi and 16 more	5 hr
Apr 17, 11:50 PM CDT	Mesoscale Discussion	SPC	Blue Earth, Dodge, Faribault, Fillmore, Freeborn, Houston and 7 more	85 min
Apr 18, 12:30 AM CDT	Severe Thunderstorm Watch	SPC	Anoka, Carver, Chisago, Dakota, Goodhue, Hennepin and 11 more	5 hr
Apr 18, 2:37 AM CDT	Mesoscale Discussion	SPC	Aitkin, Anoka, Benton, Big Stone, Brown, Carlton and 40 more	53 min
Apr 18, 4:43 AM CDT	Mesoscale Discussion	SPC	Aitkin, Benton, Carlton, Cass, Chisago, Crow Wing and 15 more	32 min
Apr 18, 8:04 AM CDT	Mesoscale Discussion	SPC	Aitkin, Benton, Carlton, Cass, Crow Wing, Douglas and 6 more	86 min
Apr 18, 12:39 PM CDT	Mesoscale Discussion	SPC	Aitkin, Anoka, Benton, Big Stone, Carlton, Carver and 32 more	2 hr
Apr 18, 1:40 PM CDT	Tornado Watch	SPC	Aitkin, Anoka, Benton, Carlton, Carver, Chippewa and 32 more	6 hr
Apr 18, 2:20 PM CDT	Severe Thunderstorm Watch	SPC	Lincoln, Lyon, Pipestone, Rock	6 hr
Apr 18, 3:33 PM CDT	Mesoscale Discussion	SPC	Aitkin, Anoka, Benton, Carlton, Chisago, Crow Wing and 12 more	117 min
Apr 18, 4:15 PM CDT	Mesoscale Discussion	SPC	Blue Earth, Brown, Cottonwood, Dodge, Faribault, Fillmore and 15 more	60 min
Apr 18, 4:40 PM CDT	Tornado Watch	SPC	Blue Earth, Cottonwood, Dodge, Faribault, Freeborn, Jackson and 6 more	5 hr
Apr 18, 6:35 PM CDT	Tornado Watch	SPC	Brown, Carver, Dakota, Goodhue, Hennepin, Le Sueur and 7 more	5 hr
Apr 18, 1:42 PM CDT	Mesoscale Discussion	SPC	Arthur, Blaine, Boyd, Brown, Cherry, Grant and 10 more	3 hr

Nearby

Mesoscale Discussions in South Dakota, 2004 Mesoscale Discussions in Nebraska, 2004 Mesoscale Discussions in Minnesota, 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.