Alert archive / Nebraska / Mesoscale Discussions in 2003

Mesoscale Discussion 1912

July 20, 20038 counties in Iowa; 20 counties in Nebraska; 9 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 20, 2003, 2:09 PM CDT for 8 counties in Iowa; 20 counties in Nebraska; 9 counties in South Dakota. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued: Jul 20, 2003, 2:09 PM CDT (19:09 UTC)
Expired: Jul 20, 2003, 3:15 PM CDT
In force: 66 min
Issued by: the Storm Prediction Center

All 37 counties

Crawford County, IA, Harrison County, IA, Monona County, IA, Plymouth County, IA, Pottawattamie County, IA, Shelby County, IA, Sioux County, IA, Woodbury County, IA, Antelope County, NE, Burt County, NE, Butler County, NE, Cedar County, NE, Colfax County, NE, Cuming County, NE, Dakota County, NE, Dixon County, NE, Dodge County, NE, Douglas County, NE, Knox County, NE, Madison County, NE, Pierce County, NE, Platte County, NE, Sarpy County, NE, Saunders County, NE, Stanton County, NE, Thurston County, NE, Washington County, NE, Wayne County, NE, Bon Homme County, SD, Charles Mix County, SD, Clay County, SD, Hutchinson County, SD, Lincoln County, SD, Minnehaha County, SD, Turner County, SD, Union County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 120 km from the middle of the area, began a volume at 19:11 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.

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 7.2 hours before the alert went out and 145 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: 1371 J/kg
Mixed-layer CIN: -314 J/kg
Mixed-layer LCL: 1243 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 67 m²/s²
0-3 km storm-relative helicity: 88 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

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
Jul 20, 4:14 AM CDT	Mesoscale Discussion	SPC	Howard, Mitchell, Winnebago, Winneshiek, Worth	3 hr
Jul 20, 6:45 AM CDT	Severe Thunderstorm Watch	SPC	Buena Vista, Butler, Calhoun, Cerro Gordo, Cherokee, Clay and 22 more	5 hr
Jul 20, 10:07 AM CDT	Mesoscale Discussion	SPC	Buena Vista, Calhoun, Cherokee, Clay, Dickinson, Emmet and 13 more	53 min
Jul 20, 2:50 PM CDT	Tornado Watch	SPC	Adair, Adams, Audubon, Buena Vista, Carroll, Cass and 20 more	6 hr
Jul 20, 5:29 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Audubon, Carroll, Cass, Cherokee and 17 more	91 min
Jul 20, 1:25 PM CDT	Mesoscale Discussion	SPC	Arthur, Blaine, Brown, Chase, Cheyenne, Custer and 13 more	95 min
Jul 20, 4:32 PM CDT	Mesoscale Discussion	SPC	Adams, Arthur, Boone, Buffalo, Chase, Cheyenne and 32 more	58 min
Jul 20, 4:50 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Boone, Buffalo, Butler, Chase, Clay and 35 more	4 hr
Jul 19, 11:58 PM CDT	Mesoscale Discussion	SPC	Brown, Clark, Codington, Day, Deuel, Edmunds and 6 more	62 min
Jul 20, 1:15 AM CDT	Severe Thunderstorm Watch	SPC	Aurora, Beadle, Brookings, Brown, Brule, Buffalo and 24 more	6 hr
Jul 20, 2:03 AM CDT	Mesoscale Discussion	SPC	Brookings, Brown, Campbell, Clark, Codington, Day and 10 more	117 min
Jul 20, 5:14 PM CDT	Mesoscale Discussion	SPC	Aurora, Brookings, Brule, Charles Mix, Davison, Douglas and 14 more	2 hr

Nearby

Mesoscale Discussions in Nebraska, 2003 Mesoscale Discussions in South Dakota, 2003 Mesoscale Discussions in Iowa, 2003 Every mesoscale discussion in 2003

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.