Alert archive / Nebraska / Mesoscale Discussions in 2003

Mesoscale Discussion 1923

July 20, 200323 counties in Iowa; 32 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Jul 20, 2003, 7:49 PM CDT for 23 counties in Iowa; 32 counties in Nebraska. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued
Jul 20, 2003, 7:49 PM CDT (00:49 UTC)
Expired
Jul 20, 2003, 8:45 PM CDT
In force
56 min
Issued by
the Storm Prediction Center
All 55 counties

Adair County, IA, Adams County, IA, Audubon County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Crawford County, IA, Dallas County, IA, Fremont County, IA, Greene County, IA, Guthrie County, IA, Harrison County, IA, Ida County, IA, Madison County, IA, Mills County, IA, Monona County, IA, Montgomery County, IA, Page County, IA, Pocahontas County, IA, Pottawattamie County, IA, Sac County, IA, Shelby County, IA, Union County, IA, Adams County, NE, Burt County, NE, Butler County, NE, Cass County, NE, Clay County, NE, Colfax County, NE, Cuming County, NE, Dodge County, NE, Douglas County, NE, Fillmore County, NE, Gage County, NE, Hall County, NE, Hamilton County, NE, Howard County, NE, Jefferson County, NE, Johnson County, NE, Lancaster County, NE, Merrick County, NE, Nance County, NE, Otoe County, NE, Platte County, NE, Polk County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Sherman County, NE, Stanton County, NE, Thayer County, NE, Thurston County, NE, Washington County, NE, York County, NE

The radar

The Omaha radar (KOAX), 41 km from the middle of the area, began a volume at 00:52 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 00:00Z, 0.8 hours before the alert went out and 41 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, Omaha, NE at 00:00Z on 2003-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4827 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, Omaha, NE at 00:00Z on 2003-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 92 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
4827 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
1616 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
92 m²/s²
0-3 km storm-relative helicity
162 m²/s²
Significant tornado parameter
1.4
Supercell composite
28.6

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 20, 8:08 PM CDTMesoscale DiscussionSPCAppanoose, Benton, Black Hawk, Bremer, Buchanan, Cedar and 38 more2 hr
Jul 20, 8:30 PM CDTTornado WatchSPCAllamakee, Appanoose, Benton, Black Hawk, Bremer, Buchanan and 42 more6 hr
Jul 20, 8:50 PM CDTTornado WatchSPCAdair, Adams, Audubon, Boone, Carroll, Cass and 16 more5 hr
Jul 20, 11:14 PM CDTMesoscale DiscussionSPCAppanoose, Benton, Cedar, Clinton, Davis, Delaware and 20 more2 hr
Jul 20, 11:30 PM CDTSevere Thunderstorm WatchSPCLee6 hr
Jul 20, 7:03 PM CDTMesoscale DiscussionSPCAdams, Boone, Buffalo, Chase, Clay, Custer and 27 more87 min
Jul 20, 10:43 PM CDTMesoscale DiscussionSPCNuckolls, Richardson62 min
Jul 21, 2:24 PM CDTMesoscale DiscussionSPCChase, Dawson, Deuel, Dundy, Frontier, Furnas and 9 more66 min
Jul 21, 4:50 PM CDTTornado WatchSPCArthur, Blaine, Chase, Dawson, Deuel, Dundy and 15 more5 hr

Nearby

Mesoscale Discussions in Nebraska, 2003Mesoscale Discussions in Iowa, 2003Every 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.