Alert archive / Iowa / Mesoscale Discussions in 2004

Mesoscale Discussion 601

May 8, 200439 counties in Iowa; 26 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at May 8, 2004, 5:45 PM CDT for 39 counties in Iowa; 26 counties in Nebraska. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 8, 2004, 5:45 PM CDT (22:45 UTC)
Expired
May 8, 2004, 7:45 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 65 counties

Adair County, IA, Adams County, IA, Audubon County, IA, Benton County, IA, Boone County, IA, Buena Vista County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Crawford County, IA, Dallas County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hardin County, IA, Harrison County, IA, Humboldt County, IA, Ida County, IA, Iowa County, IA, Jasper County, IA, Linn County, IA, Madison County, IA, Marshall County, IA, Mills County, IA, Monona County, IA, Montgomery County, IA, Pocahontas County, IA, Polk County, IA, Pottawattamie County, IA, Poweshiek County, IA, Sac County, IA, Shelby County, IA, Story County, IA, Tama County, IA, Warren County, IA, Webster County, IA, Woodbury County, IA, Wright County, IA, Boone County, NE, Burt County, NE, Butler County, NE, Cass County, NE, Colfax County, NE, Cuming County, NE, Dakota County, NE, Dodge County, NE, Douglas County, NE, Greeley County, NE, Hamilton County, NE, Howard County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Platte County, NE, Polk County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Stanton County, NE, Thurston County, NE, Valley County, NE, Washington County, NE, Wayne County, NE, York County, NE

The radar

The Omaha radar (KOAX), 110 km from the middle of the area, began a volume at 22:45 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, 10.8 hours before the alert went out and 110 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 12:00Z on 2004-05-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 902 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 12:00Z on 2004-05-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 248 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
902 J/kg
Mixed-layer CIN
-426 J/kg
Mixed-layer LCL
1108 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
248 m²/s²
0-3 km storm-relative helicity
227 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.

IssuedProductOfficeCountiesLasted
May 7, 8:20 PM CDTMesoscale DiscussionSPCAllamakee, Benton, Buchanan, Clayton, Delaware, Dubuque and 5 more85 min
May 7, 9:53 PM CDTMesoscale DiscussionSPCBuena Vista, Calhoun, Cerro Gordo, Cherokee, Clay, Crawford and 21 more97 min
May 7, 10:20 PM CDTSevere Thunderstorm WatchSPCBlack Hawk, Boone, Bremer, Buena Vista, Butler, Calhoun and 38 more6 hr
May 8, 12:26 AM CDTMesoscale DiscussionSPCAllamakee, Clayton, Winneshiek64 min
May 8, 12:50 AM CDTSevere Thunderstorm WatchSPCAllamakee, Winneshiek6 hr
May 8, 2:27 AM CDTMesoscale DiscussionSPCBlack Hawk, Boone, Bremer, Buena Vista, Butler, Calhoun and 27 more93 min
May 8, 3:36 AM CDTMesoscale DiscussionSPCAllamakee, Winneshiek54 min
May 8, 5:35 AM CDTMesoscale DiscussionSPCAllamakee, Winneshiek55 min
May 8, 2:27 PM CDTMesoscale DiscussionSPCAdair, Audubon, Black Hawk, Boone, Bremer, Buena Vista and 37 more3 hr
May 8, 3:45 PM CDTSevere Thunderstorm WatchSPCAudubon, Benton, Black Hawk, Boone, Bremer, Buchanan and 38 more5 hr
May 8, 4:50 PM CDTSevere Thunderstorm WatchSPCAdams, Buffalo, Butler, Clay, Dawson, Franklin and 14 more4 hr
May 8, 6:56 PM CDTMesoscale DiscussionSPCAdams, Buffalo, Clay, Hall, Hamilton, Howard and 5 more2 hr

Nearby

Mesoscale Discussions in Iowa, 2004Mesoscale Discussions in Nebraska, 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.