Alert archive / Iowa / Mesoscale Discussions in 2005

Mesoscale Discussion 600

April 19, 200533 counties in Iowa; 28 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Apr 19, 2005, 7:38 PM CDT for 33 counties in Iowa; 28 counties in Nebraska. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 19, 2005, 7:38 PM CDT (00:38 UTC)
Expired
Apr 19, 2005, 9:45 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 61 counties

Adair County, IA, Audubon County, IA, Boone County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Crawford County, IA, Dallas County, IA, Franklin County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hardin County, IA, Harrison County, IA, Ida County, IA, Jasper County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Monona County, IA, Pocahontas County, IA, Polk County, IA, Pottawattamie 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, Antelope County, NE, Boone County, NE, Burt County, NE, Butler County, NE, Colfax County, NE, Cuming County, NE, Dakota County, NE, Dixon County, NE, Dodge County, NE, Douglas County, NE, Garfield County, NE, Greeley County, NE, Howard County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Pierce County, NE, Platte County, NE, Polk County, NE, Sarpy County, NE, Saunders County, NE, Sherman County, NE, Stanton County, NE, Thurston County, NE, Valley County, NE, Washington County, NE, Wayne County, NE, Wheeler County, NE

The radar

The Des Moines radar (KDMX), 121 km from the middle of the area, began a volume at 00:41 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, 0.6 hours before the alert went out and 124 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 2005-04-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1217 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 2005-04-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 22 square meters per square second.1939Sfc1 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
1217 J/kg
Mixed-layer CIN
-13 J/kg
Mixed-layer LCL
1628 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
22 m²/s²
0-3 km storm-relative helicity
74 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.7

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
Apr 20, 1:14 AM CDTMesoscale DiscussionSPCHarrison, Monona, Woodbury2 hr
Apr 20, 1:18 AM CDTMesoscale DiscussionSPCHarrison, Monona, Woodbury117 min
Apr 19, 7:21 PM CDTMesoscale DiscussionSPCArthur, Banner, Box Butte, Brown, Chase, Cherry and 16 more114 min
Apr 19, 9:30 PM CDTSevere Thunderstorm WatchSPCBlaine, Brown, Buffalo, Custer, Dawson, Garfield and 14 more8 hr
Apr 19, 10:56 PM CDTMesoscale DiscussionSPCAntelope, Blaine, Boyd, Brown, Buffalo, Cedar and 23 more94 min
Apr 20, 6:23 PM CDTMesoscale DiscussionSPCBanner, Box Butte, Cheyenne, Dawes, Deuel, Garden and 4 more97 min

Nearby

Mesoscale Discussions in Iowa, 2005Mesoscale Discussions in Nebraska, 2005Every mesoscale discussion in 2005

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.