Alert archive / Iowa / Mesoscale Discussions in 2007

Mesoscale Discussion 541

April 22, 200712 counties in Iowa; 10 counties in Missouri; 5 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Apr 22, 2007, 5:59 PM CDT for 12 counties in Iowa; 10 counties in Missouri; 5 counties in South Dakota. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 22, 2007, 5:59 PM CDT (22:59 UTC)
Expired
Apr 22, 2007, 8:00 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 27 counties

Boone County, IA, Clarke County, IA, Dallas County, IA, Decatur County, IA, Dickinson County, IA, Humboldt County, IA, Lyon County, IA, Madison County, IA, Osceola County, IA, Ringgold County, IA, Sioux County, IA, Union County, IA, Caldwell County, MO, Clinton County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Grundy County, MO, Harrison County, MO, Livingston County, MO, Mercer County, MO, Worth County, MO, Bon Homme County, SD, Clay County, SD, Lincoln County, SD, Turner County, SD, Yankton County, SD

The radar

The Omaha radar (KOAX), 114 km from the middle of the area, began a volume at 23:01 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, 11.0 hours before the alert went out and 115 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 2007-04-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2007-04-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -53 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1189 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
-53 m²/s²
0-3 km storm-relative helicity
-25 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
Apr 22, 10:57 AM CDTMesoscale DiscussionSPCFremont, Mills, Page93 min
Apr 22, 12:07 PM CDTMesoscale DiscussionSPCAdair, Allamakee, Benton, Black Hawk, Boone, Bremer and 55 more113 min
Apr 22, 1:17 PM CDTSevere Thunderstorm WatchSPCAllamakee, Appanoose, Benton, Black Hawk, Bremer, Buchanan and 52 more8 hr
Apr 22, 1:25 PM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Buena Vista, Calhoun, Carroll and 26 more95 min
Apr 22, 1:56 PM CDTTornado WatchSPCAdair, Adams, Audubon, Boone, Buena Vista, Calhoun and 31 more7 hr
Apr 22, 6:36 PM CDTMesoscale DiscussionSPCAppanoose, Black Hawk, Bremer, Butler, Cerro Gordo, Chickasaw and 27 more114 min
Apr 22, 11:30 AM CDTTornado WatchSPCAtchison, Holt6 hr
Apr 22, 3:07 PM CDTMesoscale DiscussionSPCBarton, Bates, Cass, Clay, Jackson, Johnson and 4 more113 min
Apr 21, 7:56 PM CDTMesoscale DiscussionSPCAurora, Beadle, Brown, Brule, Buffalo, Campbell and 32 more2 hr
Apr 21, 8:16 PM CDTMesoscale DiscussionSPCAurora, Beadle, Brown, Brule, Buffalo, Campbell and 32 more119 min
Apr 21, 10:34 PM CDTSevere Thunderstorm WatchSPCAurora, Beadle, Bon Homme, Brookings, Brule, Charles Mix and 15 more3 hr

Nearby

Mesoscale Discussions in Iowa, 2007Mesoscale Discussions in Missouri, 2007Mesoscale Discussions in South Dakota, 2007Every mesoscale discussion in 2007

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.