Alert archive / Nebraska / Mesoscale Discussions in 2007

Mesoscale Discussion 1737

August 12, 20074 states

The Storm Prediction Center issued this mesoscale discussion at Aug 12, 2007, 2:52 PM CDT for 4 states. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued
Aug 12, 2007, 2:52 PM CDT (19:52 UTC)
Expired
Aug 12, 2007, 4:15 PM CDT
In force
83 min
Issued by
the Storm Prediction Center
All 64 counties

Adair County, IA, Adams County, IA, Audubon County, IA, Cass County, IA, Clarke County, IA, Decatur County, IA, Fremont County, IA, Harrison County, IA, Madison County, IA, Mills County, IA, Montgomery County, IA, Page County, IA, Pottawattamie County, IA, Ringgold County, IA, Shelby County, IA, Taylor County, IA, Union County, IA, Wayne County, IA, Brown County, KS, Doniphan County, KS, Andrew County, MO, Atchison County, MO, Buchanan County, MO, Clinton County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Grundy County, MO, Harrison County, MO, Holt County, MO, Mercer County, MO, Nodaway County, MO, Sullivan County, MO, Worth County, MO, 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, Jefferson County, NE, Johnson County, NE, Lancaster County, NE, Merrick County, NE, Nance County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Platte County, NE, Polk County, NE, Richardson County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Washington County, NE, York County, NE

The radar

The Omaha radar (KOAX), 69 km from the middle of the area, began a volume at 19:53 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, 7.9 hours before the alert went out and 69 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 2007-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3259 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 2007-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 64 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
3259 J/kg
Mixed-layer CIN
-153 J/kg
Mixed-layer LCL
1117 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
64 m²/s²
0-3 km storm-relative helicity
89 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.1

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
Aug 11, 9:43 PM CDTMesoscale DiscussionSPCAllamakee, Bremer, Buchanan, Chickasaw, Clayton, Delaware and 3 more92 min
Aug 11, 9:57 PM CDTSevere Thunderstorm WatchSPCAllamakee, Howard, Mitchell, Winneshiek5 hr
Aug 11, 11:46 PM CDTMesoscale DiscussionSPCAllamakee, Howard, Mitchell, Winneshiek119 min
Aug 12, 1:20 AM CDTMesoscale DiscussionSPCJackson25 min
Aug 12, 3:56 PM CDTSevere Thunderstorm WatchSPCAdair, Adams, Appanoose, Audubon, Cass, Clarke and 16 more7 hr
Aug 12, 5:49 PM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Cass, Dallas, Guthrie and 9 more86 min
Aug 12, 11:20 AM CDTMesoscale DiscussionSPCAdams, Arthur, Buffalo, Butler, Cass, Chase and 38 more115 min
Aug 12, 1:57 PM CDTSevere Thunderstorm WatchSPCAdams, Antelope, Boone, Burt, Butler, Cass and 30 more6 hr

Nearby

Mesoscale Discussions in Nebraska, 2007Mesoscale Discussions in Iowa, 2007Mesoscale Discussions in Missouri, 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.