Alert archive / Iowa / Mesoscale Discussions in 2007

Mesoscale Discussion 1738

August 12, 200715 counties in Iowa

The Storm Prediction Center issued this mesoscale discussion at Aug 12, 2007, 5:49 PM CDT for 15 counties in Iowa. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued: Aug 12, 2007, 5:49 PM CDT (22:49 UTC)
Expired: Aug 12, 2007, 7:15 PM CDT
In force: 86 min
Issued by: the Storm Prediction Center

Counties Adair County, IA, Adams County, IA, Audubon County, IA, Cass County, IA, Dallas County, IA, Guthrie 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

The radar

The Des Moines radar (KDMX), 103 km from the middle of the area, began a volume at 22:50 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, 10.8 hours before the alert went out and 131 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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.

Issued	Product	Office	Counties	Lasted
Aug 11, 9:43 PM CDT	Mesoscale Discussion	SPC	Allamakee, Bremer, Buchanan, Chickasaw, Clayton, Delaware and 3 more	92 min
Aug 11, 9:57 PM CDT	Severe Thunderstorm Watch	SPC	Allamakee, Howard, Mitchell, Winneshiek	5 hr
Aug 11, 11:46 PM CDT	Mesoscale Discussion	SPC	Allamakee, Howard, Mitchell, Winneshiek	119 min
Aug 12, 1:20 AM CDT	Mesoscale Discussion	SPC	Jackson	25 min
Aug 12, 2:52 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Audubon, Cass, Clarke, Decatur and 12 more	83 min
Aug 12, 3:56 PM CDT	Severe Thunderstorm Watch	SPC	Adair, Adams, Appanoose, Audubon, Cass, Clarke and 16 more	7 hr

Nearby

Mesoscale Discussions in Iowa, 2007 Every 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.