Alert archive / Iowa / Mesoscale Discussions in 2007

Mesoscale Discussion 1533

July 18, 20074 states

The Storm Prediction Center issued this mesoscale discussion at Jul 18, 2007, 10:23 PM CDT for 4 states. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued: Jul 18, 2007, 10:23 PM CDT (03:23 UTC)
Expired: Jul 19, 2007, 12:00 AM CDT
In force: 97 min
Issued by: the Storm Prediction Center

All 81 counties

Adair County, IA, Adams County, IA, Appanoose County, IA, Audubon County, IA, Benton County, IA, Black Hawk County, IA, Boone County, IA, Buchanan County, IA, Buena Vista County, IA, Butler County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Cedar County, IA, Cherokee County, IA, Clarke County, IA, Crawford County, IA, Dallas County, IA, Davis County, IA, Delaware County, IA, Des Moines County, IA, Franklin County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hardin County, IA, Harrison County, IA, Henry County, IA, Humboldt County, IA, Ida County, IA, Iowa County, IA, Jasper County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Linn County, IA, Louisa County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Monona County, IA, Monroe County, IA, Montgomery County, IA, Muscatine County, IA, Plymouth County, IA, Pocahontas County, IA, Polk County, IA, Pottawattamie County, IA, Poweshiek County, IA, Sac County, IA, Scott County, IA, Shelby County, IA, Story County, IA, Tama County, IA, Union County, IA, Van Buren County, IA, Wapello County, IA, Warren County, IA, Washington County, IA, Webster County, IA, Woodbury County, IA, Wright County, IA, Mercer County, IL, Rock Island County, IL, Burt County, NE, Cedar County, NE, Cuming County, NE, Dakota County, NE, Dixon County, NE, Dodge County, NE, Knox County, NE, Pierce County, NE, Stanton County, NE, Thurston County, NE, Washington County, NE, Wayne County, NE, Union County, SD

The radar

The Des Moines radar (KDMX), 30 km from the middle of the area, began a volume at 03:27 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, 3.4 hours before the alert went out and 208 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: 2155 J/kg
Mixed-layer CIN: -38 J/kg
Mixed-layer LCL: 2120 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 15 m²/s²
0-3 km storm-relative helicity: 69 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 4.1

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
Jul 18, 7:29 PM CDT	Severe Thunderstorm Watch	SPC	Cook, DuPage, Ford, Grundy, Iroquois, Kane and 5 more	7 hr
Jul 18, 9:06 PM CDT	Mesoscale Discussion	SPC	Bureau, Carroll, Champaign, Coles, Cook, DeKalb and 38 more	84 min
Jul 18, 11:07 PM CDT	Severe Thunderstorm Watch	SPC	Bureau, Hancock, Henderson, Henry, McDonough, Mercer and 4 more	4 hr
Jul 19, 1:27 PM CDT	Mesoscale Discussion	SPC	Bond, Calhoun, Clark, Clay, Clinton, Coles and 26 more	93 min
Jul 19, 1:42 PM CDT	Severe Thunderstorm Watch	SPC	Bond, Calhoun, Clay, Clinton, Crawford, Edwards and 30 more	6 hr
Jul 19, 5:38 PM CDT	Mesoscale Discussion	SPC	Clinton, Edwards, Franklin, Gallatin, Hamilton, Hardin and 17 more	97 min
Jul 18, 8:39 PM CDT	Severe Thunderstorm Watch	SPC	Buena Vista, Cherokee, Ida, Monona, Plymouth, Woodbury	7 hr
Jul 18, 10:39 PM CDT	Severe Thunderstorm Watch	SPC	Adair, Audubon, Black Hawk, Boone, Calhoun, Carroll and 23 more	5 hr
Jul 19, 1:41 AM CDT	Mesoscale Discussion	SPC	Adair, Audubon, Black Hawk, Boone, Calhoun, Carroll and 23 more	94 min
Jul 18, 7:15 PM CDT	Mesoscale Discussion	SPC	Adams, Antelope, Arthur, Blaine, Boone, Box Butte and 45 more	90 min

Nearby

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