Alert archive / Iowa / Mesoscale Discussions in 2015

Mesoscale Discussion 1564

July 28, 201531 counties in Iowa; 8 counties in Missouri; 10 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Jul 28, 2015, 3:40 PM CDT for 31 counties in Iowa; 8 counties in Missouri; 10 counties in Nebraska. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jul 28, 2015, 3:40 PM CDT (20:40 UTC)
Expired: Jul 28, 2015, 5:45 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 60%

All 49 counties

Adair County, IA, Adams County, IA, Appanoose County, IA, Audubon County, IA, Cass County, IA, Clarke County, IA, Dallas County, IA, Davis County, IA, Decatur County, IA, Fremont County, IA, Guthrie County, IA, Jasper County, IA, Jefferson County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Mills County, IA, Monroe County, IA, Montgomery County, IA, Page County, IA, Polk County, IA, Pottawattamie County, IA, Ringgold County, IA, Shelby County, IA, Taylor County, IA, Union County, IA, Van Buren County, IA, Wapello County, IA, Warren County, IA, Wayne County, IA, Atchison County, MO, Harrison County, MO, Holt County, MO, Mercer County, MO, Nodaway County, MO, Putnam County, MO, Schuyler County, MO, Worth County, MO, Cass County, NE, Douglas County, NE, Gage County, NE, Johnson County, NE, Lancaster County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Richardson County, NE, Sarpy County, NE

The radar

The Des Moines radar (KDMX), 134 km from the middle of the area, began a volume at 20:42 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.

Severe Thunderstorm Watch 459Jul 28, 5:45 PM CDT

The nearest sounding before it

Topeka, KS (KFOE), launched 12:00Z, 8.7 hours before the alert went out and 215 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: 721 J/kg
Mixed-layer CIN: -285 J/kg
Mixed-layer LCL: 1383 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: -51 m²/s²
0-3 km storm-relative helicity: -37 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.

Issued	Product	Office	Counties	Lasted
Jul 28, 1:57 AM CDT	Mesoscale Discussion	SPC	Lyon, Sioux	2 hr
Jul 28, 3:37 AM CDT	Mesoscale Discussion	SPC	Dickinson, Lyon, O'Brien, Osceola, Plymouth, Sioux	2 hr
Jul 28, 5:46 PM CDT	Severe Thunderstorm Watch	SPC	Adair, Adams, Appanoose, Cass, Clarke, Davis and 28 more	6 hr
Jul 28, 4:50 PM CDT	Mesoscale Discussion	SPC	Buchanan	2 hr
Jul 27, 9:41 PM CDT	Mesoscale Discussion	SPC	Boyd	3 hr
Jul 28, 12:38 AM CDT	Mesoscale Discussion	SPC	Arthur, Blaine, Brown, Custer, Garfield, Grant and 8 more	3 hr

Nearby

Mesoscale Discussions in Iowa, 2015 Mesoscale Discussions in Nebraska, 2015 Mesoscale Discussions in Missouri, 2015 Every mesoscale discussion in 2015

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.