Alert archive / Iowa / Mesoscale Discussions in 2015

Mesoscale Discussion 1737

August 22, 20154 states

The Storm Prediction Center issued this mesoscale discussion at Aug 22, 2015, 6:21 PM CDT for 4 states. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued: Aug 22, 2015, 6:21 PM CDT (23:21 UTC)
Expired: Aug 22, 2015, 7:45 PM CDT
In force: 84 min
Issued by: the Storm Prediction Center

All 57 counties

Adair County, IA, Adams County, IA, Audubon County, IA, Carroll County, IA, Cass County, IA, Clarke County, IA, Dallas County, IA, Fremont County, IA, Greene County, IA, Guthrie County, IA, Madison County, IA, Mills 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, Warren County, IA, Atchison County, KS, Brown County, KS, Clay County, KS, Cloud County, KS, Doniphan County, KS, Geary County, KS, Jackson County, KS, Jefferson County, KS, Jewell County, KS, Marshall County, KS, Mitchell County, KS, Nemaha County, KS, Pottawatomie County, KS, Republic County, KS, Riley County, KS, Shawnee County, KS, Wabaunsee County, KS, Washington County, KS, Andrew County, MO, Atchison County, MO, Buchanan County, MO, Gentry County, MO, Holt County, MO, Nodaway County, MO, Worth County, MO, Cass County, NE, Gage County, NE, Jefferson County, NE, Johnson County, NE, Lancaster County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Richardson County, NE, Sarpy County, NE, Thayer County, NE

The radar

The Topeka radar (KTWX), 126 km from the middle of the area, began a volume at 23:22 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, 11.4 hours before the alert went out and 133 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: 1047 J/kg
Mixed-layer CIN: -293 J/kg
Mixed-layer LCL: 629 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 194 m²/s²
0-3 km storm-relative helicity: 157 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.6

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 22, 2:13 PM CDT	Mesoscale Discussion	SPC	Audubon, Boone, Buena Vista, Calhoun, Carroll, Cerro Gordo and 33 more	62 min
Aug 22, 2:35 PM CDT	Tornado Watch	SPC	Buena Vista, Calhoun, Cerro Gordo, Cherokee, Clay, Dickinson and 21 more	7 hr
Aug 22, 2:55 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Audubon, Boone, Carroll, Cass and 19 more	65 min
Aug 22, 3:48 PM CDT	Tornado Watch	SPC	Adair, Adams, Audubon, Boone, Carroll, Cass and 25 more	8 hr
Aug 22, 5:52 PM CDT	Mesoscale Discussion	SPC	Buena Vista, Cerro Gordo, Clay, Emmet, Franklin, Hamilton and 10 more	83 min
Aug 22, 6:12 PM CDT	Mesoscale Discussion	SPC	Allamakee, Bremer, Butler, Chickasaw, Clayton, Fayette and 4 more	63 min

Nearby

Mesoscale Discussions in Iowa, 2015 Mesoscale Discussions in Kansas, 2015 Mesoscale Discussions in Nebraska, 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.