Alert archive / Iowa / Mesoscale Discussions in 2015

Mesoscale Discussion 584

May 10, 20154 states

The Storm Prediction Center issued this mesoscale discussion at May 10, 2015, 10:24 AM CDT for 4 states. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: May 10, 2015, 10:24 AM CDT (15:24 UTC)
Expired: May 10, 2015, 1:00 PM CDT
In force: 3 hr
Issued by: the Storm Prediction Center
Chance of a watch: 80%

All 53 counties

Audubon County, IA, Buena Vista County, IA, Calhoun County, IA, Carroll County, IA, Cherokee County, IA, Clay County, IA, Crawford County, IA, Dickinson County, IA, Harrison County, IA, Ida County, IA, Lyon County, IA, Monona County, IA, O'Brien County, IA, Osceola County, IA, Palo Alto County, IA, Plymouth County, IA, Pocahontas County, IA, Pottawattamie County, IA, Sac County, IA, Shelby County, IA, Sioux County, IA, Woodbury County, IA, Jackson County, MN, Nobles County, MN, Rock County, MN, Burt County, NE, Cedar County, NE, Colfax County, NE, Cuming County, NE, Dakota County, NE, Dixon County, NE, Dodge County, NE, Douglas County, NE, Knox County, NE, Pierce County, NE, Sarpy County, NE, Saunders County, NE, Stanton County, NE, Thurston County, NE, Washington County, NE, Wayne County, NE, Bon Homme County, SD, Clay County, SD, Douglas County, SD, Hanson County, SD, Hutchinson County, SD, Lake County, SD, Lincoln County, SD, McCook County, SD, Minnehaha County, SD, Turner County, SD, Union County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 102 km from the middle of the area, began a volume at 15:25 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.

Tornado Watch 156May 10, 10:45 AM CDT

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 3.4 hours before the alert went out and 154 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: 460 J/kg
Mixed-layer CIN: -103 J/kg
Mixed-layer LCL: 625 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 158 m²/s²
0-3 km storm-relative helicity: 186 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 0.9

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
May 10, 10:46 AM CDT	Tornado Watch	SPC	Adair, Audubon, Buena Vista, Calhoun, Carroll, Cass and 21 more	8 hr
May 10, 11:52 AM CDT	Mesoscale Discussion	SPC	Adams, Decatur, Fremont, Page, Ringgold, Taylor	2 hr
May 10, 1:47 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Fremont, Mills, Montgomery, Page, Ringgold and 2 more	8 hr
May 10, 2:43 PM CDT	Mesoscale Discussion	SPC	Adams, Audubon, Buena Vista, Cass, Cherokee, Crawford and 11 more	92 min
May 10, 3:13 PM CDT	Mesoscale Discussion	SPC	Page	92 min
May 10, 5:17 PM CDT	Mesoscale Discussion	SPC	Cedar, Clinton, Des Moines, Henry, Iowa, Jackson and 9 more	88 min

Nearby

Mesoscale Discussions in Iowa, 2015 Mesoscale Discussions in Nebraska, 2015 Mesoscale Discussions in South Dakota, 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.