Alert archive / Iowa / Mesoscale Discussions in 2014

Mesoscale Discussion 576

May 11, 201446 counties in Iowa

The Storm Prediction Center issued this mesoscale discussion at May 11, 2014, 11:01 PM CDT for 46 counties in Iowa. It was in force for 59 min.

The area

The outline as issued.

The facts

Issued: May 11, 2014, 11:01 PM CDT (04:01 UTC)
Expired: May 12, 2014, 12:00 AM CDT
In force: 59 min
Issued by: the Storm Prediction Center

All 46 counties

Adair County, IA, Adams County, IA, Appanoose County, IA, Audubon County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Buena Vista County, IA, Butler County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Clarke County, IA, Dallas County, IA, Davis County, IA, Decatur County, IA, Franklin County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hardin County, IA, Humboldt County, IA, Jasper County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Monroe County, IA, Montgomery County, IA, Page County, IA, Pocahontas County, IA, Polk County, IA, Poweshiek County, IA, Ringgold County, IA, Sac County, IA, Story County, IA, Tama County, IA, Taylor County, IA, Union County, IA, Wapello County, IA, Warren County, IA, Wayne County, IA, Webster County, IA, Wright County, IA

The radar

The Des Moines radar (KDMX), 34 km from the middle of the area, began a volume at 04:03 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 00:00Z, 4.0 hours before the alert went out and 198 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: 2520 J/kg
Mixed-layer CIN: -40 J/kg
Mixed-layer LCL: 967 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 274 m²/s²
0-3 km storm-relative helicity: 254 m²/s²
Significant tornado parameter: 4.5
Supercell composite: 18.8

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 11, 7:04 PM CDT	Mesoscale Discussion	SPC	Adair, Audubon, Boone, Calhoun, Carroll, Clarke and 21 more	56 min
May 11, 7:49 PM CDT	Tornado Watch	SPC	Adair, Adams, Appanoose, Audubon, Black Hawk, Boone and 38 more	7 hr
May 11, 9:31 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Audubon, Boone, Buena Vista, Calhoun and 31 more	59 min
May 11, 9:56 PM CDT	Severe Thunderstorm Watch	SPC	Fremont, Mills, Montgomery, Page	6 hr
May 12, 11:54 AM CDT	Mesoscale Discussion	SPC	Appanoose, Benton, Cedar, Clarke, Clinton, Davis and 31 more	2 hr
May 12, 1:00 PM CDT	Severe Thunderstorm Watch	SPC	Appanoose, Benton, Black Hawk, Buchanan, Cedar, Clinton and 27 more	7 hr
May 12, 3:21 PM CDT	Mesoscale Discussion	SPC	Appanoose, Benton, Black Hawk, Buchanan, Cedar, Clinton and 23 more	54 min
May 12, 3:49 PM CDT	Severe Thunderstorm Watch	SPC	Clayton	7 hr
May 12, 6:56 PM CDT	Mesoscale Discussion	SPC	Jackson	64 min

Nearby

Mesoscale Discussions in Iowa, 2014 Every mesoscale discussion in 2014

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.