Alert archive / Iowa / Mesoscale Discussions in 2015

Mesoscale Discussion 1939

November 11, 201530 counties in Iowa; 19 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Nov 11, 2015, 1:42 PM CST for 30 counties in Iowa; 19 counties in Missouri. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued: Nov 11, 2015, 1:42 PM CST (19:42 UTC)
Expired: Nov 11, 2015, 3:15 PM CST
In force: 93 min
Issued by: the Storm Prediction Center

All 49 counties

Adair County, IA, Adams County, IA, Appanoose County, IA, Audubon County, IA, Boone County, IA, Carroll County, IA, Cass County, IA, Clarke County, IA, Dallas County, IA, Davis County, IA, Decatur County, IA, Greene County, IA, Guthrie County, IA, Jasper County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Monroe County, IA, Montgomery County, IA, Page County, IA, Polk County, IA, Ringgold County, IA, Shelby County, IA, Story County, IA, Taylor County, IA, Union County, IA, Wapello County, IA, Warren County, IA, Wayne County, IA, Adair County, MO, Caldwell County, MO, Carroll County, MO, Chariton County, MO, Clinton County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Grundy County, MO, Harrison County, MO, Linn County, MO, Livingston County, MO, Mercer County, MO, Nodaway County, MO, Putnam County, MO, Ray County, MO, Schuyler County, MO, Sullivan County, MO, Worth County, MO

The radar

The Des Moines radar (KDMX), 104 km from the middle of the area, began a volume at 19:44 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 535Nov 11, 3:20 PM CST

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 7.7 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 832 m above ground
0-6 km bulk shear: 68 kt
0-1 km storm-relative helicity: 140 m²/s²
0-3 km storm-relative helicity: 181 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
Nov 11, 10:17 AM CST	Mesoscale Discussion	SPC	Adair, Adams, Appanoose, Audubon, Benton, Black Hawk and 54 more	118 min
Nov 11, 11:25 AM CST	Tornado Watch	SPC	Adair, Adams, Appanoose, Audubon, Black Hawk, Boone and 41 more	6 hr
Nov 11, 12:38 PM CST	Mesoscale Discussion	SPC	Crawford, Harrison	67 min
Nov 11, 2:24 PM CST	Mesoscale Discussion	SPC	Benton, Cedar, Clinton, Des Moines, Henry, Iowa and 10 more	2 hr
Nov 11, 3:20 PM CST	Tornado Watch	SPC	Benton, Buchanan, Cedar, Clinton, Delaware, Des Moines and 15 more	6 hr
Nov 11, 4:59 PM CST	Mesoscale Discussion	SPC	Allamakee, Clayton	91 min

Nearby

Mesoscale Discussions in Iowa, 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.