Alert archive / Oklahoma / Mesoscale Discussions in 2015

Mesoscale Discussion 287

April 12, 201511 counties in Kansas; 22 counties in Oklahoma; 11 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 12, 2015, 8:23 PM CDT for 11 counties in Kansas; 22 counties in Oklahoma; 11 counties in Texas. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued: Apr 12, 2015, 8:23 PM CDT (01:23 UTC)
Expired: Apr 12, 2015, 10:00 PM CDT
In force: 97 min
Issued by: the Storm Prediction Center

All 44 counties

Butler County, KS, Chase County, KS, Cowley County, KS, Harper County, KS, Harvey County, KS, Kingman County, KS, Marion County, KS, McPherson County, KS, Reno County, KS, Sedgwick County, KS, Sumner County, KS, Alfalfa County, OK, Beckham County, OK, Blaine County, OK, Caddo County, OK, Canadian County, OK, Comanche County, OK, Custer County, OK, Dewey County, OK, Garfield County, OK, Grant County, OK, Greer County, OK, Harmon County, OK, Jackson County, OK, Kay County, OK, Kingfisher County, OK, Kiowa County, OK, Logan County, OK, Major County, OK, Noble County, OK, Tillman County, OK, Washita County, OK, Woods County, OK, Baylor County, TX, Childress County, TX, Cottle County, TX, Dickens County, TX, Foard County, TX, Hall County, TX, Hardeman County, TX, King County, TX, Knox County, TX, Motley County, TX, Wilbarger County, TX

The radar

The Vance AFB radar (KVNX), 56 km from the middle of the area, began a volume at 01:27 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

Norman, OK (KOUN), launched 00:00Z, 1.4 hours before the alert went out and 162 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: 1094 J/kg
Mixed-layer CIN: -66 J/kg
Mixed-layer LCL: 999 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 104 m²/s²
0-3 km storm-relative helicity: 142 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 4.7

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
Apr 12, 8:59 PM CDT	Mesoscale Discussion	SPC	Atascosa, Bandera, Brooks, Dimmit, Duval, Frio and 12 more	91 min
Apr 13, 2:48 PM CDT	Mesoscale Discussion	SPC	Brown, Coke, Coleman, Mitchell, Nolan, Runnels	117 min
Apr 13, 3:55 PM CDT	Mesoscale Discussion	SPC	Brooks, Duval, Jim Hogg, Zapata	2 hr
Apr 13, 5:16 PM CDT	Mesoscale Discussion	SPC	Anderson, Bosque, Brown, Coke, Coleman, Comanche and 9 more	119 min
Apr 13, 5:33 PM CDT	Severe Thunderstorm Watch	SPC	Anderson, Bell, Bosque, Brown, Callahan, Coke and 22 more	4 hr

Nearby

Mesoscale Discussions in Oklahoma, 2015 Mesoscale Discussions in Kansas, 2015 Mesoscale Discussions in Texas, 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.