Alert archive / Oklahoma / Mesoscale Discussions in 2017

Mesoscale Discussion 760

May 18, 201712 counties in Oklahoma; 6 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 18, 2017, 3:02 PM CDT for 12 counties in Oklahoma; 6 counties in Texas. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued: May 18, 2017, 3:02 PM CDT (20:02 UTC)
Expired: May 18, 2017, 4:30 PM CDT
In force: 88 min
Issued by: the Storm Prediction Center

Counties Beckham County, OK, Caddo County, OK, Comanche County, OK, Cotton County, OK, Grady County, OK, Greer County, OK, Harmon County, OK, Jackson County, OK, Kiowa County, OK, Stephens County, OK, Tillman County, OK, Washita County, OK, Baylor County, TX, Foard County, TX, Hardeman County, TX, Knox County, TX, Wichita County, TX, Wilbarger County, TX

The radar

The Altus AFB radar (KFDR), 39 km from the middle of the area, began a volume at 20:04 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 12:00Z, 8.0 hours before the alert went out and 158 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: 1272 J/kg
Mixed-layer CIN: -210 J/kg
Mixed-layer LCL: 1122 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 231 m²/s²
0-3 km storm-relative helicity: 250 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.9

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 18, 12:59 PM CDT	Mesoscale Discussion	SPC	Alfalfa, Beckham, Blaine, Caddo, Comanche, Cotton and 14 more	2 hr
May 18, 1:18 PM CDT	Tornado Watch PDS	SPC	Alfalfa, Beckham, Blaine, Caddo, Canadian, Carter and 31 more	7 hr
May 18, 5:15 PM CDT	Mesoscale Discussion	SPC	Alfalfa, Blaine, Garfield, Grant, Kingfisher, Major and 1 more	60 min
May 18, 5:47 PM CDT	Mesoscale Discussion	SPC	Craig, Creek, Hughes, Lincoln, Mayes, Nowata and 10 more	28 min
May 18, 6:02 PM CDT	Tornado Watch	SPC	Adair, Cherokee, Coal, Craig, Creek, Delaware and 26 more	7 hr
May 18, 12:03 PM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Brown, Callahan, Clay, Coke and 37 more	117 min
May 18, 1:55 PM CDT	Tornado Watch	SPC	Bosque, Brown, Callahan, Coke, Coleman, Collin and 40 more	10 hr
May 18, 4:55 PM CDT	Mesoscale Discussion	SPC	Bosque, Brown, Callahan, Coke, Coleman, Collin and 39 more	95 min

Nearby

Mesoscale Discussions in Oklahoma, 2017 Mesoscale Discussions in Texas, 2017 Every mesoscale discussion in 2017

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.