Alert archive / Oklahoma / Mesoscale Discussions in 2017

Mesoscale Discussion 890

May 27, 2017Crawford County, Sebastian County, Washington County, Arkansas; 23 counties in Oklahoma; 7 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 27, 2017, 11:47 PM CDT for Crawford County, Sebastian County, Washington County, Arkansas; 23 counties in Oklahoma; 7 counties in Texas. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued: May 27, 2017, 11:47 PM CDT (04:47 UTC)
Expired: May 28, 2017, 12:45 AM CDT
In force: 58 min
Issued by: the Storm Prediction Center

All 33 counties

Crawford County, AR, Sebastian County, AR, Washington County, AR, Adair County, OK, Atoka County, OK, Bryan County, OK, Carter County, OK, Cherokee County, OK, Choctaw County, OK, Coal County, OK, Garvin County, OK, Haskell County, OK, Hughes County, OK, Jefferson County, OK, Johnston County, OK, Latimer County, OK, LeFlore County, OK, Love County, OK, Marshall County, OK, McIntosh County, OK, Murray County, OK, Muskogee County, OK, Pittsburg County, OK, Pontotoc County, OK, Pushmataha County, OK, Sequoyah County, OK, Clay County, TX, Cooke County, TX, Fannin County, TX, Grayson County, TX, Lamar County, TX, Montague County, TX, Wichita County, TX

The radar

The Norman radar (KTLX), 114 km from the middle of the area, began a volume at 04:48 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.

Severe Thunderstorm Watch 289May 28, 12:05 AM CDT

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 4.8 hours before the alert went out and 111 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: 5174 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 1475 m above ground
0-6 km bulk shear: 56 kt
0-1 km storm-relative helicity: 91 m²/s²
0-3 km storm-relative helicity: 119 m²/s²
Significant tornado parameter: 1.2
Supercell composite: 8.1

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 27, 7:01 PM CDT	Tornado Watch	SPC	Baxter, Boone, Clay, Cleburne, Conway, Craighead and 20 more	6 hr
May 27, 9:26 PM CDT	Mesoscale Discussion	SPC	Clay, Craighead, Crittenden, Cross, Greene, Independence and 8 more	94 min
May 27, 9:59 PM CDT	Tornado Watch	SPC	Crittenden, Cross, Lee, St. Francis	2 hr
May 28, 12:06 AM CDT	Severe Thunderstorm Watch	SPC	Benton, Carroll, Columbia, Crawford, Franklin, Hempstead and 10 more	5 hr
May 28, 12:18 AM CDT	Severe Thunderstorm Watch	SPC	Arkansas, Bradley, Calhoun, Clark, Cleburne, Cleveland and 36 more	6 hr
May 28, 12:52 AM CDT	Mesoscale Discussion	SPC	Howard, Montgomery, Polk	23 min
May 28, 2:11 AM CDT	Mesoscale Discussion	SPC	Arkansas, Clark, Cleveland, Dallas, Desha, Faulkner and 12 more	2 hr
May 28, 2:53 AM CDT	Mesoscale Discussion	SPC	Columbia, Hempstead, Howard, Lafayette, Little River, Miller and 6 more	2 hr
May 28, 4:59 AM CDT	Mesoscale Discussion	SPC	Ashley, Bradley, Calhoun, Chicot, Cleveland, Columbia and 9 more	2 hr
May 27, 7:12 PM CDT	Mesoscale Discussion	SPC	Beaver, Cimarron, Texas	2 hr
May 27, 8:07 PM CDT	Mesoscale Discussion	SPC	Caddo, Canadian, Carter, Cherokee, Cleveland, Coal and 33 more	83 min
May 27, 9:07 PM CDT	Mesoscale Discussion	SPC	Beaver, Dewey, Ellis, Harper, Roger Mills, Woodward	53 min
May 27, 9:39 PM CDT	Severe Thunderstorm Watch	SPC	Beckham, Blaine, Custer, Dewey, Ellis, Garfield and 9 more	4 hr
May 27, 10:43 PM CDT	Mesoscale Discussion	SPC	Kingfisher, Major, Woodward	32 min
May 28, 1:34 PM CDT	Mesoscale Discussion	SPC	Bastrop, Bell, Bexar, Blanco, Burnet, Caldwell and 18 more	56 min
May 28, 3:09 PM CDT	Severe Thunderstorm Watch	SPC	Anderson, Atascosa, Austin, Bandera, Bastrop, Bell and 58 more	8 hr
May 28, 5:01 PM CDT	Mesoscale Discussion	SPC	Gregg, Harrison, Marion, Nacogdoches, Panola, Rusk and 1 more	59 min
May 28, 5:19 PM CDT	Severe Thunderstorm Watch	SPC	Angelina, Cherokee, Gregg, Harrison, Marion, Nacogdoches and 6 more	4 hr
May 28, 6:03 PM CDT	Mesoscale Discussion	SPC	Anderson, Bandera, Bastrop, Bell, Bexar, Blanco and 40 more	57 min

Nearby

Mesoscale Discussions in Oklahoma, 2017 Mesoscale Discussions in Texas, 2017 Mesoscale Discussions in Arkansas, 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.