Alert archive / Texas / Mesoscale Discussions in 2019

Mesoscale Discussion 666

May 18, 201917 counties in Oklahoma; 32 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 18, 2019, 6:51 AM CDT for 17 counties in Oklahoma; 32 counties in Texas. It was in force for 114 min.

The area

The outline as issued.

The facts

Issued: May 18, 2019, 6:51 AM CDT (11:51 UTC)
Expired: May 18, 2019, 8:45 AM CDT
In force: 114 min
Issued by: the Storm Prediction Center

All 49 counties

Carter County, OK, Cleveland County, OK, Coal County, OK, Cotton County, OK, Garvin County, OK, Grady County, OK, Hughes County, OK, Jefferson County, OK, Johnston County, OK, Love County, OK, Marshall County, OK, McClain County, OK, Murray County, OK, Pontotoc County, OK, Pottawatomie County, OK, Seminole County, OK, Stephens County, OK, Archer County, TX, Baylor County, TX, Brown County, TX, Callahan County, TX, Clay County, TX, Coke County, TX, Coleman County, TX, Comanche County, TX, Cooke County, TX, Denton County, TX, Eastland County, TX, Erath County, TX, Fisher County, TX, Grayson County, TX, Haskell County, TX, Jack County, TX, Jones County, TX, Mitchell County, TX, Montague County, TX, Nolan County, TX, Palo Pinto County, TX, Parker County, TX, Runnels County, TX, Shackelford County, TX, Stephens County, TX, Sterling County, TX, Taylor County, TX, Throckmorton County, TX, Tom Green County, TX, Wichita County, TX, Wise County, TX, Young County, TX

The radar

The Dyess AFB radar (KDYX), 111 km from the middle of the area, began a volume at 11:53 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 181May 18, 9:10 AM CDT

The nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 11.9 hours before the alert went out and 126 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: 1123 J/kg
Mixed-layer CIN: -131 J/kg
Mixed-layer LCL: 1440 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 86 m²/s²
0-3 km storm-relative helicity: 204 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 3.6

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 17, 7:00 PM CDT	Mesoscale Discussion	SPC	Beaver	2 hr
May 18, 1:35 AM CDT	Mesoscale Discussion	SPC	Carter, Comanche, Cotton, Garvin, Grady, Jefferson and 2 more	2 hr
May 18, 2:20 AM CDT	Tornado Watch	SPC	Carter, Cleveland, Comanche, Cotton, Garvin, Grady and 9 more	8 hr
May 18, 5:11 AM CDT	Mesoscale Discussion	SPC	Carter, Comanche, Cotton, Garvin, Jefferson, Love and 3 more	2 hr
May 18, 7:47 AM CDT	Mesoscale Discussion	SPC	Alfalfa, Blaine, Caddo, Canadian, Cleveland, Creek and 18 more	88 min
May 18, 9:10 AM CDT	Tornado Watch	SPC	Adair, Atoka, Bryan, Cherokee, Choctaw, Coal and 27 more	8 hr
May 18, 9:38 AM CDT	Mesoscale Discussion	SPC	Craig, Creek, Delaware, Mayes, Nowata, Osage and 5 more	2 hr
May 18, 12:11 PM CDT	Mesoscale Discussion	SPC	Choctaw, Latimer, LeFlore, McCurtain, Pushmataha	64 min
May 18, 12:47 PM CDT	Mesoscale Discussion	SPC	Adair, Sequoyah	88 min
May 18, 12:48 PM CDT	Tornado Watch	SPC	McCurtain	7 hr
May 18, 3:31 PM CDT	Mesoscale Discussion	SPC	Alfalfa, Dewey, Ellis, Garfield, Grant, Harper and 3 more	119 min
May 18, 3:48 PM CDT	Severe Thunderstorm Watch	SPC	Alfalfa, Beaver, Blaine, Ellis, Garfield, Grant and 5 more	6 hr
May 18, 6:07 PM CDT	Mesoscale Discussion	SPC	Alfalfa, Beaver, Dewey, Ellis, Garfield, Grant and 6 more	83 min
May 17, 9:20 PM CDT	Mesoscale Discussion	SPC	Crockett, Irion, Reagan, Schleicher, Sutton, Terrell and 1 more	85 min
May 17, 11:47 PM CDT	Mesoscale Discussion	SPC	Borden, Brown, Callahan, Coke, Coleman, Concho and 34 more	2 hr
May 18, 1:16 PM CDT	Tornado Watch	SPC	Anderson, Bastrop, Bell, Blanco, Brazos, Burleson and 19 more	9 hr
May 18, 5:16 PM CDT	Mesoscale Discussion	SPC	Angelina, Grimes, Houston, Jasper, Nacogdoches, Newton and 9 more	119 min
May 18, 6:37 PM CDT	Mesoscale Discussion	SPC	Cooke, Dallas, Denton, Parker, Tarrant, Wise	53 min

Nearby

Mesoscale Discussions in Texas, 2019 Mesoscale Discussions in Oklahoma, 2019 Every mesoscale discussion in 2019

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.