Alert archive / Texas / Mesoscale Discussions in 2017

Mesoscale Discussion 771

May 18, 201716 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 18, 2017, 9:08 PM CDT for 16 counties in Texas. It was in force for 37 min.

The area

The outline as issued.

The facts

Issued: May 18, 2017, 9:08 PM CDT (02:08 UTC)
Expired: May 18, 2017, 9:45 PM CDT
In force: 37 min
Issued by: the Storm Prediction Center

Counties Brown County, TX, Clay County, TX, Comanche County, TX, Cooke County, TX, Denton County, TX, Eastland County, TX, Erath County, TX, Grayson County, TX, Hamilton County, TX, Jack County, TX, Montague County, TX, Palo Pinto County, TX, Parker County, TX, Stephens County, TX, Wise County, TX, Young County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 77 km from the middle of the area, began a volume at 02:12 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

Fort Worth, TX (KFWD), launched 00:00Z, 2.1 hours before the alert went out and 81 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: 1519 J/kg
Mixed-layer CIN: -36 J/kg
Mixed-layer LCL: 1729 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 154 m²/s²
0-3 km storm-relative helicity: 211 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 16.4

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, 7:47 PM CDT	Severe Thunderstorm Watch	SPC	Archer, Baylor, Clay, Wichita	6 hr
May 19, 2:17 AM CDT	Mesoscale Discussion	SPC	Callahan, Coke, Crane, Ector, Fisher, Glasscock and 9 more	118 min
May 19, 2:44 AM CDT	Severe Thunderstorm Watch	SPC	Callahan, Coke, Fisher, Glasscock, Haskell, Howard and 13 more	6 hr
May 19, 7:03 AM CDT	Mesoscale Discussion	SPC	Callahan, Collin, Dallas, Denton, Eastland, Ellis and 15 more	117 min
May 19, 10:41 AM CDT	Mesoscale Discussion	SPC	Archer, Clay, Cooke, Fisher, Haskell, Jack and 9 more	94 min
May 19, 12:26 PM CDT	Tornado Watch	SPC	Brown, Callahan, Coke, Coleman, Comanche, Concho and 19 more	7 hr
May 19, 2:45 PM CDT	Mesoscale Discussion	SPC	Callahan, Coke, Coleman, Concho, Fisher, Irion and 10 more	60 min
May 19, 3:26 PM CDT	Tornado Watch	SPC	Archer, Baylor, Bosque, Clay, Collin, Comanche and 28 more	11 hr
May 19, 5:50 PM CDT	Mesoscale Discussion	SPC	Brown, Callahan, Coke, Coleman, Concho, Eastland and 11 more	115 min
May 19, 6:56 PM CDT	Mesoscale Discussion	SPC	Archer, Bosque, Brown, Clay, Collin, Comanche and 28 more	2 hr

Nearby

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.