Alert archive / Texas / Mesoscale Discussions in 2015

Mesoscale Discussion 692

May 18, 201518 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 18, 2015, 8:00 PM CDT for 18 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: May 18, 2015, 8:00 PM CDT (01:00 UTC)
Expired: May 18, 2015, 10:00 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Bell County, TX, Blanco County, TX, Burnet County, TX, Concho County, TX, Coryell County, TX, Crockett County, TX, Gillespie County, TX, Kimble County, TX, Lampasas County, TX, Llano County, TX, Mason County, TX, McCulloch County, TX, Menard County, TX, Milam County, TX, San Saba County, TX, Schleicher County, TX, Sutton County, TX, Williamson County, TX

The radar

The Austin/San Antonio radar (KEWX), 146 km from the middle of the area, began a volume at 01:02 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

Del Rio, TX (KDLF), launched 00:00Z, 1.0 hours before the alert went out and 225 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: 2439 J/kg
Mixed-layer CIN: -16 J/kg
Mixed-layer LCL: 1242 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: -7 m²/s²
0-3 km storm-relative helicity: 9 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.4

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
May 18, 9:01 PM CDT	Mesoscale Discussion	SPC	Andrews, Cochran, Crane, Crockett, Ector, Gaines and 12 more	89 min
May 19, 12:53 AM CDT	Mesoscale Discussion	SPC	Bailey, Cochran, Parmer	97 min
May 19, 2:15 AM CDT	Mesoscale Discussion	SPC	Crockett, Irion, Reagan, Schleicher, Sutton, Tom Green	90 min
May 19, 5:13 AM CDT	Mesoscale Discussion	SPC	Armstrong, Bailey, Briscoe, Carson, Castro, Cochran and 16 more	92 min
May 19, 1:02 PM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Clay, Fisher, Foard, Hardeman and 12 more	118 min
May 19, 1:32 PM CDT	Tornado Watch	SPC	Archer, Baylor, Clay, Cooke, Foard, Hardeman and 4 more	7 hr
May 19, 2:30 PM CDT	Mesoscale Discussion	SPC	Bell, Bosque, Brown, Callahan, Coleman, Collin and 34 more	60 min
May 19, 3:33 PM CDT	Mesoscale Discussion	SPC	Armstrong, Borden, Briscoe, Carson, Castro, Childress and 27 more	117 min
May 19, 3:51 PM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Clay, Hardeman, Montague, Wichita and 1 more	114 min
May 19, 5:31 PM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Clay, Cooke, Foard, Hardeman and 6 more	89 min
May 19, 5:56 PM CDT	Tornado Watch	SPC	Comanche, Cooke, Denton, Eastland, Erath, Hood and 7 more	6 hr

Nearby

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.