Alert archive / Texas / Mesoscale Discussions in 2015

Mesoscale Discussion 631

May 13, 20158 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 13, 2015, 7:34 AM CDT for 8 counties in Texas. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued: May 13, 2015, 7:34 AM CDT (12:34 UTC)
Expired: May 13, 2015, 8:30 AM CDT
In force: 56 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Bandera County, TX, Dimmit County, TX, Frio County, TX, La Salle County, TX, Medina County, TX, Real County, TX, Uvalde County, TX, Zavala County, TX

The radar

The Laughlin AFB radar (KDFX), 86 km from the middle of the area, began a volume at 12:36 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 169May 13, 9:50 AM CDT

The nearest sounding before it

Del Rio, TX (KDLF), launched 12:00Z, 0.6 hours before the alert went out and 140 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: 428 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 532 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 255 m²/s²
0-3 km storm-relative helicity: 299 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.1

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 13, 9:52 AM CDT	Tornado Watch	SPC	Atascosa, Bastrop, Bee, Bexar, Blanco, Burnet and 27 more	8 hr
May 13, 11:43 AM CDT	Mesoscale Discussion	SPC	Bee, Duval, Live Oak	2 hr
May 13, 12:49 PM CDT	Mesoscale Discussion	SPC	Borden, Coke, Concho, Crockett, Dawson, Fisher and 19 more	2 hr
May 13, 2:24 PM CDT	Mesoscale Discussion	SPC	Anderson, Cherokee, Freestone, Grimes, Henderson, Houston and 8 more	3 hr
May 13, 3:09 PM CDT	Severe Thunderstorm Watch	SPC	Coke, Concho, Crockett, Dimmit, Edwards, Irion and 16 more	7 hr
May 13, 3:37 PM CDT	Mesoscale Discussion	SPC	Briscoe, Childress, Collingsworth, Cottle, Dickens, Donley and 9 more	2 hr
May 13, 6:46 PM CDT	Mesoscale Discussion	SPC	Coke, Coleman, Concho, Crockett, Edwards, Irion and 14 more	89 min

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.