Alert archive / Texas / Mesoscale Discussions in 2020

Mesoscale Discussion 339

April 11, 20206 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 11, 2020, 7:51 PM CDT for 6 counties in Texas. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued: Apr 11, 2020, 7:51 PM CDT (00:51 UTC)
Expired: Apr 11, 2020, 9:15 PM CDT
In force: 84 min
Issued by: the Storm Prediction Center
Chance of a watch: 40%

Counties Edwards County, TX, Kinney County, TX, Real County, TX, Sutton County, TX, Uvalde County, TX, Val Verde County, TX

The radar

The Laughlin AFB radar (KDFX), 78 km from the middle of the area, began a volume at 00:53 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 102Apr 11, 8:40 PM CDT

The nearest sounding before it

Del Rio, TX (KDRT), launched 00:00Z, 0.9 hours before the alert went out and 56 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: 3028 J/kg
Mixed-layer CIN: -37 J/kg
Mixed-layer LCL: 1174 m above ground
0-6 km bulk shear: 80 kt
0-1 km storm-relative helicity: 185 m²/s²
0-3 km storm-relative helicity: 286 m²/s²
Significant tornado parameter: 4.8
Supercell composite: 23.5

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
Apr 11, 8:37 PM CDT	Tornado Watch	SPC	Atascosa, Bandera, Bastrop, Bexar, Blanco, Caldwell and 23 more	5 hr
Apr 11, 9:23 PM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Callahan, Clay, Coke, Coleman and 23 more	67 min
Apr 11, 11:03 PM CDT	Mesoscale Discussion	SPC	Atascosa, Bandera, Bexar, Caldwell, Comal, DeWitt and 12 more	57 min
Apr 12, 1:37 AM CDT	Mesoscale Discussion	SPC	Bandera, Bell, Blanco, Bosque, Brazos, Brown and 44 more	113 min
Apr 12, 1:59 AM CDT	Tornado Watch	SPC	Bandera, Bastrop, Bell, Bexar, Blanco, Bosque and 37 more	6 hr
Apr 12, 4:15 AM CDT	Mesoscale Discussion	SPC	Bandera, Bastrop, Bell, Blanco, Bosque, Brown and 24 more	90 min
Apr 12, 5:52 AM CDT	Tornado Watch	SPC	Anderson, Angelina, Brazos, Burleson, Cherokee, Freestone and 19 more	8 hr
Apr 12, 7:18 AM CDT	Mesoscale Discussion	SPC	Anderson, Camp, Cass, Cherokee, Falls, Freestone and 20 more	87 min
Apr 12, 9:30 AM CDT	Mesoscale Discussion	SPC	San Augustine, Shelby	90 min
Apr 12, 1:10 PM CDT	Mesoscale Discussion	SPC	Camp, Collin, Cooke, Dallas, Delta, Denton and 17 more	95 min
Apr 12, 2:51 PM CDT	Severe Thunderstorm Watch	SPC	Bowie, Camp, Cass, Delta, Fannin, Franklin and 11 more	5 hr
Apr 12, 6:14 PM CDT	Mesoscale Discussion	SPC	Bowie, Camp, Cass, Franklin, Gregg, Harrison and 8 more	91 min

Nearby

Mesoscale Discussions in Texas, 2020 Every mesoscale discussion in 2020

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.