Alert archive / Texas / Mesoscale Discussions in 2017

Mesoscale Discussion 177

February 13, 20176 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Feb 13, 2017, 8:24 PM CST for 6 counties in Texas. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued: Feb 13, 2017, 8:24 PM CST (02:24 UTC)
Expired: Feb 13, 2017, 10:00 PM CST
In force: 96 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Bandera County, TX, Kerr County, TX, Llano County, TX, Mason County, TX, McCulloch County, TX, San Saba County, TX

The radar

The Austin/San Antonio radar (KEWX), 115 km from the middle of the area, began a volume at 02:25 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, 2.4 hours before the alert went out and 180 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 596 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 184 m²/s²
0-3 km storm-relative helicity: 284 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.3

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
Feb 14, 3:57 AM CST	Mesoscale Discussion	SPC	Atascosa, Austin, Bee, Bexar, Brazoria, Colorado and 16 more	3 hr
Feb 14, 5:09 AM CST	Tornado Watch	SPC	Aransas, Austin, Bee, Brazoria, Calhoun, Chambers and 24 more	6 hr
Feb 14, 7:21 AM CST	Mesoscale Discussion	SPC	Brazoria, Calhoun, Chambers, Fort Bend, Galveston, Hardin and 12 more	114 min
Feb 14, 9:38 AM CST	Tornado Watch	SPC	Angelina, Hardin, Jasper, Jefferson, Nacogdoches, Newton and 5 more	5 hr
Feb 14, 11:15 AM CST	Mesoscale Discussion	SPC	Jasper, Newton, Orange, Sabine	90 min

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.