Alert archive / Texas / Mesoscale Discussions in 2017

Mesoscale Discussion 197

February 20, 20177 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Feb 20, 2017, 4:32 AM CST for 7 counties in Texas. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Feb 20, 2017, 4:32 AM CST (10:32 UTC)
Expired: Feb 20, 2017, 7:30 AM CST
In force: 3 hr
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Aransas County, TX, Calhoun County, TX, Cameron County, TX, Kenedy County, TX, Kleberg County, TX, Nueces County, TX, Willacy County, TX

The radar

The Corpus Christi radar (KCRP), 65 km from the middle of the area, began a volume at 10:34 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

Corpus Christi, TX (KCRP), launched 00:00Z, 10.5 hours before the alert went out and 54 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: 1800 J/kg
Mixed-layer CIN: -144 J/kg
Mixed-layer LCL: 663 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 178 m²/s²
0-3 km storm-relative helicity: 139 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 9.8

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 19, 6:18 PM CST	Severe Thunderstorm Watch	SPC	Atascosa, Bandera, Bastrop, Bexar, Caldwell, Comal and 20 more	8 hr
Feb 19, 6:43 PM CST	Mesoscale Discussion	SPC	Archer, Baylor, Brown, Callahan, Clay, Coleman and 26 more	2 hr
Feb 19, 8:13 PM CST	Mesoscale Discussion	SPC	Bandera, Dimmit, Edwards, Kerr, Kinney, Maverick and 3 more	2 hr
Feb 19, 8:33 PM CST	Mesoscale Discussion	SPC	Bosque, Comanche, Cooke, Coryell, Denton, Erath and 15 more	117 min
Feb 19, 8:36 PM CST	Severe Thunderstorm Watch	SPC	Brooks, Duval, Jim Hogg, Jim Wells, La Salle, Live Oak and 4 more	4 hr
Feb 19, 10:28 PM CST	Mesoscale Discussion	SPC	Atascosa, Bexar, Comal, Kendall, McMullen, Wilson	92 min
Feb 19, 11:50 PM CST	Mesoscale Discussion	SPC	Bastrop, Brazos, Burleson, Falls, Fayette, Grimes and 4 more	85 min
Feb 20, 1:56 AM CST	Mesoscale Discussion	SPC	Brazos, Houston, Leon, Madison, Trinity, Walker	3 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.