Alert archive / Texas / Mesoscale Discussions in 2007

Mesoscale Discussion 280

March 13, 200718 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Mar 13, 2007, 6:20 PM CDT for 18 counties in Texas. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued: Mar 13, 2007, 6:20 PM CDT (23:20 UTC)
Expired: Mar 13, 2007, 7:15 PM CDT
In force: 55 min
Issued by: the Storm Prediction Center

Counties Atascosa County, TX, Bee County, TX, Calhoun County, TX, DeWitt County, TX, Frio County, TX, Goliad County, TX, Jackson County, TX, Karnes County, TX, La Salle County, TX, Lavaca County, TX, Live Oak County, TX, Matagorda County, TX, McMullen County, TX, Refugio County, TX, San Patricio County, TX, Victoria County, TX, Wharton County, TX, Wilson County, TX

The radar

The Corpus Christi radar (KCRP), 115 km from the middle of the area, began a volume at 23:23 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 61Mar 13, 6:40 PM CDT

The nearest sounding before it

Corpus Christi, TX (KCRP), launched 12:00Z, 11.3 hours before the alert went out and 120 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: 418 J/kg
Mixed-layer CIN: -134 J/kg
Mixed-layer LCL: 595 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 101 m²/s²
0-3 km storm-relative helicity: 111 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.5

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
Mar 12, 7:39 PM CDT	Mesoscale Discussion	SPC	Atascosa, Bastrop, Bexar, Blanco, Burleson, Caldwell and 19 more	3 hr
Mar 13, 11:03 AM CDT	Mesoscale Discussion	SPC	Atascosa, Bandera, Bastrop, Bee, Bell, Bexar and 45 more	117 min
Mar 13, 12:58 PM CDT	Severe Thunderstorm Watch	SPC	Atascosa, Bandera, Bastrop, Bell, Bexar, Blanco and 61 more	6 hr
Mar 13, 2:38 PM CDT	Mesoscale Discussion	SPC	Cooke, Grayson, Lamar, Montague	97 min
Mar 13, 3:35 PM CDT	Mesoscale Discussion	SPC	Atascosa, Bandera, Bastrop, Bell, Bexar, Blanco and 71 more	85 min
Mar 13, 6:40 PM CDT	Tornado Watch	SPC	Aransas, Austin, Bee, Brazoria, Calhoun, Chambers and 25 more	7 hr

Nearby

Mesoscale Discussions in Texas, 2007 Every mesoscale discussion in 2007

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.