Alert archive / Texas / Mesoscale Discussions in 2007

Mesoscale Discussion 620

April 29, 200717 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 29, 2007, 7:25 PM CDT for 17 counties in Texas. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued: Apr 29, 2007, 7:25 PM CDT (00:25 UTC)
Expired: Apr 29, 2007, 8:30 PM CDT
In force: 65 min
Issued by: the Storm Prediction Center

Counties Brewster County, TX, Crane County, TX, Crockett County, TX, Culberson County, TX, Jeff Davis County, TX, Loving County, TX, Pecos County, TX, Presidio County, TX, Reagan County, TX, Reeves County, TX, Schleicher County, TX, Sutton County, TX, Terrell County, TX, Upton County, TX, Val Verde County, TX, Ward County, TX, Winkler County, TX

The radar

The Midland/Odessa radar (KMAF), 196 km from the middle of the area, began a volume at 00:27 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 200Apr 29, 7:45 PM CDT

The nearest sounding before it

Del Rio, TX (KDRT), launched 00:00Z, 0.4 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: 1523 J/kg
Mixed-layer CIN: -11 J/kg
Mixed-layer LCL: 1447 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 57 m²/s²
0-3 km storm-relative helicity: 182 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 6.7

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
Apr 29, 7:48 PM CDT	Tornado Watch	SPC	Bandera, Brewster, Crane, Crockett, Dimmit, Edwards and 18 more	7 hr
Apr 29, 8:35 PM CDT	Mesoscale Discussion	SPC	Baylor, Callahan, Coke, Coleman, Concho, Ector and 24 more	115 min
Apr 29, 10:42 PM CDT	Mesoscale Discussion	SPC	Bandera, Brewster, Crane, Crockett, Dimmit, Edwards and 18 more	63 min
Apr 30, 2:10 AM CDT	Mesoscale Discussion	SPC	Bandera, Crockett, Dimmit, Edwards, Frio, Kerr and 12 more	95 min
Apr 30, 2:47 AM CDT	Mesoscale Discussion	SPC	Bandera, Blanco, Burnet, Edwards, Gillespie, Kendall and 10 more	3 hr
Apr 30, 2:51 AM CDT	Severe Thunderstorm Watch	SPC	Bandera, Blanco, Burnet, Edwards, Gillespie, Kendall and 9 more	5 hr
Apr 30, 4:46 AM CDT	Mesoscale Discussion	SPC	Bandera, Blanco, Burnet, Edwards, Gillespie, Kendall and 9 more	119 min
Apr 30, 12:37 PM CDT	Mesoscale Discussion	SPC	Atascosa, Bastrop, Bee, Caldwell, DeWitt, Dimmit and 15 more	83 min
Apr 30, 1:22 PM CDT	Mesoscale Discussion	SPC	Camp, Collin, Dallas, Delta, Fannin, Franklin and 14 more	113 min
Apr 30, 1:26 PM CDT	Severe Thunderstorm Watch	SPC	Austin, Brazoria, Colorado, DeWitt, Fayette, Fort Bend and 10 more	7 hr
Apr 30, 3:01 PM CDT	Tornado Watch	SPC	Dimmit, Duval, Frio, Jim Wells, La Salle, Live Oak and 4 more	7 hr
Apr 30, 3:23 PM CDT	Mesoscale Discussion	SPC	Grimes, Harris, Houston, Leon, Liberty, Madison and 4 more	97 min
Apr 30, 5:38 PM CDT	Mesoscale Discussion	SPC	Archer, Armstrong, Baylor, Borden, Briscoe, Callahan and 42 more	2 hr
Apr 30, 6:18 PM CDT	Mesoscale Discussion	SPC	Dimmit, Duval, Frio, Jim Wells, La Salle, Live Oak and 4 more	57 min
Apr 30, 6:37 PM CDT	Mesoscale Discussion	SPC	Austin, Brazoria, Colorado, DeWitt, Fayette, Fort Bend and 10 more	83 min

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.