Alert archive / Texas / Mesoscale Discussions in 2009

Mesoscale Discussion 2160

October 29, 20099 counties in Arkansas; 19 parishes in Louisiana; 29 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Oct 29, 2009, 5:24 PM CDT for 9 counties in Arkansas; 19 parishes in Louisiana; 29 counties in Texas. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued: Oct 29, 2009, 5:24 PM CDT (22:24 UTC)
Expired: Oct 29, 2009, 6:30 PM CDT
In force: 66 min
Issued by: the Storm Prediction Center

All 57 counties

Columbia County, AR, Hempstead County, AR, Howard County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Nevada County, AR, Sevier County, AR, Union County, AR, Beauregard Parish, LA, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Sabine Parish, LA, Union Parish, LA, Vernon Parish, LA, Webster Parish, LA, Winn Parish, LA, Angelina County, TX, Bowie County, TX, Brazos County, TX, Burleson County, TX, Cass County, TX, Grimes County, TX, Hardin County, TX, Harris County, TX, Harrison County, TX, Houston County, TX, Jasper County, TX, Liberty County, TX, Madison County, TX, Marion County, TX, Montgomery County, TX, Nacogdoches County, TX, Newton County, TX, Panola County, TX, Polk County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, San Jacinto County, TX, Shelby County, TX, Trinity County, TX, Tyler County, TX, Walker County, TX, Waller County, TX, Washington County, TX

The radar

The Shreveport radar (KSHV), 94 km from the middle of the area, began a volume at 22:25 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

Shreveport, LA (KSHV), launched 12:00Z, 10.4 hours before the alert went out and 100 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: 387 J/kg
Mixed-layer CIN: -88 J/kg
Mixed-layer LCL: 453 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 350 m²/s²
0-3 km storm-relative helicity: 422 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.7

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
Oct 29, 1:14 PM CDT	Tornado Watch	SPC	Columbia, Hempstead, Howard, Lafayette, Little River, Miller and 3 more	8 hr
Oct 29, 1:51 PM CDT	Tornado Watch	SPC	Bradley, Calhoun, Clark, Cleveland, Dallas, Garland and 13 more	7 hr
Oct 29, 1:57 PM CDT	Mesoscale Discussion	SPC	Washington	2 hr
Oct 29, 3:03 PM CDT	Mesoscale Discussion	SPC	Bradley, Calhoun, Clark, Cleveland, Columbia, Dallas and 23 more	117 min
Oct 29, 5:27 PM CDT	Tornado Watch	SPC	Baxter, Boone, Carroll, Cleburne, Conway, Crawford and 22 more	3 hr
Oct 29, 10:48 AM CDT	Mesoscale Discussion	SPC	Allen, Beauregard, Bienville, Bossier, Caddo, De Soto and 7 more	117 min
Oct 28, 7:12 PM CDT	Mesoscale Discussion	SPC	Armstrong, Briscoe, Carson, Childress, Collingsworth, Cottle and 11 more	93 min
Oct 29, 1:07 AM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Bosque, Callahan, Clay, Collin and 25 more	53 min
Oct 29, 1:19 AM CDT	Tornado Watch	SPC	Collin, Cooke, Dallas, Delta, Denton, Ellis and 18 more	6 hr
Oct 29, 1:59 AM CDT	Tornado Watch	SPC	Archer, Baylor, Callahan, Clay, Eastland, Erath and 17 more	5 hr
Oct 29, 3:40 AM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Callahan, Clay, Collin, Cooke and 29 more	95 min
Oct 29, 5:19 AM CDT	Mesoscale Discussion	SPC	Austin, Brazos, Burleson, Chambers, Fort Bend, Grimes and 13 more	86 min
Oct 29, 5:31 AM CDT	Mesoscale Discussion	SPC	Collin, Cooke, Dallas, Denton, Fannin, Grayson and 7 more	89 min
Oct 29, 11:51 AM CDT	Tornado Watch	SPC	Anderson, Bell, Camp, Cherokee, Collin, Dallas and 30 more	6 hr
Oct 29, 5:03 PM CDT	Mesoscale Discussion	SPC	Anderson, Camp, Cherokee, Delta, Franklin, Freestone and 16 more	57 min

Nearby

Mesoscale Discussions in Texas, 2009 Mesoscale Discussions in Louisiana, 2009 Mesoscale Discussions in Arkansas, 2009 Every mesoscale discussion in 2009

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.