Alert archive / Texas / Mesoscale Discussions in 2009

Mesoscale Discussion 635

April 29, 200910 counties in Arkansas; Bossier Parish, Caddo Parish, Louisiana; 27 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 29, 2009, 5:19 PM CDT for 10 counties in Arkansas; Bossier Parish, Caddo Parish, Louisiana; 27 counties in Texas. It was in force for 116 min.

The area

The outline as issued.

The facts

Issued
Apr 29, 2009, 5:19 PM CDT (22:19 UTC)
Expired
Apr 29, 2009, 7:15 PM CDT
In force
116 min
Issued by
the Storm Prediction Center
All 39 counties

Clark County, AR, Columbia County, AR, Hempstead County, AR, Howard County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Nevada County, AR, Pike County, AR, Sevier County, AR, Bossier Parish, LA, Caddo Parish, LA, Bowie County, TX, Camp County, TX, Cass County, TX, Collin County, TX, Cooke County, TX, Delta County, TX, Denton County, TX, Franklin County, TX, Grayson County, TX, Gregg County, TX, Harrison County, TX, Hopkins County, TX, Hunt County, TX, Jack County, TX, Kaufman County, TX, Marion County, TX, Montague County, TX, Morris County, TX, Rains County, TX, Rockwall County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Van Zandt County, TX, Wise County, TX, Wood County, TX, Young County, TX

The radar

The Shreveport radar (KSHV), 172 km from the middle of the area, began a volume at 22:20 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

Fort Worth, TX (KFWD), launched 12:00Z, 10.3 hours before the alert went out and 178 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-pSkew-T log-p diagram, Fort Worth, TX at 12:00Z on 2009-04-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1229 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Fort Worth, TX at 12:00Z on 2009-04-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 130 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
1229 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
462 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
130 m²/s²
0-3 km storm-relative helicity
173 m²/s²
Significant tornado parameter
0.6
Supercell composite
3.4

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.

IssuedProductOfficeCountiesLasted
Apr 29, 9:36 AM CDTSevere Thunderstorm WatchSPCColumbia, Hempstead, Howard, Lafayette, Little River, Logan and 9 more6 hr
Apr 29, 12:58 PM CDTMesoscale DiscussionSPCHempstead, Howard, Lafayette, Little River, Miller, Montgomery and 5 more2 hr
Apr 29, 3:04 PM CDTMesoscale DiscussionSPCCalhoun, Clark, Columbia, Dallas, Grant, Hempstead and 10 more56 min
Apr 29, 3:27 PM CDTSevere Thunderstorm WatchSPCCalhoun, Clark, Columbia, Dallas, Garland, Grant and 13 more6 hr
Apr 29, 5:53 PM CDTMesoscale DiscussionSPCClark, Columbia, Hempstead, Lafayette, Little River, Miller and 2 more67 min
Apr 28, 7:23 PM CDTMesoscale DiscussionSPCAndrews, Armstrong, Bailey, Borden, Briscoe, Callahan and 61 more3 hr
Apr 28, 7:46 PM CDTMesoscale DiscussionSPCLoving, Pecos, Reeves, Ward, Winkler119 min
Apr 28, 9:25 PM CDTSevere Thunderstorm WatchSPCArmstrong, Bailey, Briscoe, Carson, Castro, Childress and 43 more6 hr
Apr 28, 10:33 PM CDTMesoscale DiscussionSPCAndrews, Armstrong, Bailey, Briscoe, Carson, Castro and 48 more87 min
Apr 28, 10:57 PM CDTSevere Thunderstorm WatchSPCAndrews, Dawson, Ector, Gaines, Loving, Martin and 2 more5 hr
Apr 29, 2:46 AM CDTMesoscale DiscussionSPCArmstrong, Bailey, Briscoe, Carson, Castro, Childress and 27 more89 min
Apr 29, 3:49 AM CDTSevere Thunderstorm WatchSPCArcher, Armstrong, Baylor, Briscoe, Carson, Childress and 19 more7 hr
Apr 29, 6:09 AM CDTMesoscale DiscussionSPCArcher, Baylor, Childress, Clay, Collingsworth, Cottle and 6 more96 min
Apr 29, 9:16 AM CDTMesoscale DiscussionSPCArcher, Baylor, Bowie, Camp, Cass, Clay and 26 more89 min
Apr 29, 12:07 PM CDTMesoscale DiscussionSPCBorden, Bosque, Callahan, Coke, Coleman, Comanche and 33 more113 min
Apr 29, 12:36 PM CDTTornado WatchSPCArcher, Baylor, Borden, Callahan, Clay, Crosby and 32 more9 hr
Apr 29, 2:03 PM CDTMesoscale DiscussionSPCCoke, Crockett, Glasscock, Irion, Midland, Reagan and 3 more57 min
Apr 29, 2:33 PM CDTTornado WatchSPCCoke, Concho, Crockett, Edwards, Glasscock, Irion and 14 more9 hr
Apr 29, 2:59 PM CDTMesoscale DiscussionSPCArmstrong, Briscoe, Carson, Donley, Floyd, Gray and 7 more91 min
Apr 29, 3:34 PM CDTMesoscale DiscussionSPCArcher, Baylor, Borden, Callahan, Clay, Crosby and 31 more56 min
Apr 29, 3:47 PM CDTTornado WatchSPCArmstrong, Briscoe, Carson, Childress, Collingsworth, Cottle and 18 more7 hr
Apr 29, 5:17 PM CDTMesoscale DiscussionSPCArmstrong, Briscoe, Carson, Childress, Collingsworth, Cottle and 18 more88 min
Apr 29, 6:21 PM CDTMesoscale DiscussionSPCArcher, Baylor, Borden, Callahan, Clay, Crosby and 33 more54 min

Nearby

Mesoscale Discussions in Texas, 2009Mesoscale Discussions in Arkansas, 2009Mesoscale Discussions in Louisiana, 2009Every 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.