Alert archive / Texas / Mesoscale Discussions in 2009

Mesoscale Discussion 672

May 2, 200911 counties in Arkansas; 18 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 2, 2009, 3:47 PM CDT for 11 counties in Arkansas; 18 counties in Texas. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued
May 2, 2009, 3:47 PM CDT (20:47 UTC)
Expired
May 2, 2009, 4:45 PM CDT
In force
58 min
Issued by
the Storm Prediction Center
All 29 counties

Ashley County, AR, Bradley County, AR, Calhoun County, AR, Columbia County, AR, Drew County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Nevada County, AR, Ouachita County, AR, Union County, AR, Bowie County, TX, Camp County, TX, Cass County, TX, Dallas County, TX, Delta County, TX, Franklin County, TX, Hopkins County, TX, Hunt County, TX, Kaufman County, TX, Lamar County, TX, Morris County, TX, Rains County, TX, Red River County, TX, Rockwall County, TX, Titus County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 102 km from the middle of the area, began a volume at 20:48 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.

The nearest sounding before it

Shreveport, LA (KSHV), launched 12:00Z, 8.8 hours before the alert went out and 104 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, Shreveport, LA at 12:00Z on 2009-05-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1211 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, Shreveport, LA at 12:00Z on 2009-05-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 134 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
1211 J/kg
Mixed-layer CIN
-39 J/kg
Mixed-layer LCL
501 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
134 m²/s²
0-3 km storm-relative helicity
172 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.4

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
May 1, 9:36 PM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Cleburne, Conway and 34 more84 min
May 1, 9:56 PM CDTSevere Thunderstorm WatchSPCArkansas, Clark, Cleburne, Conway, Crawford, Faulkner and 27 more6 hr
May 2, 1:45 AM CDTMesoscale DiscussionSPCArkansas, Clark, Cleburne, Cleveland, Conway, Crittenden and 34 more90 min
May 2, 9:23 AM CDTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 26 more97 min
May 2, 12:17 PM CDTTornado WatchSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 19 more7 hr
May 2, 5:25 PM CDTMesoscale DiscussionSPCAshley, Bradley, Calhoun, Columbia, Drew, Lafayette and 4 more95 min
May 2, 6:03 PM CDTTornado WatchSPCAshley, Bradley, Calhoun, Chicot, Columbia, Desha and 10 more6 hr
May 1, 7:19 PM CDTMesoscale DiscussionSPCArcher, Baylor, Childress, Clay, Cooke, Cottle and 21 more86 min
May 2, 2:58 AM CDTMesoscale DiscussionSPCCollingsworth, Gray, Hemphill, Wheeler3 hr
May 2, 1:24 PM CDTMesoscale DiscussionSPCBell, Blanco, Bosque, Burnet, Collin, Coryell and 31 more66 min
May 2, 1:56 PM CDTTornado WatchSPCBell, Bosque, Coryell, Dallas, Ellis, Falls and 18 more4 hr
May 2, 3:04 PM CDTMesoscale DiscussionSPCAnderson, Camp, Cherokee, Gregg, Harrison, Houston and 10 more26 min
May 2, 5:10 PM CDTMesoscale DiscussionSPCHarrison, Panola, Rusk65 min
May 2, 6:49 PM CDTMesoscale DiscussionSPCCamp, Cass, Franklin, Hopkins, Hunt, Kaufman and 7 more86 min

Nearby

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