Alert archive / Texas / Mesoscale Discussions in 2013

Mesoscale Discussion 756

May 21, 20134 states

The Storm Prediction Center issued this mesoscale discussion at May 21, 2013, 3:18 PM CDT for 4 states. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued
May 21, 2013, 3:18 PM CDT (20:18 UTC)
Expired
May 21, 2013, 4:45 PM CDT
In force
87 min
Issued by
the Storm Prediction Center
All 83 counties

Bradley County, AR, Calhoun County, AR, Clark County, AR, Cleveland County, AR, Columbia County, AR, Dallas County, AR, Grant County, AR, Hempstead County, AR, Howard County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Nevada County, AR, Ouachita County, AR, Pike County, AR, Sevier County, AR, Union County, AR, 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, Webster Parish, LA, Winn Parish, LA, Bryan County, OK, Choctaw County, OK, McCurtain County, OK, Pushmataha County, OK, Anderson County, TX, Bosque County, TX, Bowie County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Collin County, TX, Coryell County, TX, Dallas County, TX, Delta County, TX, Ellis County, TX, Fannin County, TX, Franklin County, TX, Freestone County, TX, Gregg County, TX, Hamilton County, TX, Harrison County, TX, Henderson County, TX, Hill County, TX, Hopkins County, TX, Hunt County, TX, Kaufman County, TX, Kimble County, TX, Lamar County, TX, Lampasas County, TX, Limestone County, TX, Marion County, TX, Mason County, TX, McLennan County, TX, Menard County, TX, Morris County, TX, Nacogdoches County, TX, Navarro County, TX, Panola County, TX, Rains County, TX, Red River County, TX, Rockwall County, TX, Rusk County, TX, San Saba County, TX, Shelby County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 108 km from the middle of the area, began a volume at 20:22 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

Fort Worth, TX (KFWD), launched 12:00Z, 8.3 hours before the alert went out and 117 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 2013-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1513 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 2013-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 316 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
1513 J/kg
Mixed-layer CIN
-271 J/kg
Mixed-layer LCL
793 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
316 m²/s²
0-3 km storm-relative helicity
251 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.6

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 20, 7:39 PM CDTTornado WatchSPCBaxter, Benton, Boone, Carroll, Cleburne, Conway and 26 more6 hr
May 21, 12:03 AM CDTSevere Thunderstorm WatchSPCCrawford, Franklin, Sebastian7 hr
May 21, 12:50 AM CDTSevere Thunderstorm WatchSPCClay, Craighead, Crittenden, Cross, Greene, Lawrence and 5 more3 hr
May 21, 4:20 AM CDTMesoscale DiscussionSPCCrawford, Franklin, Sebastian55 min
May 21, 7:47 AM CDTMesoscale DiscussionSPCCrittenden, Cross, Lee, Mississippi, Phillips, Poinsett and 1 more58 min
May 21, 1:35 PM CDTMesoscale DiscussionSPCLafayette, Miller115 min
May 21, 1:50 PM CDTTornado WatchSPCBradley, Calhoun, Clark, Cleveland, Columbia, Dallas and 13 more8 hr
May 21, 2:42 PM CDTMesoscale DiscussionSPCClay, Craighead, Crittenden, Cross, Greene, Jackson and 8 more63 min
May 21, 3:00 PM CDTTornado WatchSPCArkansas, Ashley, Chicot, Clay, Craighead, Crittenden and 11 more7 hr
May 21, 5:54 PM CDTMesoscale DiscussionSPCCalhoun, Columbia, Hempstead, Lafayette, Miller, Nevada and 2 more66 min
May 21, 6:23 PM CDTMesoscale DiscussionSPCChicot, Desha67 min
May 20, 11:36 PM CDTMesoscale DiscussionSPCAtoka, Coal, Garvin, Hughes, Murray, Pittsburg and 2 more24 min
May 21, 8:12 AM CDTMesoscale DiscussionSPCAtoka, Bryan, Carter, Choctaw, Coal, Jefferson and 8 more93 min
May 21, 9:46 AM CDTMesoscale DiscussionSPCCaddo, Canadian, Cleveland, Comanche, Cotton, Creek and 26 more2 hr
May 21, 10:26 AM CDTTornado WatchSPCBryan, Choctaw, Love, Marshall10 hr
May 21, 10:45 AM CDTSevere Thunderstorm WatchSPCAtoka, Caddo, Canadian, Carter, Cleveland, Coal and 30 more6 hr
May 21, 1:19 PM CDTMesoscale DiscussionSPCBryan, Choctaw, Marshall, Pushmataha116 min
May 20, 8:45 PM CDTMesoscale DiscussionSPCBosque, Brown, Burnet, Callahan, Clay, Coleman and 37 more60 min
May 21, 10:09 AM CDTMesoscale DiscussionSPCAnderson, Bosque, Bowie, Brown, Callahan, Camp and 57 more96 min
May 21, 4:55 PM CDTMesoscale DiscussionSPCBrazos, Burleson, Houston, Madison, Trinity, Walker95 min
May 21, 6:55 PM CDTSevere Thunderstorm WatchSPCBrazos, Burleson, Grimes, Hardin, Houston, Jasper and 9 more6 hr

Nearby

Mesoscale Discussions in Texas, 2013Mesoscale Discussions in Arkansas, 2013Mesoscale Discussions in Louisiana, 2013Every mesoscale discussion in 2013

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.