Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 589

April 26, 20114 states

The Storm Prediction Center issued this mesoscale discussion at Apr 26, 2011, 1:11 PM CDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 26, 2011, 1:11 PM CDT (18:11 UTC)
Expired
Apr 26, 2011, 3:15 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 81 counties

Bradley County, AR, Calhoun County, AR, Clark County, AR, Cleveland County, AR, Columbia County, AR, Dallas County, AR, Hempstead County, AR, Hot Spring County, AR, Howard County, AR, Lafayette County, AR, Lincoln 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, Claiborne Parish, LA, De Soto Parish, LA, Jackson Parish, LA, Lincoln Parish, LA, Red River Parish, LA, Sabine Parish, LA, Union Parish, LA, Webster Parish, LA, Bryan County, OK, Choctaw County, OK, McCurtain County, OK, Anderson County, TX, Angelina County, TX, Bosque County, TX, Bowie County, TX, Brazos County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Collin County, TX, Dallas County, TX, Delta County, TX, Ellis County, TX, Falls County, TX, Fannin County, TX, Franklin County, TX, Freestone County, TX, Gregg County, TX, Harrison County, TX, Henderson County, TX, Hill County, TX, Hopkins County, TX, Houston County, TX, Hunt County, TX, Johnson County, TX, Kaufman County, TX, Lamar County, TX, Leon County, TX, Limestone County, TX, Madison County, TX, Marion County, TX, McLennan County, TX, Morris County, TX, Nacogdoches County, TX, Navarro County, TX, Panola County, TX, Rains County, TX, Red River County, TX, Robertson County, TX, Rockwall County, TX, Rusk County, TX, San Augustine County, TX, Shelby County, TX, Smith County, TX, Tarrant County, TX, Titus County, TX, Trinity County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 116 km from the middle of the area, began a volume at 18:11 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, 6.2 hours before the alert went out and 123 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 2011-04-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1650 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 2011-04-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 148 square meters per square second.1939587897Sfc1 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
1650 J/kg
Mixed-layer CIN
-50 J/kg
Mixed-layer LCL
566 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
148 m²/s²
0-3 km storm-relative helicity
57 m²/s²
Significant tornado parameter
1.5
Supercell composite
7.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 25, 7:34 PM CDTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 33 more116 min
Apr 25, 9:23 PM CDTTornado WatchSPCAshley, Chicot7 hr
Apr 25, 11:05 PM CDTMesoscale DiscussionSPCAshley, Chicot115 min
Apr 26, 10:51 AM CDTMesoscale DiscussionSPCCrittenden, Cross, Lee, Mississippi, Phillips, Poinsett and 2 more54 min
Apr 26, 1:44 PM CDTTornado Watch PDSSPCBradley, Calhoun, Clark, Cleveland, Columbia, Dallas and 16 more10 hr
Apr 26, 2:41 PM CDTMesoscale DiscussionSPCArkansas, Chicot, Craighead, Crittenden, Cross, Desha and 11 more94 min
Apr 26, 3:02 PM CDTTornado Watch PDSSPCArkansas, Ashley, Chicot, Clay, Craighead, Crittenden and 21 more7 hr
Apr 26, 3:59 PM CDTMesoscale DiscussionSPCBradley, Calhoun, Clark, Cleveland, Columbia, Dallas and 12 more91 min
Apr 26, 5:00 PM CDTMesoscale DiscussionSPCBaxter, Boone, Cleburne, Conway, Crawford, Faulkner and 19 more30 min
Apr 26, 5:08 PM CDTTornado WatchSPCBaxter, Cleburne, Conway, Crawford, Franklin, Fulton and 15 more5 hr
Apr 26, 6:17 PM CDTMesoscale DiscussionSPCArkansas, Baxter, Benton, Boone, Bradley, Calhoun and 63 more118 min
Apr 26, 6:43 PM CDTMesoscale DiscussionSPCColumbia, Lafayette, Little River, Miller, Union2 hr
Apr 25, 9:37 PM CDTMesoscale DiscussionSPCDe Soto, Sabine83 min
Apr 25, 10:47 PM CDTTornado WatchSPCAllen, Beauregard, Evangeline, Rapides, Sabine, Vernon5 hr
Apr 26, 1:34 AM CDTMesoscale DiscussionSPCAllen, Beauregard, Calcasieu, Evangeline, Jefferson Davis, Rapides and 1 more86 min
Apr 26, 1:52 AM CDTSevere Thunderstorm WatchSPCAcadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 7 more5 hr
Apr 26, 4:56 PM CDTTornado WatchSPCBeauregard, Bienville, Caldwell, De Soto, Grant, Jackson and 9 more5 hr
Apr 26, 3:15 PM CDTMesoscale DiscussionSPCBeckham, Caddo, Canadian, Cleveland, Comanche, Cotton and 15 more90 min
Apr 26, 3:43 PM CDTSevere Thunderstorm WatchSPCAtoka, Beckham, Bryan, Caddo, Carter, Coal and 20 more6 hr
Apr 26, 3:01 PM CDTMesoscale DiscussionSPCAtascosa, Austin, Bastrop, Bee, Bexar, Blanco and 22 more89 min

Nearby

Mesoscale Discussions in Texas, 2011Mesoscale Discussions in Arkansas, 2011Mesoscale Discussions in Louisiana, 2011Every mesoscale discussion in 2011

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.