Alert archive / Texas / Mesoscale Discussions in 2008

Mesoscale Discussion 458

March 18, 20084 states

The Storm Prediction Center issued this mesoscale discussion at Mar 18, 2008, 9:26 AM CDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Mar 18, 2008, 9:26 AM CDT (14:26 UTC)
Expired
Mar 18, 2008, 11:30 AM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 62 counties

Calhoun County, AR, Clark County, AR, Columbia County, AR, Conway County, AR, Dallas County, AR, Garland County, AR, Grant County, AR, Hempstead County, AR, Hot Spring County, AR, Howard County, AR, Lafayette County, AR, Little River County, AR, Logan County, AR, Miller County, AR, Montgomery County, AR, Nevada County, AR, Ouachita County, AR, Perry County, AR, Pike County, AR, Polk County, AR, Pulaski County, AR, Saline County, AR, Scott County, AR, Sevier County, AR, Yell County, AR, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, Webster Parish, LA, Choctaw County, OK, McCurtain County, OK, Anderson County, TX, Bowie County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Delta County, TX, Ellis County, TX, Fannin County, TX, Franklin County, TX, Freestone County, TX, Gregg County, TX, Harrison County, TX, Henderson County, TX, Hopkins County, TX, Hunt County, TX, Kaufman County, TX, Lamar County, TX, Limestone County, TX, Marion County, TX, Morris County, TX, Navarro County, TX, Panola County, TX, Rains County, TX, Red River County, TX, Rockwall County, TX, Rusk County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 147 km from the middle of the area, began a volume at 14:29 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, 2.4 hours before the alert went out and 147 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 2008-03-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 682 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 2008-03-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 356 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
682 J/kg
Mixed-layer CIN
-38 J/kg
Mixed-layer LCL
741 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
356 m²/s²
0-3 km storm-relative helicity
487 m²/s²
Significant tornado parameter
1.7
Supercell composite
6.7

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
Mar 17, 7:34 PM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Crawford, Franklin and 11 more56 min
Mar 17, 9:36 PM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Cleburne, Conway and 20 more114 min
Mar 17, 10:16 PM CDTTornado WatchSPCBaxter, Benton, Boone, Carroll, Cleburne, Conway and 31 more8 hr
Mar 18, 1:13 AM CDTMesoscale DiscussionSPCWashington62 min
Mar 18, 2:23 AM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Fulton, Madison and 2 more2 hr
Mar 18, 2:46 AM CDTMesoscale DiscussionSPCBaxter, Cleburne, Conway, Crawford, Faulkner, Franklin and 27 more89 min
Mar 18, 5:54 AM CDTMesoscale DiscussionSPCBenton, Boone, Carroll, Crawford, Madison, Washington2 hr
Mar 18, 10:16 AM CDTTornado Watch PDSSPCArkansas, Clark, Clay, Cleburne, Cleveland, Columbia and 48 more7 hr
Mar 18, 10:59 AM CDTTornado Watch PDSSPCUnion8 hr
Mar 18, 11:54 AM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Crawford, Franklin and 6 more3 hr
Mar 18, 12:10 PM CDTMesoscale DiscussionSPCArkansas, Clark, Cleburne, Cleveland, Conway, Craighead and 47 more2 hr
Mar 18, 1:51 PM CDTMesoscale DiscussionSPCPolk, Sevier3 hr
Mar 18, 3:54 PM CDTMesoscale DiscussionSPCClark, Cleburne, Columbia, Dallas, Faulkner, Garland and 21 more2 hr
Mar 18, 4:46 PM CDTMesoscale DiscussionSPCArkansas, Clark, Clay, Craighead, Crittenden, Cross and 19 more59 min
Mar 18, 5:19 PM CDTTornado WatchSPCArkansas, Bradley, Calhoun, Clark, Clay, Cleburne and 43 more11 hr
Mar 18, 6:06 PM CDTMesoscale DiscussionSPCClark, Clay, Cleburne, Conway, Craighead, Cross and 20 more3 hr
Mar 18, 6:47 PM CDTTornado WatchSPCUnion9 hr
Mar 18, 6:19 PM CDTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Beauregard, Bienville, Bossier and 22 more56 min
Mar 17, 7:09 PM CDTSevere Thunderstorm WatchSPCCaddo, Canadian, Carter, Cleveland, Coal, Comanche and 19 more7 hr
Mar 17, 10:21 PM CDTMesoscale DiscussionSPCBlaine, Caddo, Canadian, Carter, Cleveland, Coal and 25 more54 min
Mar 17, 9:17 PM CDTMesoscale DiscussionSPCBandera, Blanco, Bosque, Brown, Burnet, Callahan and 53 more58 min
Mar 17, 11:06 PM CDTMesoscale DiscussionSPCBandera, Blanco, Bosque, Brown, Burnet, Callahan and 53 more54 min
Mar 18, 1:32 AM CDTMesoscale DiscussionSPCBrown, Callahan, Coke, Coleman, Concho, Crockett and 9 more58 min
Mar 18, 1:43 AM CDTMesoscale DiscussionSPCBrown, Callahan, Coke, Coleman, Concho, Crockett and 9 more32 min
Mar 18, 1:52 AM CDTTornado WatchSPCBandera, Blanco, Bosque, Brown, Burnet, Callahan and 34 more7 hr
Mar 18, 4:57 AM CDTMesoscale DiscussionSPCBandera, Blanco, Burnet, Coryell, Gillespie, Hamilton and 7 more93 min
Mar 18, 7:22 AM CDTMesoscale DiscussionSPCAnderson, Austin, Bastrop, Bell, Brazoria, Brazos and 40 more113 min
Mar 18, 7:50 AM CDTMesoscale DiscussionSPCBandera, Bosque, Brown, Burnet, Coleman, Comanche and 19 more55 min
Mar 18, 1:19 PM CDTMesoscale DiscussionSPCAnderson, Austin, Bastrop, Bell, Brazos, Burleson and 37 more116 min

Nearby

Mesoscale Discussions in Texas, 2008Mesoscale Discussions in Arkansas, 2008Mesoscale Discussions in Louisiana, 2008Every mesoscale discussion in 2008

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.