Alert archive / Arkansas / Mesoscale Discussions in 2004

Mesoscale Discussion 419

April 21, 20044 states

The Storm Prediction Center issued this mesoscale discussion at Apr 21, 2004, 7:01 PM CDT for 4 states. It was in force for 119 min.

The area

The outline as issued.

The facts

Issued
Apr 21, 2004, 7:01 PM CDT (00:01 UTC)
Expired
Apr 21, 2004, 9:00 PM CDT
In force
119 min
Issued by
the Storm Prediction Center
All 31 counties

Clay County, AR, Craighead County, AR, Crittenden County, AR, Cross County, AR, Greene County, AR, Lawrence County, AR, Lee County, AR, Mississippi County, AR, Phillips County, AR, Poinsett County, AR, Randolph County, AR, St. Francis County, AR, Dunklin County, MO, Pemiscot County, MO, Benton County, MS, Coahoma County, MS, DeSoto County, MS, Lafayette County, MS, Marshall County, MS, Panola County, MS, Quitman County, MS, Tate County, MS, Tunica County, MS, Crockett County, TN, Dyer County, TN, Fayette County, TN, Haywood County, TN, Lake County, TN, Lauderdale County, TN, Shelby County, TN, Tipton County, TN

The nearest sounding before it

Little Rock, AR (KLZK), launched 00:00Z, 0.0 hours before the alert went out and 36 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, Little Rock, AR at 00:00Z on 2004-04-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 898 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, Little Rock, AR at 00:00Z on 2004-04-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 170 square meters per square second.19395878Sfc1 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
898 J/kg
Mixed-layer CIN
-28 J/kg
Mixed-layer LCL
600 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
170 m²/s²
0-3 km storm-relative helicity
295 m²/s²
Significant tornado parameter
1.2
Supercell composite
7.7

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
Apr 21, 8:12 PM CDTMesoscale DiscussionSPCArkansas, Ashley, Baxter, Benton, Boone, Bradley and 52 more63 min
Apr 21, 10:10 PM CDTMesoscale DiscussionSPCBenton, Washington95 min
Apr 21, 10:50 PM CDTSevere Thunderstorm WatchSPCCrawford, Sebastian5 hr
Apr 22, 1:43 AM CDTMesoscale DiscussionSPCCrawford, Logan, Sebastian92 min
Apr 22, 12:32 PM CDTMesoscale DiscussionSPCBenton, Washington88 min
Apr 22, 1:40 PM CDTTornado WatchSPCBenton, Boone, Carroll, Crawford, Franklin, Howard and 12 more6 hr
Apr 22, 3:26 PM CDTMesoscale DiscussionSPCCrawford, Franklin, Johnson, Logan, Madison, Newton and 6 more64 min
Apr 22, 5:27 PM CDTMesoscale DiscussionSPCBenton, Boone, Carroll, Crawford, Franklin, Howard and 12 more63 min
Apr 22, 6:23 PM CDTMesoscale DiscussionSPCBoone, Carroll, Crawford, Franklin, Howard, Johnson and 11 more67 min
Apr 22, 9:33 AM CDTMesoscale DiscussionSPCBenton, DeSoto, Marshall, Tippah117 min
Apr 22, 2:36 PM CDTMesoscale DiscussionSPCCalhoun, Carroll, Chickasaw, Clay, Grenada, Itawamba and 14 more114 min
Apr 22, 12:49 PM CDTMesoscale DiscussionSPCBedford, Campbell, Cannon, Cheatham, Clay, Coffee and 34 more2 hr

Nearby

Mesoscale Discussions in Arkansas, 2004Mesoscale Discussions in Mississippi, 2004Mesoscale Discussions in Tennessee, 2004Every mesoscale discussion in 2004

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.