Alert archive / Missouri / Mesoscale Discussions in 2004

Mesoscale Discussion 402

April 20, 2004Calhoun County, Illinois; 22 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Apr 20, 2004, 9:38 PM CDT for Calhoun County, Illinois; 22 counties in Missouri. It was in force for 37 min.

The area

The outline as issued.

The facts

Issued
Apr 20, 2004, 9:38 PM CDT (02:38 UTC)
Expired
Apr 20, 2004, 10:15 PM CDT
In force
37 min
Issued by
the Storm Prediction Center
All 23 counties

Calhoun County, IL, Audrain County, MO, Boone County, MO, Callaway County, MO, Cole County, MO, Crawford County, MO, Dent County, MO, Franklin County, MO, Gasconade County, MO, Jefferson County, MO, Lincoln County, MO, Maries County, MO, Miller County, MO, Moniteau County, MO, Montgomery County, MO, Osage County, MO, Phelps County, MO, Pike County, MO, Pulaski County, MO, Saint Charles County, MO, Saint Louis County, MO, Warren County, MO, Washington County, MO

The nearest sounding before it

Springfield, MO (KSGF), launched 00:00Z, 2.6 hours before the alert went out and 251 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, Springfield, MO at 00:00Z on 2004-04-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 40 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, Springfield, MO at 00:00Z on 2004-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 147 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
40 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
860 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
147 m²/s²
0-3 km storm-relative helicity
176 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

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 20, 8:55 PM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, Cook, DeKalb, DuPage and 13 more65 min
Apr 20, 11:10 PM CDTMesoscale DiscussionSPCBrown, Calhoun, Cass, Christian, Fulton, Greene and 15 more2 hr
Apr 21, 2:58 PM CDTMesoscale DiscussionSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Jackson and 13 more92 min
Apr 20, 7:20 PM CDTMesoscale DiscussionSPCAdair, Audrain, Bates, Benton, Boone, Caldwell and 38 more115 min
Apr 20, 7:22 PM CDTMesoscale DiscussionSPCBarry, Barton, Cedar, Dade, Jasper, Lawrence and 4 more23 min
Apr 20, 7:50 PM CDTTornado WatchSPCBarry, McDonald, Stone, Taney5 hr
Apr 20, 8:06 PM CDTMesoscale DiscussionSPCAtchison84 min
Apr 20, 8:57 PM CDTMesoscale DiscussionSPCBarry, McDonald, Stone, Taney2 hr
Apr 20, 10:57 PM CDTMesoscale DiscussionSPCBarry, McDonald, Stone, Taney93 min

Nearby

Mesoscale Discussions in Missouri, 2004Mesoscale Discussions in Illinois, 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.