Alert archive / Illinois / Mesoscale Discussions in 2003

Mesoscale Discussion 801

May 6, 200315 counties in Illinois; 6 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at May 6, 2003, 5:08 PM CDT for 15 counties in Illinois; 6 counties in Missouri. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 6, 2003, 5:08 PM CDT (22:08 UTC)
Expired
May 6, 2003, 7:15 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 21 counties

Bond County, IL, Calhoun County, IL, Clinton County, IL, Fayette County, IL, Jackson County, IL, Jefferson County, IL, Jersey County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Perry County, IL, Randolph County, IL, Saint Clair County, IL, Washington County, IL, City of Saint Louis, MO, Franklin County, MO, Jefferson County, MO, Saint Charles County, MO, Saint Louis County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 29 km from the middle of the area, began a volume at 22:11 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

Springfield, MO (KSGF), launched 12:00Z, 10.1 hours before the alert went out and 356 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 12:00Z on 2003-05-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 34 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 12:00Z on 2003-05-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 86 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
34 J/kg
Mixed-layer CIN
-216 J/kg
Mixed-layer LCL
1877 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
86 m²/s²
0-3 km storm-relative helicity
115 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

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
May 5, 10:58 PM CDTMesoscale DiscussionSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 9 more2 hr
May 6, 9:37 AM CDTMesoscale DiscussionSPCBond, Clark, Clay, Clinton, Crawford, Cumberland and 15 more113 min
May 6, 11:55 AM CDTSevere Thunderstorm WatchSPCBond, Clay, Clinton, Crawford, Edwards, Effingham and 21 more4 hr
May 6, 1:23 PM CDTMesoscale DiscussionSPCBond, Clay, Clinton, Crawford, Edwards, Effingham and 17 more2 hr
May 6, 5:33 PM CDTMesoscale DiscussionSPCBond, Calhoun, Clinton, Fayette, Jackson, Jefferson and 9 more117 min
May 6, 5:40 PM CDTTornado WatchSPCAlexander, Bond, Clay, Clinton, Crawford, Edwards and 28 more6 hr
May 6, 1:50 AM CDTTornado WatchSPCDunklin, Pemiscot6 hr
May 6, 6:49 AM CDTMesoscale DiscussionSPCBarton, Bates, Benton, Caldwell, Camden, Carroll and 27 more3 hr
May 6, 7:55 AM CDTSevere Thunderstorm WatchSPCBarton, Bates, Benton, Camden, Cass, Cedar and 22 more5 hr
May 6, 10:32 AM CDTMesoscale DiscussionSPCMcDonald118 min
May 6, 11:29 AM CDTMesoscale DiscussionSPCBarton, Bates, Benton, Cass, Cedar, Clay and 18 more2 hr
May 6, 11:40 AM CDTTornado WatchSPCBarry, Barton, Bates, Benton, Cass, Cedar and 20 more7 hr
May 6, 2:15 PM CDTTornado WatchSPCBoone, Callaway, Camden, Carter, Cole, Cooper and 27 more5 hr
May 6, 3:42 PM CDTMesoscale DiscussionSPCBarton, Bates, Benton, Boone, Callaway, Camden and 20 more2 hr
May 6, 6:35 PM CDTTornado WatchSPCBarry, Barton, Camden, Carter, Cedar, Christian and 31 more5 hr

Nearby

Mesoscale Discussions in Illinois, 2003Mesoscale Discussions in Missouri, 2003Every mesoscale discussion in 2003

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.