Alert archive / Illinois / Mesoscale Discussions in 2004

Mesoscale Discussion 2322

October 18, 20044 states

The Storm Prediction Center issued this mesoscale discussion at Oct 18, 2004, 10:20 AM CDT for 4 states. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued
Oct 18, 2004, 10:20 AM CDT (15:20 UTC)
Expired
Oct 18, 2004, 11:45 AM CDT
In force
85 min
Issued by
the Storm Prediction Center
All 72 counties

Alexander County, IL, Bond County, IL, Clay County, IL, Clinton County, IL, Edwards County, IL, Effingham County, IL, Fayette County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Jefferson County, IL, Johnson County, IL, Lawrence County, IL, Madison County, IL, Marion County, IL, Massac County, IL, Monroe County, IL, Montgomery County, IL, Perry County, IL, Pope County, IL, Pulaski County, IL, Randolph County, IL, Richland County, IL, Saint Clair County, IL, Saline County, IL, Union County, IL, Wabash County, IL, Washington County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Gibson County, IN, Posey County, IN, Vanderburgh County, IN, Warrick County, IN, Ballard County, KY, Caldwell County, KY, Calloway County, KY, Carlisle County, KY, Crittenden County, KY, Daviess County, KY, Fulton County, KY, Graves County, KY, Henderson County, KY, Hickman County, KY, Hopkins County, KY, Livingston County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, McLean County, KY, Trigg County, KY, Union County, KY, Webster County, KY, Bollinger County, MO, Cape Girardeau County, MO, City of Saint Louis, MO, Iron County, MO, Jefferson County, MO, Madison County, MO, Mississippi County, MO, Perry County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Scott County, MO, Stoddard County, MO, Washington County, MO, Wayne County, MO

The radar

The Paducah radar (KPAH), 107 km from the middle of the area, began a volume at 15:22 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

Lincoln, IL (KILX), launched 12:00Z, 3.3 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, Lincoln, IL at 12:00Z on 2004-10-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Lincoln, IL at 12:00Z on 2004-10-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 161 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
480 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
161 m²/s²
0-3 km storm-relative helicity
217 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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
Oct 17, 10:01 PM CDTMesoscale DiscussionSPCMonroe, Randolph3 hr
Oct 17, 11:30 PM CDTSevere Thunderstorm WatchSPCMonroe, Randolph, Saint Clair6 hr
Oct 18, 2:19 AM CDTMesoscale DiscussionSPCAlexander, Monroe, Randolph, Saint Clair56 min
Oct 18, 4:40 AM CDTMesoscale DiscussionSPCAlexander, Bond, Calhoun, Clay, Clinton, Fayette and 16 more35 min
Oct 18, 7:44 AM CDTMesoscale DiscussionSPCAlexander, Massac, Pulaski61 min
Oct 18, 12:04 PM CDTMesoscale DiscussionSPCAlexander, Jackson, Monroe, Pulaski, Randolph, Union86 min
Oct 18, 12:40 PM CDTTornado WatchSPCAlexander, Clinton, Jackson, Monroe, Perry, Randolph and 2 more5 hr
Oct 18, 1:55 PM CDTMesoscale DiscussionSPCGallatin, Hardin, Johnson, Massac, Pope, Pulaski and 2 more95 min
Oct 18, 3:41 PM CDTMesoscale DiscussionSPCAlexander, Clinton, Jackson, Monroe, Perry, Randolph and 3 more94 min
Oct 18, 5:05 PM CDTTornado WatchSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 17 more5 hr
Oct 18, 6:05 PM CDTMesoscale DiscussionSPCBond, Clay, Clinton, Crawford, Edwards, Effingham and 23 more115 min
Oct 18, 4:05 PM CDTTornado WatchSPCDunklin, Pemiscot5 hr

Nearby

Mesoscale Discussions in Illinois, 2004Mesoscale Discussions in Kentucky, 2004Mesoscale Discussions in Missouri, 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; radar from the NEXRAD Level II archive.