Alert archive / Illinois / Mesoscale Discussions in 2014

Mesoscale Discussion 638

May 21, 20144 states

The Storm Prediction Center issued this mesoscale discussion at May 21, 2014, 1:40 PM CDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 21, 2014, 1:40 PM CDT (18:40 UTC)
Expired
May 21, 2014, 3:45 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
60%
All 42 counties

Lee County, IA, Adams County, IL, Brown County, IL, Cass County, IL, Champaign County, IL, Christian County, IL, Clark County, IL, Coles County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Ford County, IL, Fulton County, IL, Hancock County, IL, Henderson County, IL, Logan County, IL, Macon County, IL, Mason County, IL, McDonough County, IL, McLean County, IL, Menard County, IL, Morgan County, IL, Moultrie County, IL, Peoria County, IL, Piatt County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Shelby County, IL, Tazewell County, IL, Vermilion County, IL, Warren County, IL, Woodford County, IL, Vermillion County, IN, Adair County, MO, Clark County, MO, Knox County, MO, Lewis County, MO, Marion County, MO, Schuyler County, MO, Scotland County, MO

The radar

The Lincoln radar (KILX), 52 km from the middle of the area, began a volume at 18:38 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, 6.7 hours before the alert went out and 111 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 2014-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 806 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, Lincoln, IL at 12:00Z on 2014-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 156 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
806 J/kg
Mixed-layer CIN
-144 J/kg
Mixed-layer LCL
1032 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
156 m²/s²
0-3 km storm-relative helicity
108 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.9

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 20, 8:06 PM CDTMesoscale DiscussionSPCDeKalb, DuPage, Grundy, Kane, Kankakee, Kendall and 1 more84 min
May 20, 9:56 PM CDTMesoscale DiscussionSPCCarroll, DeKalb, DuPage, Jo Daviess, Kane, Kendall and 4 more94 min
May 20, 11:23 PM CDTMesoscale DiscussionSPCCook, Lake97 min
May 21, 1:27 AM CDTMesoscale DiscussionSPCBureau, Carroll, Cook, DeKalb, DuPage, Grundy and 17 more93 min
May 21, 11:54 AM CDTMesoscale DiscussionSPCIroquois, Vermilion3 hr
May 21, 2:35 PM CDTSevere Thunderstorm WatchSPCChampaign, Clark, Coles, Cumberland, DeWitt, Douglas and 10 more5 hr
May 21, 3:12 PM CDTMesoscale DiscussionSPCBond, Calhoun, Champaign, Christian, Clark, Clay and 44 more2 hr
May 21, 5:03 PM CDTMesoscale DiscussionSPCEdwards, Franklin, Hamilton, Jefferson, Wabash, Washington and 2 more87 min
May 21, 5:28 PM CDTSevere Thunderstorm WatchSPCEdwards, Franklin, Gallatin, Hamilton, Hardin, Jefferson and 7 more13 hr
May 21, 6:50 PM CDTMesoscale DiscussionSPCChampaign, Clark, Douglas, Edgar, Vermilion85 min
May 20, 8:47 PM CDTSevere Thunderstorm WatchSPCAdams, Allen, Blackford, Cass, DeKalb, Elkhart and 18 more7 hr
May 21, 1:56 AM CDTMesoscale DiscussionSPCAdams, Allen, DeKalb, Elkhart, Fulton, Huntington and 12 more94 min
May 21, 3:26 AM CDTMesoscale DiscussionSPCAllen, DeKalb, Elkhart, Kosciusko, LaGrange, Marshall and 4 more34 min
May 21, 12:52 PM CDTSevere Thunderstorm WatchSPCBartholomew, Boone, Brown, Carroll, Clay, Clinton and 41 more9 hr

Nearby

Mesoscale Discussions in Illinois, 2014Mesoscale Discussions in Missouri, 2014Mesoscale Discussions in Indiana, 2014Every mesoscale discussion in 2014

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.