Alert archive / Illinois / Mesoscale Discussions in 2009

Mesoscale Discussion 1202

June 18, 200915 counties in Illinois; 14 counties in Iowa

The Storm Prediction Center issued this mesoscale discussion at Jun 18, 2009, 9:42 AM CDT for 15 counties in Illinois; 14 counties in Iowa. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued
Jun 18, 2009, 9:42 AM CDT (14:42 UTC)
Expired
Jun 18, 2009, 11:15 AM CDT
In force
93 min
Issued by
the Storm Prediction Center
All 29 counties

Benton County, IA, Buchanan County, IA, Cedar County, IA, Clinton County, IA, Delaware County, IA, Dubuque County, IA, Iowa County, IA, Jackson County, IA, Johnson County, IA, Jones County, IA, Linn County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Bureau County, IL, Carroll County, IL, Henderson County, IL, Henry County, IL, Knox County, IL, LaSalle County, IL, Lee County, IL, Marshall County, IL, Mercer County, IL, Peoria County, IL, Putnam County, IL, Rock Island County, IL, Stark County, IL, Warren County, IL, Whiteside County, IL

The radar

The Quad Cities radar (KDVN), 15 km from the middle of the area, began a volume at 14:44 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

Davenport, (KDVN), launched 12:00Z, 2.7 hours before the alert went out and 18 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, Davenport, at 12:00Z on 2009-06-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 98 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, Davenport, at 12:00Z on 2009-06-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -56 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
98 J/kg
Mixed-layer CIN
-444 J/kg
Mixed-layer LCL
1141 m above ground
0-6 km bulk shear
62 kt
0-1 km storm-relative helicity
-56 m²/s²
0-3 km storm-relative helicity
57 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
Jun 17, 11:53 PM CDTSevere Thunderstorm WatchSPCHancock, Henderson, McDonough, Mercer, Rock Island, Warren6 hr
Jun 18, 1:01 AM CDTMesoscale DiscussionSPCAdams, Brown, Calhoun, Cass, Fulton, Greene and 11 more89 min
Jun 18, 3:20 AM CDTMesoscale DiscussionSPCAdams, Brown, Cass, Christian, DeWitt, Douglas and 27 more85 min
Jun 18, 4:12 AM CDTSevere Thunderstorm WatchSPCCass, Champaign, Christian, Clark, Clay, Coles and 29 more5 hr
Jun 18, 6:09 AM CDTMesoscale DiscussionSPCClark, Clay, Coles, Crawford, Cumberland, Edgar and 15 more2 hr
Jun 18, 6:30 AM CDTSevere Thunderstorm WatchSPCEdwards, Gallatin, Hamilton, Wabash, Wayne, White6 hr
Jun 18, 10:11 AM CDTSevere Thunderstorm WatchSPCBureau, Carroll, DeWitt, Ford, Fulton, Grundy and 21 more6 hr
Jun 18, 1:17 PM CDTMesoscale DiscussionSPCBureau, Carroll, Fulton, Henderson, Henry, Knox and 17 more88 min
Jun 17, 7:01 PM CDTTornado WatchSPCAllamakee, Bremer, Butler, Cerro Gordo, Chickasaw, Clayton and 12 more5 hr
Jun 17, 8:04 PM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Cass, Fremont, Guthrie and 8 more56 min
Jun 17, 9:04 PM CDTTornado WatchSPCFremont, Mills, Montgomery, Page, Pottawattamie3 hr
Jun 17, 11:07 PM CDTMesoscale DiscussionSPCAllamakee, Chickasaw, Clayton, Fayette, Howard, Winneshiek53 min
Jun 17, 11:33 PM CDTMesoscale DiscussionSPCFremont, Mills, Pottawattamie87 min
Jun 18, 4:20 AM CDTSevere Thunderstorm WatchSPCBuena Vista, Cherokee, Clay, Dickinson, Ida, Lyon and 5 more4 hr
Jun 18, 6:41 AM CDTMesoscale DiscussionSPCBlack Hawk, Boone, Bremer, Buchanan, Buena Vista, Butler and 31 more94 min
Jun 18, 7:04 AM CDTSevere Thunderstorm WatchSPCBlack Hawk, Bremer, Butler, Calhoun, Cerro Gordo, Chickasaw and 20 more4 hr
Jun 18, 3:15 PM CDTMesoscale DiscussionSPCBlack Hawk, Boone, Bremer, Buena Vista, Butler, Calhoun and 25 more90 min
Jun 18, 6:52 PM CDTMesoscale DiscussionSPCLyon, Sioux113 min

Nearby

Mesoscale Discussions in Illinois, 2009Mesoscale Discussions in Iowa, 2009Every mesoscale discussion in 2009

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.