Alert archive / Illinois / Mesoscale Discussions in 2007

Mesoscale Discussion 1516

July 18, 200716 counties in Illinois; 15 counties in Indiana

The Storm Prediction Center issued this mesoscale discussion at Jul 18, 2007, 4:21 AM CDT for 16 counties in Illinois; 15 counties in Indiana. It was in force for 54 min.

The area

The outline as issued.

The facts

Issued: Jul 18, 2007, 4:21 AM CDT (09:21 UTC)
Expired: Jul 18, 2007, 5:15 AM CDT
In force: 54 min
Issued by: the Storm Prediction Center

All 31 counties

Clark County, IL, Clay County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, Douglas County, IL, Edgar County, IL, Edwards County, IL, Effingham County, IL, Jasper County, IL, Lawrence County, IL, Moultrie County, IL, Piatt County, IL, Richland County, IL, Shelby County, IL, Wabash County, IL, Clay County, IN, Daviess County, IN, Dubois County, IN, Gibson County, IN, Greene County, IN, Knox County, IN, Martin County, IN, Owen County, IN, Parke County, IN, Pike County, IN, Sullivan County, IN, Vanderburgh County, IN, Vermillion County, IN, Vigo County, IN, Warrick County, IN

The radar

The Evansville,IN radar (KVWX), 99 km from the middle of the area, began a volume at 09:22 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 nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 9.4 hours before the alert went out and 128 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 46 J/kg
Mixed-layer CIN: -310 J/kg
Mixed-layer LCL: 1165 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 124 m²/s²
0-3 km storm-relative helicity: 119 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.

Issued	Product	Office	Counties	Lasted
Jul 17, 9:31 PM CDT	Severe Thunderstorm Watch	SPC	Boone, Carroll, DeKalb, Jo Daviess, Lee, Ogle and 3 more	6 hr
Jul 17, 11:24 PM CDT	Mesoscale Discussion	SPC	Bureau, Carroll, DeKalb, Henderson, Henry, Jo Daviess and 15 more	96 min
Jul 18, 3:35 AM CDT	Mesoscale Discussion	SPC	Boone, Carroll, DeKalb, Jo Daviess, Kane, Lee and 5 more	85 min
Jul 18, 4:59 PM CDT	Mesoscale Discussion	SPC	Boone, Bureau, Carroll, Champaign, Cook, DeKalb and 32 more	91 min
Jul 18, 5:35 PM CDT	Severe Thunderstorm Watch	SPC	Boone, Bureau, Carroll, DeKalb, DeWitt, Fulton and 25 more	6 hr
Jul 18, 6:38 PM CDT	Mesoscale Discussion	SPC	Champaign, Cook, Douglas, DuPage, Edgar, Ford and 11 more	97 min
Jul 18, 6:50 PM CDT	Mesoscale Discussion	SPC	Boone, Bureau, Carroll, DeKalb, Henderson, Henry and 18 more	85 min

Nearby

Mesoscale Discussions in Illinois, 2007 Mesoscale Discussions in Indiana, 2007 Every mesoscale discussion in 2007

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.