Alert archive / Illinois / Mesoscale Discussions in 2007

Mesoscale Discussion 457

April 11, 200725 counties in Illinois; 19 counties in Indiana; 11 counties in Kentucky

The Storm Prediction Center issued this mesoscale discussion at Apr 11, 2007, 2:04 PM CDT for 25 counties in Illinois; 19 counties in Indiana; 11 counties in Kentucky. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued: Apr 11, 2007, 2:04 PM CDT (19:04 UTC)
Expired: Apr 11, 2007, 3:30 PM CDT
In force: 86 min
Issued by: the Storm Prediction Center

All 55 counties

Champaign County, IL, Clark County, IL, Clay County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Edwards County, IL, Effingham County, IL, Gallatin County, IL, Jasper County, IL, Lawrence County, IL, Logan County, IL, Macon County, IL, McLean County, IL, Moultrie County, IL, Piatt County, IL, Richland County, IL, Shelby County, IL, Vermilion County, IL, Wabash County, IL, Wayne County, IL, White County, IL, Clay County, IN, Daviess County, IN, Dubois County, IN, Gibson County, IN, Greene County, IN, Knox County, IN, Martin County, IN, Monroe County, IN, Owen County, IN, Parke County, IN, Pike County, IN, Posey County, IN, Putnam County, IN, Spencer County, IN, Sullivan County, IN, Vanderburgh County, IN, Vermillion County, IN, Vigo County, IN, Warrick County, IN, Caldwell County, KY, Crittenden County, KY, Daviess County, KY, Hancock County, KY, Henderson County, KY, Hopkins County, KY, Lyon County, KY, McLean County, KY, Muhlenberg County, KY, Union County, KY, Webster County, KY

The radar

The Evansville,IN radar (KVWX), 57 km from the middle of the area, began a volume at 19:03 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.

Severe Thunderstorm Watch 126Apr 11, 4:30 PM CDT

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 7.1 hours before the alert went out and 166 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 520 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 252 m²/s²
0-3 km storm-relative helicity: 257 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
Apr 11, 7:30 AM CDT	Mesoscale Discussion	SPC	Jo Daviess, Stephenson, Winnebago	6 hr
Apr 11, 4:28 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Bartholomew, Benton, Blackford, Boone, Brown and 62 more	4 hr
Apr 11, 5:50 PM CDT	Mesoscale Discussion	SPC	Adams, Allen, Bartholomew, Blackford, Boone, Cass and 32 more	55 min
Apr 11, 6:16 PM CDT	Severe Thunderstorm Watch	SPC	Bath, Bourbon, Boyd, Bracken, Campbell, Carter and 18 more	5 hr

Nearby

Mesoscale Discussions in Illinois, 2007 Mesoscale Discussions in Indiana, 2007 Mesoscale Discussions in Kentucky, 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.