Alert archive / Indiana / Mesoscale Discussions in 2013

Mesoscale Discussion 918

May 31, 2013Iroquois County, Illinois; 28 counties in Indiana

The Storm Prediction Center issued this mesoscale discussion at May 31, 2013, 9:47 PM CDT for Iroquois County, Illinois; 28 counties in Indiana. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued: May 31, 2013, 9:47 PM CDT (02:47 UTC)
Expired: May 31, 2013, 10:45 PM CDT
In force: 58 min
Issued by: the Storm Prediction Center
Chance of a watch: 80%

All 29 counties

Iroquois County, IL, Bartholomew County, IN, Benton County, IN, Boone County, IN, Brown County, IN, Carroll County, IN, Clay County, IN, Clinton County, IN, Fountain County, IN, Hamilton County, IN, Hancock County, IN, Hendricks County, IN, Henry County, IN, Howard County, IN, Johnson County, IN, Madison County, IN, Marion County, IN, Monroe County, IN, Montgomery County, IN, Morgan County, IN, Owen County, IN, Parke County, IN, Putnam County, IN, Rush County, IN, Shelby County, IN, Tippecanoe County, IN, Tipton County, IN, Warren County, IN, White County, IN

The radar

The Indianapolis radar (KIND), 50 km from the middle of the area, began a volume at 02:49 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.

Tornado Watch 267May 31, 10:10 PM CDT

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 2.8 hours before the alert went out and 155 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: 2269 J/kg
Mixed-layer CIN: -6 J/kg
Mixed-layer LCL: 706 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: 228 m²/s²
0-3 km storm-relative helicity: 244 m²/s²
Significant tornado parameter: 3.6
Supercell composite: 15.2

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
May 31, 7:05 PM CDT	Mesoscale Discussion	SPC	Bond, Calhoun, Christian, Greene, Jersey, Macon and 5 more	85 min
May 31, 7:23 PM CDT	Tornado Watch	SPC	Champaign, Christian, Clark, Clay, Coles, Crawford and 12 more	6 hr
May 31, 8:46 PM CDT	Mesoscale Discussion	SPC	Bond, Clay, Clinton, Coles, Cumberland, Effingham and 16 more	59 min
May 31, 9:37 PM CDT	Tornado Watch	SPC	Alexander, Clinton, Edwards, Franklin, Gallatin, Hamilton and 19 more	6 hr
May 31, 10:11 PM CDT	Tornado Watch	SPC	Ford, Iroquois	5 hr
Jun 1, 1:13 AM CDT	Mesoscale Discussion	SPC	Crawford, Lawrence, Wabash	2 hr
Jun 1, 1:51 AM CDT	Mesoscale Discussion	SPC	Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 14 more	114 min
Jun 1, 3:46 AM CDT	Mesoscale Discussion	SPC	Massac	29 min
Jun 1, 1:24 PM CDT	Mesoscale Discussion	SPC	Dearborn, Ohio, Switzerland	96 min

Nearby

Mesoscale Discussions in Indiana, 2013 Mesoscale Discussions in Illinois, 2013 Every mesoscale discussion in 2013

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.