Alert archive / Iowa / Mesoscale Discussions in 2016

Mesoscale Discussion 1640

September 5, 20164 states

The Storm Prediction Center issued this mesoscale discussion at Sep 5, 2016, 1:10 AM CDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Sep 5, 2016, 1:10 AM CDT (06:10 UTC)
Expired: Sep 5, 2016, 3:15 AM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

Counties Lyon County, IA, O'Brien County, IA, Osceola County, IA, Plymouth County, IA, Sioux County, IA, Cottonwood County, MN, Murray County, MN, Nobles County, MN, Dakota County, NE, Dixon County, NE, Thurston County, NE, Union County, SD

The radar

The Sioux Falls radar (KFSD), 73 km from the middle of the area, began a volume at 06:14 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

Omaha, NE (KOAX), launched 00:00Z, 6.2 hours before the alert went out and 196 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: 484 J/kg
Mixed-layer CIN: -182 J/kg
Mixed-layer LCL: 1048 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 220 m²/s²
0-3 km storm-relative helicity: 482 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 3.2

Open this sounding in Storm Lab

The text

As transmitted.

<!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
Sep 4, 10:40 PM CDT	Severe Thunderstorm Watch	SPC	Lyon, Plymouth, Sioux	4 hr
Sep 4, 9:16 PM CDT	Mesoscale Discussion	SPC	Wilkin	59 min
Sep 5, 3:08 PM CDT	Mesoscale Discussion	SPC	Chippewa, Kandiyohi, Lac qui Parle, Lincoln, Lyon, McLeod and 8 more	2 hr
Sep 4, 7:50 PM CDT	Mesoscale Discussion	SPC	Blaine, Buffalo, Custer, Dawson, Logan, Loup and 2 more	115 min
Sep 4, 8:57 PM CDT	Mesoscale Discussion	SPC	Arthur, Chase, Cherry, Dundy, Frontier, Grant and 10 more	93 min
Sep 5, 3:30 PM CDT	Mesoscale Discussion	SPC	Frontier, Furnas, Gosper, Harlan, Hitchcock, Phelps and 1 more	90 min
Sep 5, 6:06 PM CDT	Mesoscale Discussion	SPC	Antelope, Blaine, Boone, Buffalo, Custer, Dawson and 18 more	84 min
Sep 5, 6:09 PM CDT	Mesoscale Discussion	SPC	Box Butte, Dawes, Garden, Morrill, Scotts Bluff, Sioux	3 hr

Nearby

Mesoscale Discussions in Iowa, 2016 Mesoscale Discussions in Minnesota, 2016 Mesoscale Discussions in Nebraska, 2016 Every mesoscale discussion in 2016

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.