Alert archive / Minnesota / Mesoscale Discussions in 2016

Mesoscale Discussion 1727

September 21, 201621 counties in Minnesota; 19 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Sep 21, 2016, 2:31 PM CDT for 21 counties in Minnesota; 19 counties in Wisconsin. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued: Sep 21, 2016, 2:31 PM CDT (19:31 UTC)
Expired: Sep 21, 2016, 4:00 PM CDT
In force: 89 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

All 40 counties

Anoka County, MN, Carver County, MN, Chippewa County, MN, Chisago County, MN, Dakota County, MN, Goodhue County, MN, Hennepin County, MN, Isanti County, MN, Kandiyohi County, MN, McLeod County, MN, Meeker County, MN, Ramsey County, MN, Renville County, MN, Scott County, MN, Sherburne County, MN, Sibley County, MN, Stearns County, MN, Swift County, MN, Wabasha County, MN, Washington County, MN, Wright County, MN, Adams County, WI, Barron County, WI, Buffalo County, WI, Chippewa County, WI, Clark County, WI, Dunn County, WI, Eau Claire County, WI, Jackson County, WI, Juneau County, WI, Monroe County, WI, Pepin County, WI, Pierce County, WI, Polk County, WI, Portage County, WI, Rusk County, WI, Saint Croix County, WI, Taylor County, WI, Trempealeau County, WI, Wood County, WI

The radar

The Minneapolis radar (KMPX), 47 km from the middle of the area, began a volume at 19:30 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

Minneapolis, MN (KMPX), launched 12:00Z, 7.5 hours before the alert went out and 50 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: 515 J/kg
Mixed-layer CIN: -331 J/kg
Mixed-layer LCL: 738 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 17 m²/s²
0-3 km storm-relative helicity: 136 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 8.5

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 20, 8:01 PM CDT	Mesoscale Discussion	SPC	Blue Earth, Brown, Carver, Cottonwood, Dakota, Dodge and 21 more	119 min
Sep 20, 9:34 PM CDT	Severe Thunderstorm Watch	SPC	Blue Earth, Brown, Dodge, Faribault, Fillmore, Freeborn and 13 more	5 hr
Sep 20, 11:26 PM CDT	Mesoscale Discussion	SPC	Blue Earth, Dodge, Faribault, Fillmore, Freeborn, Goodhue and 10 more	2 hr
Sep 21, 1:33 AM CDT	Mesoscale Discussion	SPC	Blue Earth, Dakota, Dodge, Fillmore, Freeborn, Goodhue and 11 more	117 min
Sep 21, 2:00 PM CDT	Mesoscale Discussion	SPC	Blue Earth, Brown, Cottonwood, Dakota, Dodge, Faribault and 22 more	2 hr
Sep 21, 6:01 PM CDT	Mesoscale Discussion	SPC	Blue Earth, Brown, Carver, Cottonwood, Dakota, Dodge and 29 more	2 hr

Nearby

Mesoscale Discussions in Minnesota, 2016 Mesoscale Discussions in Wisconsin, 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.