Alert archive / Minnesota / Mesoscale Discussions in 2018

Mesoscale Discussion 1397

August 31, 201816 counties in Minnesota

The Storm Prediction Center issued this mesoscale discussion at Aug 31, 2018, 2:00 PM CDT for 16 counties in Minnesota. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Aug 31, 2018, 2:00 PM CDT (19:00 UTC)
Expired: Aug 31, 2018, 4:30 PM CDT
In force: 3 hr
Issued by: the Storm Prediction Center
Chance of a watch: 40%

Counties Becker County, MN, Beltrami County, MN, Clay County, MN, Clearwater County, MN, Hubbard County, MN, Itasca County, MN, Koochiching County, MN, Lake of the Woods County, MN, Mahnomen County, MN, Marshall County, MN, Norman County, MN, Pennington County, MN, Polk County, MN, Red Lake County, MN, Roseau County, MN, Wilkin County, MN

The radar

The Fargo/Grand Forks radar (KMVX), 206 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 361Aug 31, 2:20 PM CDT

The nearest sounding before it

International Fa, MN (KINL), launched 12:00Z, 7.0 hours before the alert went out and 118 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: 1301 J/kg
Mixed-layer CIN: -120 J/kg
Mixed-layer LCL: 617 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 175 m²/s²
0-3 km storm-relative helicity: 306 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

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
Aug 31, 2:19 PM CDT	Severe Thunderstorm Watch	SPC	Beltrami, Clearwater, Itasca, Koochiching, Lake of the Woods	2 hr
Aug 31, 6:55 PM CDT	Severe Thunderstorm Watch	SPC	Aitkin, Carlton, Lake, Pine, Saint Louis	5 hr

Nearby

Mesoscale Discussions in Minnesota, 2018 Every mesoscale discussion in 2018

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.