Alert archive / Montana / Mesoscale Discussions in 2013

Mesoscale Discussion 812

May 26, 201310 counties in Montana; 4 counties in Wyoming

The Storm Prediction Center issued this mesoscale discussion at May 26, 2013, 6:08 PM MDT for 10 counties in Montana; 4 counties in Wyoming. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: May 26, 2013, 6:08 PM MDT (00:08 UTC)
Expired: May 26, 2013, 8:15 PM MDT
In force: 2 hr
Issued by: the Storm Prediction Center

Counties Big Horn County, MT, Custer County, MT, Fergus County, MT, Garfield County, MT, Musselshell County, MT, Petroleum County, MT, Powder River County, MT, Rosebud County, MT, Treasure County, MT, Yellowstone County, MT, Campbell County, WY, Crook County, WY, Johnson County, WY, Sheridan County, WY

The radar

The Billings radar (KBLX), 154 km from the middle of the area, began a volume at 00:10 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

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 0.1 hours before the alert went out and 225 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: 7 J/kg
Mixed-layer CIN: -77 J/kg
Mixed-layer LCL: 2432 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 6 m²/s²
0-3 km storm-relative helicity: 87 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

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 26, 9:31 PM MDT	Mesoscale Discussion	SPC	Big Horn, Carter, Custer, McCone, Powder River, Prairie and 2 more	119 min
May 27, 11:36 AM MDT	Mesoscale Discussion	SPC	Carter	54 min
May 27, 11:51 AM MDT	Severe Thunderstorm Watch	SPC	Big Horn, Carter, Custer, Fallon, Powder River, Rosebud and 1 more	10 hr
May 27, 3:52 PM MDT	Mesoscale Discussion	SPC	Carter, Custer, Fallon, Powder River, Prairie, Wibaux	83 min

Nearby

Mesoscale Discussions in Montana, 2013 Mesoscale Discussions in Wyoming, 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.