Alert archive / South Dakota / Mesoscale Discussions in 2011

Mesoscale Discussion 1473

July 2, 20114 states

The Storm Prediction Center issued this mesoscale discussion at Jul 2, 2011, 4:59 PM MDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jul 2, 2011, 4:59 PM MDT (22:59 UTC)
Expired: Jul 2, 2011, 7:00 PM MDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 24 counties

Carter County, MT, Custer County, MT, Powder River County, MT, Banner County, NE, Box Butte County, NE, Dawes County, NE, Morrill County, NE, Scotts Bluff County, NE, Sioux County, NE, Butte County, SD, Custer County, SD, Fall River County, SD, Harding County, SD, Lawrence County, SD, Meade County, SD, Oglala Lakota County, SD, Pennington County, SD, Campbell County, WY, Converse County, WY, Crook County, WY, Goshen County, WY, Niobrara County, WY, Platte County, WY, Weston County, WY

The radar

The Rapid City radar (KUDX), 112 km from the middle of the area, began a volume at 22:59 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

Rapid City, SD (KUNR), launched 12:00Z, 11.0 hours before the alert went out and 105 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: 829 J/kg
Mixed-layer CIN: -69 J/kg
Mixed-layer LCL: 993 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: -3 m²/s²
0-3 km storm-relative helicity: 41 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
Jul 2, 12:17 PM MDT	Mesoscale Discussion	SPC	Carter, Custer, Dawson, Fallon, Powder River, Prairie and 2 more	58 min
Jul 2, 2:13 PM MDT	Tornado Watch	SPC	Big Horn, Carter, Custer, Fallon, Powder River, Rosebud and 1 more	8 hr
Jul 2, 3:20 PM MDT	Severe Thunderstorm Watch	SPC	Dundy, Hitchcock, Red Willow	9 hr

Nearby

Mesoscale Discussions in South Dakota, 2011 Mesoscale Discussions in Wyoming, 2011 Mesoscale Discussions in Nebraska, 2011 Every mesoscale discussion in 2011

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.