Alert archive / South Dakota / Mesoscale Discussions in 2015

Mesoscale Discussion 1448

July 17, 201521 counties in Nebraska; 22 counties in South Dakota; 4 counties in Wyoming

The Storm Prediction Center issued this mesoscale discussion at Jul 17, 2015, 2:36 PM MDT for 21 counties in Nebraska; 22 counties in South Dakota; 4 counties in Wyoming. It was in force for 54 min.

The area

The outline as issued.

The facts

Issued
Jul 17, 2015, 2:36 PM MDT (20:36 UTC)
Expired
Jul 17, 2015, 3:30 PM MDT
In force
54 min
Issued by
the Storm Prediction Center
Chance of a watch
80%
All 47 counties

Arthur County, NE, Banner County, NE, Blaine County, NE, Box Butte County, NE, Brown County, NE, Cherry County, NE, Dawes County, NE, Garden County, NE, Grant County, NE, Hooker County, NE, Keith County, NE, Keya Paha County, NE, Logan County, NE, Loup County, NE, McPherson County, NE, Morrill County, NE, Rock County, NE, Scotts Bluff County, NE, Sheridan County, NE, Sioux County, NE, Thomas County, NE, Bennett County, SD, Brule County, SD, Buffalo County, SD, Custer County, SD, Fall River County, SD, Gregory County, SD, Haakon County, SD, Hughes County, SD, Hyde County, SD, Jackson County, SD, Jones County, SD, Lawrence County, SD, Lyman County, SD, Meade County, SD, Mellette County, SD, Oglala Lakota County, SD, Pennington County, SD, Stanley County, SD, Sully County, SD, Todd County, SD, Tripp County, SD, Ziebach County, SD, Converse County, WY, Goshen County, WY, Niobrara County, WY, Weston County, WY

The radar

The North Platte radar (KLNX), 134 km from the middle of the area, began a volume at 20:37 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.

The nearest sounding before it

Rapid City, SD (KRAP), launched 12:00Z, 8.6 hours before the alert went out and 170 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-pSkew-T log-p diagram, Rapid City, SD at 12:00Z on 2015-07-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Rapid City, SD at 12:00Z on 2015-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 130 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1565 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
130 m²/s²
0-3 km storm-relative helicity
296 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.

IssuedProductOfficeCountiesLasted
Jul 17, 3:03 PM MDTSevere Thunderstorm WatchSPCArthur, Banner, Blaine, Box Butte, Brown, Buffalo and 34 more8 hr
Jul 17, 4:43 PM MDTMesoscale DiscussionSPCAntelope, Boone, Cedar, Colfax, Cuming, Dixon and 12 more92 min
Jul 17, 5:02 PM MDTMesoscale DiscussionSPCArthur, Banner, Blaine, Box Butte, Brown, Chase and 28 more118 min
Jul 17, 12:10 PM MDTMesoscale DiscussionSPCBeadle, Brookings, Brown, Clark, Codington, Day and 17 more2 hr
Jul 17, 2:43 PM MDTSevere Thunderstorm WatchSPCBeadle, Brookings, Brown, Buffalo, Campbell, Clark and 21 more7 hr
Jul 16, 7:09 PM MDTMesoscale DiscussionSPCSheridan96 min
Jul 17, 3:45 PM MDTMesoscale DiscussionSPCAlbany, Carbon, Converse, Laramie, Natrona, Platte and 1 more60 min

Nearby

Mesoscale Discussions in South Dakota, 2015Mesoscale Discussions in Nebraska, 2015Mesoscale Discussions in Wyoming, 2015Every mesoscale discussion in 2015

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.