Alert archive / Mississippi / Mesoscale Discussions in 2015

Mesoscale Discussion 1973

November 17, 20157 counties in Arkansas; 8 counties in Mississippi; Shelby County, Tipton County, Tennessee

The Storm Prediction Center issued this mesoscale discussion at Nov 17, 2015, 5:36 PM CST for 7 counties in Arkansas; 8 counties in Mississippi; Shelby County, Tipton County, Tennessee. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued: Nov 17, 2015, 5:36 PM CST (23:36 UTC)
Expired: Nov 17, 2015, 7:00 PM CST
In force: 84 min
Issued by: the Storm Prediction Center

Counties Crittenden County, AR, Cross County, AR, Lee County, AR, Monroe County, AR, Phillips County, AR, Poinsett County, AR, St. Francis County, AR, Coahoma County, MS, DeSoto County, MS, Panola County, MS, Quitman County, MS, Tallahatchie County, MS, Tate County, MS, Tunica County, MS, Yalobusha County, MS, Shelby County, TN, Tipton County, TN

The radar

The Memphis radar (KNQA), 107 km from the middle of the area, began a volume at 23:37 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 nearest sounding before it

Little Rock, AR (KBYH), launched 12:00Z, 11.6 hours before the alert went out and 66 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: 344 J/kg
Mixed-layer CIN: -23 J/kg
Mixed-layer LCL: 618 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 403 m²/s²
0-3 km storm-relative helicity: 550 m²/s²
Significant tornado parameter: 0.9
Supercell composite: 8.5

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
Nov 17, 4:35 AM CST	Mesoscale Discussion	SPC	Benton, Crawford, Franklin, Howard, Johnson, Logan and 9 more	115 min
Nov 17, 4:48 AM CST	Tornado Watch	SPC	Howard, Little River, Miller, Sevier	4 hr
Nov 17, 6:27 AM CST	Severe Thunderstorm Watch	SPC	Baxter, Benton, Boone, Carroll, Clark, Conway and 21 more	6 hr
Nov 17, 8:24 AM CST	Mesoscale Discussion	SPC	Columbia, Lafayette	66 min
Nov 17, 8:55 AM CST	Tornado Watch	SPC	Columbia, Hempstead, Howard, Lafayette, Little River, Miller and 3 more	7 hr
Nov 17, 9:59 AM CST	Mesoscale Discussion	SPC	Arkansas, Ashley, Baxter, Boone, Bradley, Calhoun and 58 more	2 hr
Nov 17, 11:07 AM CST	Tornado Watch	SPC	Arkansas, Bradley, Calhoun, Clark, Cleburne, Cleveland and 21 more	6 hr
Nov 17, 12:19 PM CST	Mesoscale Discussion	SPC	Ashley, Chicot	116 min
Nov 17, 12:36 PM CST	Tornado Watch	SPC	Ashley, Chicot	7 hr
Nov 17, 1:35 PM CST	Mesoscale Discussion	SPC	Arkansas, Cleburne, Cleveland, Craighead, Crittenden, Cross and 25 more	115 min
Nov 17, 3:15 PM CST	Tornado Watch	SPC	Craighead, Crittenden, Cross, Lee, Mississippi, Phillips and 2 more	4 hr
Nov 17, 3:19 PM CST	Mesoscale Discussion	SPC	Clay, Fulton, Greene, Izard, Lawrence, Randolph and 1 more	116 min

Nearby

Mesoscale Discussions in Mississippi, 2015 Mesoscale Discussions in Arkansas, 2015 Mesoscale Discussions in Tennessee, 2015 Every 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.