Alert archive / Kentucky / Mesoscale Discussions in 2015

Mesoscale Discussion 1499

July 20, 20156 states

The Storm Prediction Center issued this mesoscale discussion at Jul 20, 2015, 10:11 PM CDT for 6 states. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued: Jul 20, 2015, 10:11 PM CDT (03:11 UTC)
Expired: Jul 20, 2015, 11:15 PM CDT
In force: 64 min
Issued by: the Storm Prediction Center

All 48 counties

Clay County, AR, Craighead County, AR, Greene County, AR, Lawrence County, AR, Gallatin County, IL, Hardin County, IL, Massac County, IL, Pope County, IL, Saline County, IL, White County, IL, Dubois County, IN, Gibson County, IN, Pike County, IN, Posey County, IN, Spencer County, IN, Vanderburgh County, IN, Warrick County, IN, Ballard County, KY, Caldwell County, KY, Calloway County, KY, Carlisle County, KY, Christian County, KY, Crittenden County, KY, Daviess County, KY, Fulton County, KY, Graves County, KY, Hancock County, KY, Henderson County, KY, Hickman County, KY, Hopkins County, KY, Livingston County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, McLean County, KY, Muhlenberg County, KY, Ohio County, KY, Trigg County, KY, Union County, KY, Webster County, KY, Dunklin County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Henry County, TN, Lake County, TN, Obion County, TN, Weakley County, TN

The radar

The Paducah radar (KPAH), 12 km from the middle of the area, began a volume at 03:14 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

Nashville Metro, TN (KBNA), launched 00:00Z, 3.2 hours before the alert went out and 208 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: 1631 J/kg
Mixed-layer CIN: -12 J/kg
Mixed-layer LCL: 1303 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 54 m²/s²
0-3 km storm-relative helicity: 130 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 2.6

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 20, 8:28 PM CDT	Mesoscale Discussion	SPC	Clay, Randolph	92 min

Nearby

Mesoscale Discussions in Kentucky, 2015 Mesoscale Discussions in Indiana, 2015 Mesoscale Discussions in Illinois, 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.