Alert archive / Louisiana / Mesoscale Discussions in 2020

Mesoscale Discussion 559

May 8, 202010 parishes in Louisiana

The Storm Prediction Center issued this mesoscale discussion at May 8, 2020, 2:47 PM CDT for 10 parishes in Louisiana. It was in force for 118 min.

The area

The outline as issued.

The facts

Issued: May 8, 2020, 2:47 PM CDT (19:47 UTC)
Expired: May 8, 2020, 4:45 PM CDT
In force: 118 min
Issued by: the Storm Prediction Center

Counties Acadia Parish, LA, Assumption Parish, LA, Calcasieu Parish, LA, Iberville Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, Saint James Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, St. Mary Parish, LA

The radar

The Lake Charles radar (KLCH), 115 km from the middle of the area, began a volume at 19:47 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

Lake Charles Mun, LA (KLCH), launched 12:00Z, 7.8 hours before the alert went out and 113 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: 590 J/kg
Mixed-layer CIN: -306 J/kg
Mixed-layer LCL: 754 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 180 m²/s²
0-3 km storm-relative helicity: 410 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

<!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 8, 3:06 AM CDT	Severe Thunderstorm Watch	SPC	Bienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 11 more	7 hr
May 8, 5:22 AM CDT	Mesoscale Discussion	SPC	Bienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 11 more	83 min
May 8, 9:30 AM CDT	Mesoscale Discussion	SPC	Acadia, Allen, Ascension, Avoyelles, Beauregard, Catahoula and 27 more	2 hr
May 8, 1:36 PM CDT	Severe Thunderstorm Watch	SPC	Acadia, Allen, Ascension, Assumption, Beauregard, Calcasieu and 19 more	6 hr

Nearby

Mesoscale Discussions in Louisiana, 2020 Every mesoscale discussion in 2020

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.