Alert archive / Louisiana / Mesoscale Discussions in 2019

Mesoscale Discussion 142

March 3, 201913 parishes in Louisiana

The Storm Prediction Center issued this mesoscale discussion at Mar 3, 2019, 10:35 AM CST for 13 parishes in Louisiana. It was in force for 25 min.

The area

The outline as issued.

The facts

Issued: Mar 3, 2019, 10:35 AM CST (16:35 UTC)
Expired: Mar 3, 2019, 11:00 AM CST
In force: 25 min
Issued by: the Storm Prediction Center
Chance of a watch: 80%

Counties Ascension Parish, LA, Assumption Parish, LA, East Baton Rouge Parish, LA, Iberville Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Martin Parish, LA, Saint Tammany Parish, LA, Tangipahoa Parish, LA, West Baton Rouge Parish, LA

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Tornado Watch 7Mar 3, 11:40 AM CST

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 4.6 hours before the alert went out and 115 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: 490 J/kg
Mixed-layer CIN: -29 J/kg
Mixed-layer LCL: 469 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 197 m²/s²
0-3 km storm-relative helicity: 235 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.6

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
Mar 3, 11:03 AM CST	Tornado Watch	SPC	Livingston, Saint Helena, Saint Tammany, Tangipahoa, Washington	7 hr
Mar 3, 1:20 PM CST	Mesoscale Discussion	SPC	Tangipahoa, Washington	115 min

Nearby

Mesoscale Discussions in Louisiana, 2019 Every mesoscale discussion in 2019

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.