Alert archive / Mississippi / Mesoscale Discussions in 2008

Mesoscale Discussion 664

April 18, 2008Plaquemines Parish, Saint Bernard Parish, Louisiana; 4 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 18, 2008, 9:44 PM CDT for Plaquemines Parish, Saint Bernard Parish, Louisiana; 4 counties in Mississippi. It was in force for 31 min.

The area

The outline as issued.

The facts

Issued
Apr 18, 2008, 9:44 PM CDT (02:44 UTC)
Expired
Apr 18, 2008, 10:15 PM CDT
In force
31 min
Issued by
the Storm Prediction Center

Counties Plaquemines Parish, LA, Saint Bernard Parish, LA, George County, MS, Greene County, MS, Harrison County, MS, Jackson County, MS

The radar

The Mobile radar (KMOB), 120 km from the middle of the area, began a volume at 02:45 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

Slidell Radar S, LA (KSIL), launched 00:00Z, 2.7 hours before the alert went out and 80 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, Slidell Radar S, LA at 00:00Z on 2008-04-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 695 joules per kilogram.LCLLFCEL10008507005003002001001 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, Slidell Radar S, LA at 00:00Z on 2008-04-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 396 square meters per square second.19395878Sfc1 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
695 J/kg
Mixed-layer CIN
-12 J/kg
Mixed-layer LCL
712 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
396 m²/s²
0-3 km storm-relative helicity
515 m²/s²
Significant tornado parameter
1.8
Supercell composite
9.2

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
Apr 18, 8:33 PM CDTMesoscale DiscussionSPCJefferson, Lafourche, Orleans, Plaquemines, Saint Bernard57 min
Apr 18, 10:21 PM CDTMesoscale DiscussionSPCGeorge, Jackson54 min

Nearby

Mesoscale Discussions in Mississippi, 2008Mesoscale Discussions in Louisiana, 2008Every mesoscale discussion in 2008

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.