Alert archive / Louisiana / Mesoscale Discussions in 2017

Mesoscale Discussion 410

April 2, 201713 parishes in Louisiana; 4 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 2, 2017, 5:54 PM CDT for 13 parishes in Louisiana; 4 counties in Texas. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued
Apr 2, 2017, 5:54 PM CDT (22:54 UTC)
Expired
Apr 2, 2017, 7:30 PM CDT
In force
96 min
Issued by
the Storm Prediction Center

Counties Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, Evangeline Parish, LA, Grant Parish, LA, Jefferson Davis Parish, LA, LaSalle Parish, LA, Rapides Parish, LA, Vernon Parish, LA, Hardin County, TX, Jasper County, TX, Newton County, TX, Orange County, TX

The radar

The Ft Polk radar (KPOE), 39 km from the middle of the area, began a volume at 22:53 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 watches that followed

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

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 10.9 hours before the alert went out and 79 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, Lake Charles Mun, LA at 12:00Z on 2017-04-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2197 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, Lake Charles Mun, LA at 12:00Z on 2017-04-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 243 square meters per square second.193958Sfc1 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
2197 J/kg
Mixed-layer CIN
-14 J/kg
Mixed-layer LCL
489 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
243 m²/s²
0-3 km storm-relative helicity
317 m²/s²
Significant tornado parameter
3.3
Supercell composite
19.3

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.

IssuedProductOfficeCountiesLasted
Apr 2, 9:04 AM CDTMesoscale DiscussionSPCBeauregard, Sabine, Vernon2 hr
Apr 2, 9:05 AM CDTMesoscale DiscussionSPCAcadia, Ascension, East Baton Rouge, Iberville, Lafayette, Livingston and 5 more85 min
Apr 2, 10:39 AM CDTTornado WatchSPCBienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 13 more5 hr
Apr 2, 12:22 PM CDTMesoscale DiscussionSPCSabine83 min
Apr 2, 12:49 PM CDTMesoscale DiscussionSPCAvoyelles, Concordia, East Baton Rouge, East Carroll, East Feliciana, Franklin and 7 more116 min
Apr 2, 1:34 PM CDTTornado Watch PDSSPCAcadia, Allen, Avoyelles, Beauregard, Bienville, Calcasieu and 28 more7 hr
Apr 2, 2:06 PM CDTMesoscale DiscussionSPCGrant, LaSalle, Natchitoches, Rapides, Sabine, Vernon and 1 more54 min
Apr 2, 3:08 PM CDTMesoscale DiscussionSPCAscension, East Baton Rouge, East Feliciana, Livingston, Saint Charles, Saint Helena and 6 more3 hr
Apr 2, 3:13 PM CDTMesoscale DiscussionSPCAllen, Avoyelles, Beauregard, Caldwell, Catahoula, Concordia and 13 more92 min
Apr 2, 4:52 PM CDTTornado WatchSPCAscension, Concordia, East Baton Rouge, East Feliciana, Iberville, Livingston and 8 more9 hr
Apr 1, 7:20 PM CDTMesoscale DiscussionSPCVal Verde85 min
Apr 1, 8:44 PM CDTMesoscale DiscussionSPCBrown, Callahan, Coleman, Comanche, Concho, Eastland and 5 more61 min
Apr 1, 10:06 PM CDTMesoscale DiscussionSPCBandera, Bexar, Blanco, Comal, Edwards, Gillespie and 9 more114 min
Apr 1, 10:28 PM CDTTornado WatchSPCBandera, Edwards, Gillespie, Kerr, Kimble, Kinney and 6 more8 hr
Apr 2, 2:53 AM CDTMesoscale DiscussionSPCBandera, Edwards, Gillespie, Kerr, Kimble, Kinney and 6 more82 min
Apr 2, 5:16 AM CDTMesoscale DiscussionSPCAnderson, Angelina, Bandera, Bastrop, Bell, Bexar and 51 more119 min
Apr 2, 6:00 AM CDTTornado WatchSPCAnderson, Atascosa, Bandera, Bastrop, Bell, Bexar and 51 more7 hr
Apr 2, 9:44 AM CDTMesoscale DiscussionSPCAustin, Bastrop, Brazos, Burleson, Caldwell, Cherokee and 19 more2 hr
Apr 2, 4:23 PM CDTMesoscale DiscussionSPCAransas, Brazoria, Calhoun, Cameron, Jackson, Kenedy and 5 more3 hr

Nearby

Mesoscale Discussions in Louisiana, 2017Mesoscale Discussions in Texas, 2017Every mesoscale discussion in 2017

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.