Alert archive / Louisiana / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 138, NWS New Orleans, LA

May 27, 1999Lafourche Parish, Terrebonne Parish, Louisiana

NWS New Orleans, LA issued this severe thunderstorm warning at May 27, 1999, 3:17 PM CDT for Lafourche Parish, Terrebonne Parish, Louisiana. It was in force for 48 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: May 27, 1999, 3:17 PM CDT (20:17 UTC)
Expired: May 27, 1999, 4:05 PM CDT
In force: 48 min
Issued by: NWS New Orleans, LA
Area: Whole counties

Counties Lafourche Parish, LA, Terrebonne Parish, LA

What was reported inside it

Time	Report	Where	Remark
May 27, 3:45 PM CDT	Tornado F0	Valentine, LA

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 8.3 hours before the alert went out and 261 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: 421 J/kg
Mixed-layer CIN: -117 J/kg
Mixed-layer LCL: 1097 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 2 m²/s²
0-3 km storm-relative helicity: 26 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, May 27, 10:15 AM CDT, 5 hours 2 minutes before

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Special weather statement, May 27, 10:15 AM CDT, 5 hours 2 minutes before

<!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.
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The office that day

Everything else NWS New Orleans, LA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 27, 3:59 PM CDT	Severe Thunderstorm Warning	LIX	Lafourche	31 min
May 27, 4:26 PM CDT	Severe Thunderstorm Warning	LIX	Jefferson, Lafourche	49 min
May 27, 4:36 PM CDT	Tornado Warning	LIX	Jefferson, Plaquemines	19 min
May 27, 4:36 PM CDT	Tornado Warning	LIX	Lafourche	19 min
May 27, 5:00 PM CDT	Tornado Warning	LIX	Plaquemines	45 min

Nearby

Severe Thunderstorm Warnings in Louisiana, 1999 Every severe thunderstorm warning in 1999

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.