Alert archive / Florida / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 20, NWS Miami, FL

April 28, 1999Hendry County, Palm Beach County, Florida

NWS Miami, FL issued this severe thunderstorm warning at Apr 28, 1999, 10:40 AM EDT for Hendry County, Palm Beach County, Florida. It was in force for 50 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Apr 28, 1999, 10:40 AM EDT (14:40 UTC)
Expired: Apr 28, 1999, 11:30 AM EDT
In force: 50 min
Issued by: NWS Miami, FL
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Hendry County, FL, Palm Beach County, FL

The radar

The Miami radar (KAMX), 117 km from the middle of the area, began a volume at 14:41 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

Miami, FL (KMFL), launched 12:00Z, 2.7 hours before the alert went out and 101 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: 384 J/kg
Mixed-layer CIN: -46 J/kg
Mixed-layer LCL: 1060 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 93 m²/s²
0-3 km storm-relative helicity: 109 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 3.4

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, Apr 28, 5:45 AM EDT, 4 hours 55 minutes before

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Special weather statement, Apr 28, 5:45 AM EDT, 4 hours 55 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 Miami, FL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 28, 12:12 PM EDT	Severe Thunderstorm Warning	MFL	Broward, Collier	43 min
Apr 28, 2:51 PM EDT	Severe Thunderstorm Warning	MFL	Broward, Collier	39 min
Apr 28, 3:10 PM EDT	Severe Thunderstorm Warning	MFL	Broward	35 min
Apr 28, 3:38 PM EDT	Severe Thunderstorm Warning	MFL	Miami-Dade	52 min
Apr 28, 3:45 PM EDT	Severe Thunderstorm Warning	MFL	Broward	15 min

Nearby

Severe Thunderstorm Warnings in Florida, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.