Alert archive / Florida / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 76, NWS Jacksonville, FL

April 28, 1999Marion County, Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at Apr 28, 1999, 4:44 PM EDT for Marion County, Florida. It was in force for 46 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
Apr 28, 1999, 4:44 PM EDT (20:44 UTC)
Expired
Apr 28, 1999, 5:30 PM EDT
In force
46 min
Issued by
NWS Jacksonville, FL
Area
Whole counties

County Marion County, FL

The radar

The Jacksonville radar (KJAX), 146 km from the middle of the area, began a volume at 20:46 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.

What was reported inside it

TimeReportWhereRemark
Apr 28, 5:00 PM EDTThunderstorm WindCitra, FLLarge trees and power lines were blown down.

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

Jacksonville, FL (KJAX), launched 12:00Z, 8.7 hours before the alert went out and 148 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, Jacksonville, FL at 12:00Z on 1999-04-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 746 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, Jacksonville, FL at 12:00Z on 1999-04-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 2 square meters per square second.1939Sfc1 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
746 J/kg
Mixed-layer CIN
-55 J/kg
Mixed-layer LCL
965 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
2 m²/s²
0-3 km storm-relative helicity
2 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.

NWS Jacksonville, FL wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 28, 3:35 PM EDT, 1 hour 9 minutes earlier.

Area forecast discussion, Apr 28, 3:35 PM EDT, 1 hour 9 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.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

In the hours before

Special weather statement, Apr 28, 11:15 AM EDT, 5 hours 29 minutes before
AMZ435-450-452-454-470-472-474-FLZ020>025-030>033-035>038-040-
GAZ132>136-149>154-162>166-282300-

SOUTHEAST GEORGIA AND NORTHEAST FLORIDA HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSONVILLE FL
1115 AM EDT WED APR 28 1999

SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP
ACROSS THE AREA THIS AFTERNOON AND INTO THE EVENING ACROSS
SOUTHEAST GEORGIA AND NORTHEAST FLORIDA.

EXPECT FREQUENT CLOUD TO GROUND LIGHTNING...SMALL HAIL...BRIEF
HEAVY RAINFALL...AND GUSTY WINDS IN THE STRONGER THUNDERSTORMS.
RAINFALL RATES WILL BE NEAR A QUARTER OF AN INCH BUT UP TO ONE
INCH IN A FEW AREAS.

SKYWARN STORM SPOTTER ACTIVATION WILL NOT BE NECESSARY.

FOR ADDITIONAL INFORMATION...LISTEN TO NOAA WEATHER RADIO OR VISIT
THE NATIONAL WEATHER SERVICE JACKSONVILLE WEBSITE ON THE INTERNET
AT HTTP://WWW.NWSJAX.NOAA.GOV (LOWER CASE).

SHASHY
Special weather statement, Apr 28, 11:15 AM EDT, 5 hours 29 minutes before
AMZ435-450-452-454-470-472-474-FLZ020>025-030>033-035>038-040-
GAZ132>136-149>154-162>166-282300-

SOUTHEAST GEORGIA AND NORTHEAST FLORIDA HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSONVILLE FL
1115 AM EDT WED APR 28 1999

SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP
ACROSS THE AREA THIS AFTERNOON AND INTO THE EVENING ACROSS
SOUTHEAST GEORGIA AND NORTHEAST FLORIDA.

EXPECT FREQUENT CLOUD TO GROUND LIGHTNING...SMALL HAIL...BRIEF
HEAVY RAINFALL...AND GUSTY WINDS IN THE STRONGER THUNDERSTORMS.
RAINFALL RATES WILL BE NEAR A QUARTER OF AN INCH BUT UP TO ONE
INCH IN A FEW AREAS.

SKYWARN STORM SPOTTER ACTIVATION WILL NOT BE NECESSARY.

FOR ADDITIONAL INFORMATION...LISTEN TO NOAA WEATHER RADIO OR VISIT
THE NATIONAL WEATHER SERVICE JACKSONVILLE WEBSITE ON THE INTERNET
AT HTTP://WWW.NWSJAX.NOAA.GOV (LOWER CASE).

SHASHY

The office that day

Everything else NWS Jacksonville, FL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 28, 2:15 PM EDTSevere Thunderstorm WarningJAXClay, Saint Johns50 min
Apr 28, 2:19 PM EDTSevere Thunderstorm WarningJAXAlachua, Bradford, Columbia, Union61 min
Apr 28, 2:49 PM EDTTornado WarningJAXAlachua46 min
Apr 28, 3:20 PM EDTSevere Thunderstorm WarningJAXFlagler, Saint Johns60 min

Nearby

Severe Thunderstorm Warnings in Florida, 1999Every 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; radar from the NEXRAD Level II archive.