Alert archive / Florida / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 10, NWS Melbourne, FL

April 27, 1999Martin County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at Apr 27, 1999, 4:23 PM EDT for Martin County, Florida. It was in force for 47 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 27, 1999, 4:23 PM EDT (20:23 UTC)
Expired: Apr 27, 1999, 5:10 PM EDT
In force: 47 min
Issued by: NWS Melbourne, FL
Area: Whole counties

County Martin County, FL

The radar

The Melbourne radar (KMLB), 117 km from the middle of the area, began a volume at 20:24 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

Time	Report	Where	Remark
Apr 27, 4:55 PM EDT	Hail 0.75	Stuart, FL

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

Tampa Bay, FL (KTBW), launched 12:00Z, 8.4 hours before the alert went out and 210 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: 684 J/kg
Mixed-layer CIN: -39 J/kg
Mixed-layer LCL: 913 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 16 m²/s²
0-3 km storm-relative helicity: 20 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

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 Melbourne, FL wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 27, 3:30 PM EDT, 53 minutes earlier.

Area forecast discussion, Apr 27, 3:30 PM EDT, 53 minutes before

EAST CENTRAL FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
330 PM EDT TUE APR 27 1999

CURRENTLY...STRONG CONVECTION FIRING OVER S FL PEN...WEAKER RW TO
THE NORTH MOVING INTO WRN CWA.  ECSB HAS DEVELOPED AS EXPECTED...AND
IS MAKING SLOW PROGRESS INLAND.  PLENTY OF TSTM FUEL AS DEWPOINTS
ARE IN THE 60S AND LOW 70S.  FURTHERMORE...SRN CONVECTION IS NOT
CHOKING OFF THE LOW LEVEL FLOW TO THE NRN CONVECTION...SO EXPECT THE
LATTER TO ENCOUNTER THE ECSB SHORTLY.

TONIGHT/WED...LOW/MID LEVEL CLOSED LOW OVER THE MIDWEST WILL SAG SE
UNDER THE INFLUENCE OF A DEVELOPING MID/UPR LVL RIDGE OVER THE
PLAINS AND HELP ERODE THE SUBTROPICAL RIDGE OVER THE PEN.  EXPECT SW
FLOW AND ABV NORMAL TEMPS TO CONTINUE INTO WED NIGHT AS THE MIDWEST
CLOSED LOW BECOMES ABSORBED INTO THE CLOSED LOW OVER THE GEORGES
BANKS.  UNDER THE CONTINUED S-SW LOW LVL FLOW...CAN ONLY EXPECT PW
VALUES TO REMAIN AOA CURRENT LEVELS THROUGH 00Z THU.  HOWEVER...H50
VORT AND H25 JET DYNAMICS MARGINAL...SO SCT POPS THE BEST BET.
SIMILAR WX PATTERN TOMORROW...WITH DIURNAL HEATING RESULTING IN THE
WCSB MAKING ITS WAY WELL INTO THE PEN... AND ECSB REMAINING NEAR
SHORE. BETTER CHANCE FOR SOME LATE NIGHT FOG INLAND AS THERE SHOULD
BE A LITTLE MORE CONVECTION OVER THE CWA.

.THU AND BEYOND...COORD WITH NCEP W/R/T THE MED RANGE AND THINKING
IS THAT THE SURFACE LOW AND WIND FIELDS ARE TOO STRONG. EXPECT A
WEAKER SURFACE WAVE TO DEVELOP AND A BIT FARTHE EAST. SCT POPS STILL
EXPECTED UNTIL FRONT CLEARS AREA ON FRIDAY. HAVE LEFT SAT/SUN DRY
FOR NOW...UNTIL I GET A BETTER FEEL FOR FRONTAL POSN BY THE WEEKEND.

.MLB...NONE.

CCF NUMBERS WILL FOLLOW IN A BIT...

BRAGAW/CRISTALDI

In the hours before

Special weather statement, Apr 27, 11:50 AM EDT, 4 hours 33 minutes before

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Special weather statement, Apr 27, 11:50 AM EDT, 4 hours 33 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 Melbourne, FL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 27, 5:15 PM EDT	Severe Thunderstorm Warning	MLB	Okeechobee	45 min
Apr 27, 5:46 PM EDT	Severe Thunderstorm Warning	MLB	Indian River	34 min
Apr 27, 6:39 PM EDT	Severe Thunderstorm Warning	MLB	Brevard	41 min
Apr 27, 6:52 PM EDT	Severe Thunderstorm Warning	MLB	Osceola	43 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.