Alert archive / Florida / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 16, NWS Melbourne, FL

April 28, 1999Orange County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at Apr 28, 1999, 2:44 PM EDT for Orange County, Florida. It was in force for 46 min. 2 reports 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, 2:44 PM EDT (18:44 UTC)
Expired
Apr 28, 1999, 3:30 PM EDT
In force
46 min
Issued by
NWS Melbourne, FL
Area
Whole counties

County Orange County, FL

The radar

The Melbourne radar (KMLB), 79 km from the middle of the area, began a volume at 18:44 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, 3:00 PM EDTHail 1Windermere, FL
Apr 28, 3:20 PM EDTHail 1Orlando, 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, 6.7 hours before the alert went out and 139 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, Tampa Bay, FL at 12:00Z on 1999-04-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1203 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, Tampa Bay, FL at 12:00Z on 1999-04-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 0 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
1203 J/kg
Mixed-layer CIN
-41 J/kg
Mixed-layer LCL
869 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
0 m²/s²
0-3 km storm-relative helicity
12 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

999 
WUUS01 KMLB 281842
SVRMLB
FLC095-281930-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MELBOURNE FL
244 PM EDT WED APR 28 1999

THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
     ORANGE COUNTY IN EAST CENTRAL FLORIDA

* UNTIL 330 PM EDT

* AT 345 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER THE GERATER ORLANDO AREA.  MOVEMENT WAS
  EAST AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
    WINDERMER AT 3 PM AND ORLANDO BY 315 PM


THIS IS A DANGEROUS STORM. BE PREPARED FOR DAMAGING WIND IN EXCESS
OF 58 MPH...LARGE HAIL AND DEADLY LIGHTNING. PEOPLE OUTSIDE OR IN
MOBILE HOMES SHOULD MOVE INSIDE A STRONG BUILDING AND STAY AWAY FROM
WINDOWS.

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 28, 10:30 AM EDT, 4 hours 14 minutes earlier.

Area forecast discussion, Apr 28, 10:30 AM EDT, 4 hours 14 minutes before
EAST CENTRAL FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
1030 AM EDT WED APR 28 1999

SQUALL LINE EXTENDING FROM LAKE OKEE NE INTO COASTAL WATERS SHOWING
SIGNS OF WEAKENING.  STRONG OUTFLOW BOUNDARY FROM COLLAPSING TSTMS
MOVING NORTH UP THE PENINSULA WILL HELP ENHANCE LOW LVL CONV WITH
THE WCSB FROM BREVARD NORTHWARD.  DEW POINTS IN THE MID 60S TO LOW
70S...AND DECENT INSTABILITY PARAMETERS.  COORD WITH KTPA...WILL
INCREASE POPS OVER NRN CWA.  MAY LOWER POPS OVER SRN CWA DUE TO CI
SHIELD AND THE RAIN COOLED AIR.

MARINE...NO CHANGES ATTM.

.MLB...NONE.

BRAGAW/CRISTALDI

In the hours before

Special weather statement, Apr 28, 11:25 AM EDT, 3 hours 19 minutes before
AMZ550-555-FLZ041-044>047-053-054-058-059-064-281725-

EAST CENTRAL FLORIDA HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MELBOURNE FL
1125 AM EDT WED APR 28 1999

...A FEW SEVERE THUNDERSTORMS POSSIBLE THIS AFTERNOON AND EVENING...

SUFFICIENT MOISTURE WILL COMBINE WITH A MODERATELY UNSTABLE
ATMOSPHERE AND SEA BREEZES TO PRODUCE SOME MUCH NEEDED RAIN THIS
AFTERNOON AND EVENING. RAINFALL COVERAGE IS EXPECTED TO BE A LITTLE
HIGHER THAN ON TUESDAY...WITH THE GREATEST CHANCES OVER THE COASTAL
COUNTIES DURING THE AFTERNOON.

A CLUSTER OF LIGHTNING STORMS BETWEEN LAKE OKEECHOBEE AND THE
MELBOURNE ORLANDO AREA WILL CONTINUE TO DRIFT TO THE EAST. A WELL
DEVELOPED SEA BREEZE FROM THE FLORIDA WEST COAST WILL MOVE EAST
INTO CENTRAL FLORIDA. ADDITIONAL LIGHTNING STORM DEVELOPMENT IS
EXPECTED OVER MUCH OF CENTRAL FLORIDA AS THIS SEA BREEZE
COLLIDES WITH THE OUTFLOW BOUNDARY MOVING NORTH FROM THE SOUTHERN
STORMS.  THE GREATEST THREAT FOR LIGHTNING STORMS AND
POSSIBLY LARGE HAIL AND DAMAGING WINDS WILL EXTEND FROM THE
GREATER ORLANDO AREA TO THE COAST AND AS FAR NORTH AS DAYTONA
BEACH.

MOST LIGHTNING FATALITIES AND INJURIES OCCUR IN OPEN FIELDS OR UNDER
TREES. IF OUTDOORS...SEEK SHELTER IN A STURDY BUILDING OR CAR. DO NOT
TAKE SHELTER IN SMALL SHEDS...UNDER ISOLATED TREES...OR IN
CONVERTIBLE AUTOMOBILES.

MARINE OUTLOOK...SCATTERED  STORMS WILL PRODUCE CLOUD TO GROUND
LIGHTNING NEAR OR EAST OF THE INTRACOASTAL WATERWAYS AS THE
INLAND LIGHTNING STORMS MOVE EAST THIS AFTERNOON. THESE STORMS WILL
LAST INTO THE EARLY EVENING.

DECKER

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 28, 1:48 PM EDTSevere Thunderstorm WarningMLBOrange42 min
Apr 28, 4:39 PM EDTSevere Thunderstorm WarningMLBVolusia61 min
Apr 28, 4:45 PM EDTSevere Thunderstorm WarningMLBLake60 min
Apr 28, 7:02 PM EDTTornado WarningMLBOsceola33 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.