Alert archive / Florida / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 48, NWS Melbourne, FL

May 9, 1999Martin County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at May 9, 1999, 2:30 PM EDT for Martin County, Florida. It was in force for 45 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
May 9, 1999, 2:30 PM EDT (18:30 UTC)
Expired
May 9, 1999, 3:15 PM EDT
In force
45 min
Issued by
NWS Melbourne, FL
Area
Whole counties

County Martin County, FL

What was reported inside it

TimeReportWhereRemark
May 9, 2:52 PM EDTHail 0.75Palm City, FL
May 9, 2:55 PM EDTHail 0.75Indiantown, 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
May 9, 2:00 PM EDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Miami, FL (KMFL), launched 12:00Z, 6.5 hours before the alert went out and 141 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, Miami, FL at 12:00Z on 1999-05-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1797 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, Miami, FL at 12:00Z on 1999-05-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -33 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
1797 J/kg
Mixed-layer CIN
-27 J/kg
Mixed-layer LCL
812 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
-33 m²/s²
0-3 km storm-relative helicity
-18 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.

000 
TTAA00 KMLB 091830 RRA
SVRMLB
FLC085-091915-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MELBOURNE FL
230 PM EDT SUN MAY 9 1999

THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...

     MARTIN COUNTY IN EAST CENTRAL FLORIDA

* UNTIL 315 PM EDT

* AT 225 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  CLUSTER OF SEVERE THUNDERSTORMS FROM THE PALM BEACH/MARTIN
  COUNTY LINE WEST OF JUPITER TO NEAR INDIANTOWN. ANOTHER STRONG
  STORM WAS DEVELOPING NEAR PALM CITY.   MOVEMENT OF THE STORMS WAS
  NEARLY STATIONARY.

* THE STORMS WILL AFFECT CENTRAL AND EASTERN MARTIN COUNTY WITH
  LARGE HAIL...GUSTY WINDS AND FREQUENT LIGHTNING.

THESE ARE DANGEROUS STORMS. 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 May 9, 10:22 AM EDT, 4 hours 8 minutes earlier.

Area forecast discussion, May 9, 10:22 AM EDT, 4 hours 8 minutes before
EAST CENTRAL FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
1022 AM EDT SUN MAY 9 1999

MORN SOUNDINGS STILL SUFFICIENTLY MOIST AND UNSTABLE THROUGH C AND S
PART OF STATE WHILE DRIER AND MORE STABLE AIR OVER NRN FL. AREA OF
HIGH CLOUDS SPREADING OVER REGION BUT SHOULD BE ON THE WANE THROUGH
THE AFTN AS VORT PASSES ACROSS SRN PART OF STATE. WHILE STORM
COVERAGE MAY NOT BE TOO HIGH...THE STORMS THAT DO DEVELOP COULD GET
STRONG WITH HIGHER COVERAGE EXPECTED IN SRN SECTIONS THAN IN N.
WILL UPDATE ZONES TO FRESHEN WORDING AND MAKE MINOR TWEAKS.

MARINE...WEAK SURFACE PRESSURE GRADIENT WILL KEEP WINDS LESS THAN 15
KT WITH ONSHORE WINDS NEAR THE COAST DURING THE AFTERNOON. OFFSHORE
BUOYS REPORTING 1 FT WIND WAVES...2 FT SWELLS WITH A PERIOD OF 12
SECONDS OR MORE. NO SIGNIFICANT CHANGES TO CURRENT COASTAL WATERS
FORECAST.

.MLB...NONE.

GLITTO/WIMMER

In the hours before

Special weather statement, May 9, 11:24 AM EDT, 3 hours 6 minutes before
AMZ550-555-570-575-FLZ041-044>047-053-054-058-059-064-092000-

EAST CENTRAL FLORIDA HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MELBOURNE FL
1124 AM EDT SUN MAY 9 1999

...SCATTERED AFTERNOON AND EVENING LIGHTNING STORMS WITH A FEW
STRONG TO SEVERE STORMS POSSIBLE...

AFTERNOON HEATING COMBINED WITH AN UNSTABLE AIR MASS AND SEA BREEZE
BOUNDARIES WILL ALLOW SCATTERED LIGHTNING STORMS TO FORM AGAIN OVER
EAST CENTRAL FLORIDA. A FEW STORMS MAY BEGIN TO DEVELOP DURING THE
EARLY AFTERNOON...BUT THE HIGHEST COVERAGE OF STORMS IS EXPECTED TO
BE SOUTH OF CAPE CANAVERAL AND ORLANDO DURING THE LATE AFTERNOON AND
EARLY EVENING HOURS.

THE MAIN THREATS WITH STRONGER STORMS WILL BE FREQUENT LIGHTNING...
LARGE HAIL AND DAMAGING WIND GUSTS. DUE TO THE SLOW MOVEMENT OF SOME
STORMS...LOCALLY HEAVY RAIN WILL BE POSSIBLE...WHICH CAN CAUSE
PONDING OF WATER ON ROADS AND IN LOW LYING AREAS.

IF YOU PLAN TO BE OUTDOORS...BE PREPARED TO MOVE INDOORS AT THE
FIRST SIGN OF AN APPROACHING STORM. MARINE INTERESTS SHOULD SEEK HARBOR
BEFORE A STORM IS OVERHEAD. SKYWARN SPOTTER NETWORKS ARE REQUESTED
TO SELF ACTIVATE IF A WARNING IS ISSUED FOR THEIR COUNTY.

GLITTO
Special weather statement, May 9, 1:45 PM EDT, 45 minutes before
AMZ550-555-570-575-FLZ041-044>047-053-054-058-059-064-100000-

EAST CENTRAL FLORIDA HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MELBOURNE FL
145 PM EDT SUN MAY 9 1999

...SEVERE THUNDERSTORM WATCH UNTIL 800 PM FOR OSCEOLA...
OKEECHOBEE...BREVARD...INDIAN RIVER...ST LUCIE AND MARTIN COUNTIES...

AFTERNOON HEATING COMBINED WITH A VERY UNSTABLE AIR MASS AND SEA
BREEZE BOUNDARIES WILL CONTINUE THUNDERSTORM DEVELOPMENT THROUGH THE
AFTERNOON AND INTO THE EVENING HOURS. AS STORMS CONTINUE TO
INTENSIFY THIS AFTERNOON... SEVERE STORMS WILL BE POSSIBLE...
ESPECIALLY OVER AREAS SOUTH OF ORLANDO AND CAPE CANAVERAL.

THE MAIN THREATS FROM SEVERE STORMS WILL BE LARGE HAIL AND DAMAGING
WIND GUSTS. ADDITIONALLY...FREQUENT TO EXCESSIVE LIGHTNING AND VERY
HEAVY RAIN WILL BE POSSIBLE. RAINFALL AMOUNTS OF AROUND TWO INCHES
MAY OCCUR IN A SHORT PERIOD OF TIME...WHICH CAN CAUSE PONDING OF
WATER ON ROADS AND IN LOW LYING AREAS.

PERSONS SHOULD BE PREPARED TO GO TO A PLACE OF SAFETY IMMEDIATELY IF
A STORM APPROACHES. SKYWARN SPOTTER NETWORKS ARE REQUESTED TO SELF
ACTIVATE IF A WARNING IS ISSUED FOR THEIR COUNTY.

GLITTO
Special weather statement, May 9, 1:45 PM EDT, 45 minutes before
AMZ550-555-570-575-FLZ041-044>047-053-054-058-059-064-100000-

EAST CENTRAL FLORIDA HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MELBOURNE FL
145 PM EDT SUN MAY 9 1999

...SEVERE THUNDERSTORM WATCH UNTIL 800 PM FOR OSCEOLA...
OKEECHOBEE...BREVARD...INDIAN RIVER...ST LUCIE AND MARTIN COUNTIES...

AFTERNOON HEATING COMBINED WITH A VERY UNSTABLE AIR MASS AND SEA
BREEZE BOUNDARIES WILL CONTINUE THUNDERSTORM DEVELOPMENT THROUGH THE
AFTERNOON AND INTO THE EVENING HOURS. AS STORMS CONTINUE TO
INTENSIFY THIS AFTERNOON... SEVERE STORMS WILL BE POSSIBLE...
ESPECIALLY OVER AREAS SOUTH OF ORLANDO AND CAPE CANAVERAL.

THE MAIN THREATS FROM SEVERE STORMS WILL BE LARGE HAIL AND DAMAGING
WIND GUSTS. ADDITIONALLY...FREQUENT TO EXCESSIVE LIGHTNING AND VERY
HEAVY RAIN WILL BE POSSIBLE. RAINFALL AMOUNTS OF AROUND TWO INCHES
MAY OCCUR IN A SHORT PERIOD OF TIME...WHICH CAN CAUSE PONDING OF
WATER ON ROADS AND IN LOW LYING AREAS.

PERSONS SHOULD BE PREPARED TO GO TO A PLACE OF SAFETY IMMEDIATELY IF
A STORM APPROACHES. SKYWARN SPOTTER NETWORKS ARE REQUESTED TO SELF
ACTIVATE IF A WARNING IS ISSUED FOR THEIR COUNTY.

GLITTO

The office that day

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

IssuedProductOfficeCountiesLasted
May 8, 8:26 PM EDTSevere Thunderstorm WarningMLBSaint Lucie49 min
May 9, 2:59 PM EDTSevere Thunderstorm WarningMLBSaint Lucie61 min
May 9, 3:20 PM EDTSevere Thunderstorm WarningMLBBrevard60 min
May 9, 3:32 PM EDTSevere Thunderstorm WarningMLBIndian River63 min
May 9, 3:52 PM EDTSevere Thunderstorm WarningMLBOkeechobee58 min
May 9, 4:27 PM EDTSevere Thunderstorm WarningMLBBrevard48 min
May 9, 4:36 PM EDTSevere Thunderstorm WarningMLBVolusia64 min
May 9, 5:21 PM EDTSevere Thunderstorm WarningMLBBrevard29 min
May 9, 5:23 PM EDTSevere Thunderstorm WarningMLBSeminole47 min
May 9, 6:16 PM EDTSevere Thunderstorm WarningMLBOrange59 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.