Alert archive / Florida / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 87, NWS Melbourne, FL

June 4, 1999Lake County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at Jun 4, 1999, 4:47 PM EDT for Lake County, Florida. It was in force for 48 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
Jun 4, 1999, 4:47 PM EDT (20:47 UTC)
Expired
Jun 4, 1999, 5:35 PM EDT
In force
48 min
Issued by
NWS Melbourne, FL
Area
Whole counties

County Lake County, FL

The radar

The Melbourne radar (KMLB), 126 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
Jun 4, 5:05 PM EDTHail 0.75Leesburg, FL
Jun 4, 5:05 PM EDTHail 0.75Leesburg, 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

Jacksonville, FL (KJAX), launched 12:00Z, 8.8 hours before the alert went out and 193 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 1999-06-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 640 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 1999-06-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 110 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
640 J/kg
Mixed-layer CIN
-97 J/kg
Mixed-layer LCL
1110 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
110 m²/s²
0-3 km storm-relative helicity
104 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 042048
SVRMLB
FLC069-042135-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MELBOURNE FL
447 PM EDT FRI JUN 4 1999

THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED A

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

* UNTIL 535 PM EDT

* AT 447 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM NEAR TAVARES..  MOVEMENT WAS SOUTH AT 10 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
    HOWEY IN THE HILLS BY 510 PM AND GROVELAND BY 525 PM

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 58
MPH...DESTRUCTIVE HAIL...DEADLY LIGHTNING AND VERY HEAVY RAIN.
MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A STRONG BUILDING.

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 Jun 4, 3:40 PM EDT, 1 hour 7 minutes earlier.

Area forecast discussion, Jun 4, 3:40 PM EDT, 1 hour 7 minutes before
EAST CENTRAL FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
340 PM EDT FRI JUN 4 1999

CURRENTLY...CONVECTION FIRING ALONG AND AHEAD OF SEA BREEZE WHICH
GOT A BIT OF A LATE START TODAY. AS A RESULT...SHOWERS AND STORMS
ARE CLOSER TO THE COAST THAN ANTICIPATED. 15Z CAP SOUNDING SHOWS
SOME MOISTENING HAS OCCURRED SINCE 10Z...WITH PWAT OF 1.59 INCHES.
ALOFT...MODERATELY UNSTABLE LAPSE RATES WITH H5 TEMP NEAR -9C AS
VORT MIN DROPS DOWN THE PENINSULA. APPEARS SUBSIDENCE IN WAKE OF
ANTICYCLONIC VORT LOBE IS DONE.

TONIGHT...EXPECT COLLISION OF SEA BREEZES TO OCCUR OVER INTERIOR
SECTIONS THIS EVENING WHICH SHOULD PRODUCE SOME ADDITIONAL STRONG TO
POTENTIALLY SEVERE THUNDERSTORM CELLS...WITH COUNTIES SURROUNDING
METRO ORLANDO BEING MOST VULNERABLE ONCE AGAIN IN OUR FA. MODELS
AGREE ON  BRINGING IN NEXT SHORTWAVE AND ASSOCIATED PVA INTO NORTH
FL THIS EVENING. WILL INTRODUCE CHANCE POPS FOR INTERIOR COUNTIES
THIS EVENING TO ACCOUNT FOR CURRENT ACTIVITY...AND WILL LET SWING
SHIFT DECIDE IF THEY NEED TO BE IN OVERNIGHT. BOUNDARY LAYER FLOW
DOES NOT PICK UP UNTIL LATE TOMORROW...SO WILL PUT OFF MENTION OF
COASTAL SHOWERS UNTIL TOMORROW NIGHT.

SAT...HAVE ESSENTIALLY RULED OUT AVN SCENARIO THIS CYCLE DUE TO LACK
OF BELIEVABILITY OF A TIGHT SURFACE LOW SPINNING UP SE OF FLORIDA.
HOWEVER...EASTERLY GRADIENT WILL PICK UP DURING THE DAY DUE TO HIGH
PRES BUILDING OVER THE W ATLC...ALLOWING FASTER INLAND PENETRATION
OF SEA BREEZE. STILL PLENTY OF MOISTURE AVAILABLE AS MODEL PWATS 1.5
TO 1.7". AS SUCH HAVE OPTED FOR SLIGHT CHC TO CHC POPS INLAND. WILL
ADD A SLIGHT CHANCE FOR LATE NIGHT COASTA SHRA AS MEAN SFC-850 FLOW
CONTINUES TO INCREASE.

SUN AND BEYOND...BREEZY TO WINDY CONDTIONS AREAWIDE AS WHAT I EXPECT
TO BE AN INVERTED TROUGH NEARS 77-78W COUPLED WITH PSBLTY OF ATLC
SURFACE HIGH WEDGING A LITTLE BIT DOWN INTO THE CAROLINAS/N GEORGIA
(INDICATED BY ETA). ETA/NGM DIFFER IN THE AMOUNT OF MOISTURE OVER
THE PENINSULA WITH NGM A COUPLE TENTHS DRIER AT 12Z SUN. BOTH MODELS
SHOW GENEROUS SLUG OF MOISTURE POISED TO SURGE ACROSS BOTH SOUTH/
CENTRAL FLORIDA...HOWEVER OVERALL STRENGTH/AMPLITUDE OF THIS FEATURE
REMAINS IN QUESTION. THIS SPEAKS TO HOW FAR NORTH DEEPER MOISTURE
WILL BE DRAWN. ALTHOUGH I'M STILL TAKING A CONSERVATIVE APPROACH
WITH THIS FEATURE SUN...I EVENTUALLY EXPECT ALL AREAS TO HAVE A
BETTER THAN CLIMO CHANCE FOR DIURNAL AFTERNOON STORMS ON THE BACK
SIDE OF THIS FEATURE...ESP IF IT MOVES MORE WNW THAN W AFTER DAY 3
(A LA THE EURO MODELS).

MARINE...WINDS/SEAS TO INCREASE STEADILY THROUGH THE WEEKEND...BUT
HIGHLIGHTS WILL LIKELY WAIT UNTIL SUN AT THE EARLIEST.

DAB BB 070/086 074/084 074 60-32
MCO BB 071/090 072/088 073 60332
MLB BB 071/087 075/085 076 60022=

.MLB...NONE.

KELLY/CRISTALDI

In the hours before

Special weather statement, Jun 4, 11:35 AM EDT, 5 hours 12 minutes before
AMZ550-555-570-575-FLZ041-044>047-053-054-058-059-064-042200-

EAST CENTRAL FLORIDA HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MELBOURNE FL
1135 AM EDT FRI JUN 4 1999

...WIDELY SCATTERED LIGHTNING STORMS EXPECTED THIS AFTERNOON...

LIGHT WINDS WILL ALLOW THE ATLANTIC SEA BREEZE TO FORM AROUND NOON
SOUTH OF CAPE CANAVERAL...AND BY 2 PM NORTH OF CAPE CANAVERAL. AS
THE SEA BREEZE BOUNDARY MOVES INLAND...IT WILL COMBINE WITH
SUFFICIENT MOISTURE TO ACT AS A FOCUS FOR SCATTERED SHOWER AND
LIGHTNING STORM FORMATION. THROUGH MID AFTERNOON...A FEW STORMS WILL
BEGIN TO FORM OVER THE COASTAL COUNTIES...ESPECIALLY INLAND SAINT
LUCIE AND MARTIN COUNTIES...WHERE LAKE AND SEA BREEZES WILL
INTERACT. STORM DEVELOPMENT WILL SHIFT INLAND AND INCREASE IN
COVERAGE LATE THIS AFTERNOON AND EVENING OVER THE CENTRAL FLORIDA
INTERIOR. STORM MOVEMENT IS EXPECTED TO BE SOUTH AT 10 TO 15 MPH.

ISOLATED STORMS COULD BECOME STRONG AND PRODUCE SMALL HAIL AND WIND
GUSTS TO AROUND 40 MPH. DEADLY CLOUD TO GROUND LIGHTNING AND BRIEF
HEAVY RAIN WILL ALSO ACCOMPANY THE STORMS. DONT TAKE CHANCES WHEN
LIGHTNING STORMS ARE NEARBY...MOVE QUICKLY TO A SAFE LOCATION
INDOORS.

AS STORMS BEGIN TO FORM ALONG THE SEA BREEZE EARLY THIS AFTERNOON...
CLOUD TO WATER LIGHTNING MAY AFFECT A FEW AREAS ALONG THE
INTRACOASTAL WATERWAYS AND NEARSHORE ATLANTIC WATERS. THE MOST
FAVORED COASTAL AREAS FOR LIGHTNING TODAY WILL BE NEAR MERRITT ISLAND
AND SOUTH OF FORT PIERCE INLET.

KELLY
Special weather statement, Jun 4, 11:35 AM EDT, 5 hours 12 minutes before
AMZ550-555-570-575-FLZ041-044>047-053-054-058-059-064-042200-

EAST CENTRAL FLORIDA HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MELBOURNE FL
1135 AM EDT FRI JUN 4 1999

...WIDELY SCATTERED LIGHTNING STORMS EXPECTED THIS AFTERNOON...

LIGHT WINDS WILL ALLOW THE ATLANTIC SEA BREEZE TO FORM AROUND NOON
SOUTH OF CAPE CANAVERAL...AND BY 2 PM NORTH OF CAPE CANAVERAL. AS
THE SEA BREEZE BOUNDARY MOVES INLAND...IT WILL COMBINE WITH
SUFFICIENT MOISTURE TO ACT AS A FOCUS FOR SCATTERED SHOWER AND
LIGHTNING STORM FORMATION. THROUGH MID AFTERNOON...A FEW STORMS WILL
BEGIN TO FORM OVER THE COASTAL COUNTIES...ESPECIALLY INLAND SAINT
LUCIE AND MARTIN COUNTIES...WHERE LAKE AND SEA BREEZES WILL
INTERACT. STORM DEVELOPMENT WILL SHIFT INLAND AND INCREASE IN
COVERAGE LATE THIS AFTERNOON AND EVENING OVER THE CENTRAL FLORIDA
INTERIOR. STORM MOVEMENT IS EXPECTED TO BE SOUTH AT 10 TO 15 MPH.

ISOLATED STORMS COULD BECOME STRONG AND PRODUCE SMALL HAIL AND WIND
GUSTS TO AROUND 40 MPH. DEADLY CLOUD TO GROUND LIGHTNING AND BRIEF
HEAVY RAIN WILL ALSO ACCOMPANY THE STORMS. DONT TAKE CHANCES WHEN
LIGHTNING STORMS ARE NEARBY...MOVE QUICKLY TO A SAFE LOCATION
INDOORS.

AS STORMS BEGIN TO FORM ALONG THE SEA BREEZE EARLY THIS AFTERNOON...
CLOUD TO WATER LIGHTNING MAY AFFECT A FEW AREAS ALONG THE
INTRACOASTAL WATERWAYS AND NEARSHORE ATLANTIC WATERS. THE MOST
FAVORED COASTAL AREAS FOR LIGHTNING TODAY WILL BE NEAR MERRITT ISLAND
AND SOUTH OF FORT PIERCE INLET.

KELLY
Local storm report, Jun 4, 4:31 PM EDT, 16 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MELBOURNE FL
431 PM EDT FRI JUN 04 1999

TIME(EDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0345 PM    ORLANDO                   FL   WIND DAMAGE
06/04/99   ORANGE                         A LOCAL RADIO STATION
                                          REPORTED THREE TREES DOWN
                                          AT THE CORNER OF CHURCH
                                          STREET AND ORANGE AVENUE
                                          IN ORLANDO.

TROUTMAN

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 3, 8:10 PM EDTSevere Thunderstorm WarningMLBLake45 min
Jun 3, 8:54 PM EDTSevere Thunderstorm WarningMLBLake36 min
Jun 4, 3:01 PM EDTSevere Thunderstorm WarningMLBSeminole, Volusia44 min
Jun 4, 3:36 PM EDTSevere Thunderstorm WarningMLBOrange44 min
Jun 4, 4:26 PM EDTSevere Thunderstorm WarningMLBOsceola44 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.