Alert archive / Florida / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 98, NWS Melbourne, FL

July 11, 1999Volusia County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at Jul 11, 1999, 4:46 PM EDT for Volusia County, Florida. It was in force for 49 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 11, 1999, 4:46 PM EDT (20:46 UTC)
Expired
Jul 11, 1999, 5:35 PM EDT
In force
49 min
Issued by
NWS Melbourne, FL
Area
Whole counties

County Volusia County, FL

The radar

The Melbourne radar (KMLB), 116 km from the middle of the area, began a volume at 20:45 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.

The nearest sounding before it

Jacksonville, FL (KJAX), launched 12:00Z, 8.8 hours before the alert went out and 168 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 1999-07-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 215 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 1999-07-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -1 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
215 J/kg
Mixed-layer CIN
-109 J/kg
Mixed-layer LCL
1307 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
-1 m²/s²
0-3 km storm-relative helicity
-11 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.

483 
WUUS01 KMLB 112048
SVRMLB
FLC127-112135-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MELBOURNE FL
446 PM EDT SUN JUL 11 1999

THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED A

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

* UNTIL 535 PM EDT

* AT 443 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 5 MILES NORTHEAST OF DE LAND.  MOVEMENT WAS
  SOUTH AT 10 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
    WILL MOVE TO JUST EAST OF LAKE HELEN BY 5 PM
    AND TO NEAR OSTEEN BY 520 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.

$$

TROUTMAN/WIMMER

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 Jul 11, 2:45 PM EDT, 2 hours 1 minute earlier.

Area forecast discussion, Jul 11, 2:45 PM EDT, 2 hours 1 minute before
EAST CENTRAL FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
245 PM EDT SUN JUL 11 1999

SURFACE HEATING HAS PLAYED A BIG PART IN THE TWO DIFFERENT AREAS
WHERE STORM DEVELOPMENT WAS OCCURRING. THE SPC OUTLOOKED AREA OVER N
CENTRAL FL WAS MAIN AREA OF INTEREST AS A TRAILING VORT LOBE OVER N
CENTRAL FL AND A MESOSCALE SURFACE BOUNDARY ALONG WITH THE WEST
COAST SEA BREEZE HAS ALLOWED FOR A FEW STRONG STORMS TO FORM DURING
THE LAST COUPLE OF HOURS. THIS ACTIVITY WILL BE STEERED SLOWLY EAST
TO THE COAST.

TONIGHT...DIURNAL STORMS TO END WITH DUSK. WEAK SUBSIDENCE IS
INDICATED ALOFT IN THE WAKE OF THE AFOREMENTIONED VORT LOBE. THE
RIDGE AXIS REMAINS IN PLACE AT SFC ACROSS CENTRAL FL ALLOWING WINDS
TO DROP TO CALM UNDER PARTLY CLOUDY SKIES.

MONDAY-TUESDAY NIGHT...AXIS OF BROAD DEEP LAYER RIDGE WILL DROP SLOWLY
FROM NORTHERN PORTION OF CWA TO SOUTHERN SECTIONS AS A WEAK SURFACE
TROUGH REACHES THE SE STATES. DEPTH OF MOIST LAYER WILL GRADUALLY
INCREASE OVER CENTRAL FLORIDA...RETURNING DIURNAL CONVECTIVE
COVERAGES BACK TO NEAR NORMAL FOR MID JULY. SURFACE FLOW SHOULD
REMAIN LIGHT ENOUGH FOR AFTERNOON SEA BREEZES...ESTABLISHING
EARLIEST/STRONGEST SOUTH OF THE CAPE. RIDGE AXIS WILL DIVIDE THE CWA
NEXT TWO AFTERNOONS WITH STORMS OVER S HALF MOVING INLAND DURING THE
AFTERNOON...AND ACTIVITY TO THE NORTH FAVORING THE ATLANTIC COAST BY
LATE DAY. ACTIVITY WILL LINGER INTO THE EVENINGS...MAINLY
NORTH/CENTRAL AREAS WHERE W STEERING FLOW PREVAILS. MAX TEMPS
GENERALLY A CATEGORY ABOVE NORMAL ALONG COAST THROUGH EARLY/MID
AFTERNOON...PRIOR TO SEA BREEZE ONSET.

WEDNESDAY-FRIDAY...AS AXIS OF BROAD RIDGE SHIFTS SLOWLY BACK TO THE
NORTH...DEEPENING SE FLOW BECOMES RE-ESTABLISHED ACROSS THE CWA. MAY
BE ENOUGH SOUTHERLY STEERING COMPONENT INITIALLY TO HOLD SOME
CONVECTION CLOSE TO THE EAST COAST...HOWEVER TIMING OF ACTIVITY
SHOULD FAVOR MORNINGS NEAR THE COAST AND AFTERNOONS OVER THE
INTERIOR BY LATE WEEK. DO NOT FORESEE ANY GREATLY ENHANCED MOISTURE
SOURCES UPSTREAM...THUS WILL MAINTAIN NEAR CLIMO POPS FOR THE
EXTENDED PERIOD. TEMPS ALSO NEAR NORMAL.

MARINE...NO HIGHLIGHTS. LIGHT FLOW WILL GIVE WAY TO AFTERNOON SEA
BREEZES NEAR SHORE. SCATTERED STORMS WILL MOVE OFFSHORE THE
PENINSULA LATE AFTERNOON THROUGH EARLY EVENING...ESPECIALLY N OF VRB.

DAB BB 073/092 073/092 073 65243
MCO BB 073/093 073/092 073 65243
MLB BB 075/091 074/091 073 65133

.MLB...NONE.

PENDERGRAST/SPRATT

In the hours before

Special weather statement, Jul 11, 2:08 PM EDT, 2 hours 38 minutes before
AMZ550-555-570-575-FLZ041-044>047-053-054-058-059-064-112000-

EAST CENTRAL FLORIDA HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE MELBOURNE FL
208 PM EDT SUN JUL 11 1999

...A FEW STRONG TO POSSIBLY SEVERE LIGHTNING STORMS POSSIBLE THIS
AFTERNOON...

THE COMBINATION OF SURFACE MOISTURE AND HEATING ALONG WITH DRY AIR
AT MID LEVELS OF THE ATMOSPHERE WILL ALLOW FOR THE FORMATION OF A
FEW STRONG LIGHTNING STORMS MAINLY OVER LAKE...VOLUSIA ...SEMINOLE
AND ORANGE COUNTY THROUGH 6 PM. THE MAIN THREAT FROM THE STRONGER
ST0RMS THAT DEVELOP WILL BE WIND GUSTS TO 45 MPH ALONG WITH SMALL
HAIL AND DANGEROUS LIGHTNING. MOVEMENT WILL BE EAST AT 10 MPH AND
THE STORMS WILL AFFECT TEH BEACHES OF VOLUSIA COUNTY TO FLAGLER
BEACH LATER THIS AFTERNOON. ELSEWHERE...CONSIDERABLE CLOUDS OVER
BREVARD...OSCEOLA AND INDIAN RIVER COUNTY WILL LIMIT THE COVERAGE OF
STORMS AND THEY SHOULD REMAIN BELOW SEVERE LIMITS. OVER ST LUCIE...
MARTIN AND OKEECHOBEE COUNTIES SCATTERED LIGHTNING STORMS WILL
AFFECT THE COASTAL AREAS AS THE ATLANTIC SEABREEZE MOVES
INLAND.

ALL STORMS WILL BE CAPABLE OF DEADLY LIGHTNING. MOVE INDOORS AT THE
FIRST SIGN OF THREATENING SKIES...AND MAKE SURE LIGHTNING IS WELL
AWAY FROM YOUR LOCATION BEFORE RESUMING OUTDOOR ACTIVITIES.

PENDERGRAST
Special weather statement, Jul 11, 2:08 PM EDT, 2 hours 38 minutes before
AMZ550-555-570-575-FLZ041-044>047-053-054-058-059-064-112000-

EAST CENTRAL FLORIDA HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE MELBOURNE FL
208 PM EDT SUN JUL 11 1999

...A FEW STRONG TO POSSIBLY SEVERE LIGHTNING STORMS POSSIBLE THIS
AFTERNOON...

THE COMBINATION OF SURFACE MOISTURE AND HEATING ALONG WITH DRY AIR
AT MID LEVELS OF THE ATMOSPHERE WILL ALLOW FOR THE FORMATION OF A
FEW STRONG LIGHTNING STORMS MAINLY OVER LAKE...VOLUSIA ...SEMINOLE
AND ORANGE COUNTY THROUGH 6 PM. THE MAIN THREAT FROM THE STRONGER
ST0RMS THAT DEVELOP WILL BE WIND GUSTS TO 45 MPH ALONG WITH SMALL
HAIL AND DANGEROUS LIGHTNING. MOVEMENT WILL BE EAST AT 10 MPH AND
THE STORMS WILL AFFECT TEH BEACHES OF VOLUSIA COUNTY TO FLAGLER
BEACH LATER THIS AFTERNOON. ELSEWHERE...CONSIDERABLE CLOUDS OVER
BREVARD...OSCEOLA AND INDIAN RIVER COUNTY WILL LIMIT THE COVERAGE OF
STORMS AND THEY SHOULD REMAIN BELOW SEVERE LIMITS. OVER ST LUCIE...
MARTIN AND OKEECHOBEE COUNTIES SCATTERED LIGHTNING STORMS WILL
AFFECT THE COASTAL AREAS AS THE ATLANTIC SEABREEZE MOVES
INLAND.

ALL STORMS WILL BE CAPABLE OF DEADLY LIGHTNING. MOVE INDOORS AT THE
FIRST SIGN OF THREATENING SKIES...AND MAKE SURE LIGHTNING IS WELL
AWAY FROM YOUR LOCATION BEFORE RESUMING OUTDOOR ACTIVITIES.

PENDERGRAST

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.