Alert archive / Florida / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 96, NWS Melbourne, FL

July 9, 1999Volusia County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at Jul 9, 1999, 5:30 PM EDT for Volusia County, Florida. It was in force for 45 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: Jul 9, 1999, 5:30 PM EDT (21:30 UTC)
Expired: Jul 9, 1999, 6:15 PM EDT
In force: 45 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 21:30 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
Jul 9, 6:20 PM EDT	Thunderstorm Wind 50	Ormond Beach, FL	Thunderstorm winds blew down a few trees west of Ormond Beach.

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

Cape Canaveral, FL (KXMR), launched 12:00Z, 9.5 hours before the alert went out and 91 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: 2444 J/kg
Mixed-layer CIN: -27 J/kg
Mixed-layer LCL: 954 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: 5 m²/s²
0-3 km storm-relative helicity: -6 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.

418 
WUUS01 KMLB 092130 RRA
SVRMLB
FLC127-092215-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MELBOURNE FL
530 PM EDT FRI JUL 9 1999

THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED A

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

* UNTIL 615 PM EDT

* AT 529 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM JUST WEST OF DELAND.  MOVEMENT WAS NORTHEAST AT
  10 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
    JUST EAST OF DE LEON SPRINGS BY 540 PM AND DAYTONA BEACH BY 6 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

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 9, 2:55 PM EDT, 2 hours 35 minutes earlier.

Area forecast discussion, Jul 9, 2:55 PM EDT, 2 hours 35 minutes before

EAST CENTRAL FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
255 PM EDT FRI JUL 9 1999

STORM ACTIVITY INCREASING ALONG BOTH SEA BREEZE FRONTS ATTM.
INTERIOR COUNTIES WILL BE THE PRIME FOCUS FOR ADDITIONAL CONVECTION
AS THE AFTERNOON PROGRESSES GIVEN INTERACTION OF BOUNDARIES AND VERY
UNSTABLE AIRMASS. LOCALLY STRONG STORMS POSSIBLE WITH HEAVY RAIN AND
FREQUENT LIGHTNING. DEFLECTION OF STORM TOPS TO THE NORTHEAST ON
VISIBLE IMAGERY ARGUES FOR A MOVEMENT OF SCATTERED STORMS TOWARD THE
EAST COAST LATER IN THE AFTERNOON AND INTO THE EVENING...ESPECIALLY
FOR THE NORTH AND CENTRAL COUNTIES INVOF AND NORTH OF RIDGE AXIS.

TONIGHT...LITTLE MOVEMENT IS ADVERTISED WITH THE E-W RIDGE AXIS
ACROSS THE CENTER OF THE STATE. WIND WILL DROP TO NEAR CALM A COUPLE
HOURS AFTER DARKNESS WITH A FEW LINGERING SHOWERS AND ONLY SCATTERED
CLOUDS.

SAT-SUN...SUB TROPICAL RIDGE PERSISTS OVER AREA WITH UPPER LEVEL
RIDGE BUILDING OVER STATE. SEA BREEZE FORMATION WILL OCCUR FAIRLY
EARLY SOUTH OF THE CAPE WITH LIGHT WINDS NEAR RIDGE AXIS AND BE
HARDER TO COME BY TO THE N WITH MORE SWLY LOW LEVEL FLOW. SOME
DRYING INDICATED OVER SRN PART OF THE STATE TO N OF WWD MOVING
TROPICAL WAVE BUT 12Z AVN NOW BACKING OFF ON NWD EXTENT OF DRYING
AND WILL HAVE TO WATCH AS THIS EVOLVES...PLAN TO INDICATE DECREASING
TREND IN SRN MOST GROUP BUT WILL NOT PLAY UP FOR REST OF AREA. TEMPS
ABLE TO REACH MID 90S SOME SPOTS AWAY FROM COAST BOTH DAYS.

MON-WED...LOW LEVEL RIDGE WEAKENS AND DRIFTS S AS FRONTAL BOUNDARY
STALLS OVER GA. UPPER LEVEL TROFFING OVER ERN STATES AND SCT SHOWERS
AND STORMS WILL CONT FOR CWA.

MARINE...WINDS MAINLY S TO SW WITH RIDGE AXIS OVER AREA. WINDS
INCREASING SLIGHTLY NRN SECTIONS LATE SAT AND SUN AS FRONTAL SYS
MOVES INTO SE STATES. NO HIGHLIGHTS.

PRELIMINARY NUMBERS...

DAB BB 073 093/073 094 52342
MCO BB 074 094/074 095 52342
MLB BB 074 092/074 092 52232

.MLB...NONE.

PENDERGRAST/GLITTO

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 9, 4:35 PM EDT	Severe Thunderstorm Warning	MLB	Okeechobee	45 min
Jul 9, 4:55 PM EDT	Severe Thunderstorm Warning	MLB	Lake, Orange, Seminole	50 min
Jul 9, 6:13 PM EDT	Severe Thunderstorm Warning	MLB	Volusia	42 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.