Alert archive / Florida / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 9, NWS Melbourne, FL

April 25, 1999Orange County, Osceola County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at Apr 25, 1999, 3:39 PM EDT for Orange County, Osceola County, Florida. It was in force for 46 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
Apr 25, 1999, 3:39 PM EDT (19:39 UTC)
Expired
Apr 25, 1999, 4:25 PM EDT
In force
46 min
Issued by
NWS Melbourne, FL
Area
Whole counties

Counties Orange County, FL, Osceola County, FL

The radar

The Melbourne radar (KMLB), 60 km from the middle of the area, began a volume at 19:38 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 25, 3:50 PM EDTHail 0.75Orlando Intl Arpt, 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, 7.7 hours before the alert went out and 132 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 1999-04-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 1999-04-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 37 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1599 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
37 m²/s²
0-3 km storm-relative helicity
42 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 251943 RRA
SVRMLB
FLC095-097-252025-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MELBOURNE FL
339 PM EDT SUN APR 25 1999

THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED A

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

* UNTIL 425 PM EDT

* AT 340 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 10 MILES SOUTHEAST OF ORLANDO INTERNATIONAL
  AIRPORT.  MOVEMENT WAS SOUTHEAST AT 15 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
    THIS STORM WILL MOVE ACROSS LAKE MARY JANE BY 345 PM AND ALONG
    HIGHWAY 532 BY 410 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 Apr 25, 2:28 PM EDT, 1 hour 11 minutes earlier.

Area forecast discussion, Apr 25, 2:28 PM EDT, 1 hour 11 minutes before
EAST CENTRAL FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
228 PM EDT SUN APR 25 1999

CURRENTLY...EAST COAST SEA BREEZE FINALLY MOVING INLAND WITH
ISOLATED THUNDERSTORMS DEVELOPING SOUTH OF CAPE CANAVERAL. VIS SAT
SHOWS SCT CU DEVELOPING OVER FA AS CONVECTIVE TEMPS ARE REACHED. LOW
CLOUDS STILL LINGERING OVER N FLORIDA AS WEAK COLD FRONT MOVE INTO
THAT AREA.

SHORT TERM...AS SEA BREEZE MOVES INLAND YOU CAN EXPECT MORE
WIDELY SCATTERED THUNDERSTORM DEVELOPMENT IN THE MODERATELY UNSTABLE
ATMOSPHERE OVER FA. COLD FRONT WILL BECOME STATIONARY OVER
N FL WHICH SHOULD TRIGGER SHOWERS AND THUNDERSTORMS TONIGHT FOR N
PTN OF FA. SCATTERED TSRA OVER FA SHOULD END BY LATE EVENING
W/PARTLY CLOUDY SKIES EXPECTED OVERNIGHT.

LONG TERM...MODELS ARE IN GENERAL AGREEMENT IN ESSENTIALLY HANGING
UP THE FRONTAL BOUNDARY MAINLY TO THE NORTH OF THE FA THROUGH TUE.
THE PRE-FRONTAL TROUGH SHOULD CONTINUE TO MEANDER ACROSS THE CENTRAL
PART OF THE FA ON MON...AND WITH A STRONGER EXPECTED EAST COAST SEA
BREEZE...MAY BE AFTERNOON SCATTERED TSRA. WILL GO ALONG WITH THE
MODELS SOLUTION ON THIS AS BELIEVE THERE WILL STILL BE ENOUGH PWAT
ACROSS THE FA AROUND 1.5 INCHES AND POSSIBILITY OF BOUNDARY
COLLISIONS. DO BELIEVE THAT PRE-FRONTAL TROUGH SHOULD MAINLY AFFECT
CENTRAL AND NORTHERN PORTIONS OF THE FA ON MONDAY AND SOUTHERN
SECTIONS WILL HAVE LESSER POPS IN 30 PERCENT CATEGORY AS OPPOSED TO
40 POPS ELSEWHERE.

AS FOR MON NIGHT...WILL CARRY 30 EVENING POPS IN NORTHERN AND
CENTRAL SECTIONS AND ONLY 20 PERCENT EVENING POPS FOR SOUTHERN
SECTIONS. MODEL TIME SECTIONS AND FORECAST SOUNDINGS INDICATE THAT
PWAT VALUES AND SOME SLIGHT RIDGING WILL OCCUR IN ADVANCE OF THE
NEXT COLD FRONT MOVING THROUGH THE CENTRAL U.S. BY TUESDAY TO PUSH
LEFT-OVER MOISTURE AND OLD FRONTAL BOUNDARY OUT OF THE FA. WILL ONLY
PUT IN A 20 POP FOR THE FA ON TUE W/LIMITED AMOUNT OF MOISTURE
AVAILABLE AND A LACKING BOUNDARY TO WORK WITH THE SEA BREEZE.

AS FOR TEMPS...WILL GO CLOSE TO NGM NUMBERS THRU THE FORECAST
PERIODS.

.MARINE...WILL INCREASE WINDS 10 TO 15 KTS FROM SE BY MON
W/APPROACHING BOUNDARY INTO THE COASTAL WATERS. WILL BUILD SEAS TO 3
TO 5 FT AND THEN LESSEN THEM ALONG W/WINDS BY MON NGT/TUE. IN
EXTENDED OUTLOOK...WILL INCREASE WINDS/SEAS W/NEXT FRONT MAKING IT
INTO COASTAL WATERS BY WED NGT.

.PRELIMINARY NUMBERS...
DAB BB 066/082 066/087 068 11342
MCO BB 067/087 068/091 070 11342
MLB BB 072/084 069/088 071 11343

.MLB NONE...

BORZILLERI/TROUTMAN

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.