Severe Thunderstorm Warning 51, NWS Melbourne, FL

EAST CENTRAL FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
245 AM EST FRI DEC 20 2002

SURFACE ANALYSIS SHOWS A DEEP LOW PRESSURE CENTERED ACROSS THE GREAT
LAKES REGION WITH A TRAILING COLD FRONT EXTENDING WELL SOUTH INTO
THE ERN GOMEX. MOISTURE IS TRYING TO STREAM NORTH AHEAD OF THE FRONT
W/ DEWPOINTS NOW IN THE MID 60S ACROSS CEN FL AND LOWER 70S OVR SRN
FL...BUT EVENING SOUNDINGS AND GOES SOUNDER DATA SHOW MOISTURE DEPTH
IS LIMITED W/ PWATS GENERALLY LESS THAN 1.3 INCHES. THE SHARP ROPE
LIKE CLOUD ALONG THE FRONT OVR THE GOMEX INDICATES STRONG
CONVERGENCE ALONG THE BOUNDARY AND A DECENT LINE OF TSTMS IF FORMING
ALONG AND AHEAD OF THE FRONT OVR THE WARM LOOP CURRENT. THE MAIN
QUESTION FOR TDY IS WHAT IS GOING TO HAPPEN TO THESE STORMS AS THEY
MOVE INTO COLDER SHELF WATERS AND A MORE STABLE AIRMASS OVR THE FL
PENINSULA.

A GOOD LLJ WILL PRODUCE H85 WINDS NR 40 KTS TDY SEEMINGLY SUPPORTING
ORGANIZED TSTMS. HOWEVER...MESO ETA SHOWED CAPE VALUES IN EXCESS OF
2000 J/KG IN THE AREA THE TSTMS HAVE FORMED OVR THE WARM LOOP
CURRENT...BUT THESE TSTMS WILL MOVE OUT OF THIS HIGH BUOYANCY AREA
INTO A REGION WITH CAPE VALUES NR 500 J/KG OR LESS. WITH LACK OF UPR
LVL SUPPORT THIS FAR SOUTH...EXPECT THIS WILL LEAD TO A WEAKENING
LINE OF TSTMS AND POSSIBLY MAINLY JUST RWS ACROSS THE NTH SECTIONS
BY THE TIME THIS CONVECTION REACHES THE AREA (ALEADY EVIDENT ON
LATEST RADAR IMAGERY IN NRN PORTINS OF THE LINE). PLACING THE AWIPS
DIS/SPD TOOL ON THE ROPE CLOUD SHOWS THE FRONT WILL REACH MUCH OF
THE AREA THIS MORNING FAVORING THE QUICKER MODELS ON TIMING. THE
BAND OF CONVECTION WILL REACH THE SERN ZONES THE LATEST (NOONISH??).
THIS MAY GIVE THESE AREAS A LITTLE TIME TO WARM UP SLIGHTLY AND MESO
ETA DOES SHOW SOME HIGHER CAPE VALUES NEAR 1000 J/KG EAST OF THE
LAKE OKEECHOBEE (AND OVR THE ATL WATERS) BY MID DAY LEADING TO A
LITTLE BETTER CHC OF MORE SIGNIFICANT TSTMS/RAINFALL IN THOSE ZONES.
THAT BEING SAID THINK MOISTURE CONVERGENCE ALONG THE FRONT IS ENOUGH
TO SUPPORT THE MAV 70 POPS ALL ZONES AND PLAN TO GO WITH THAT BARING
ANY LAST MINUTE RADAR TRENDS SUGGESTING OTHERWISE. SHOULD BE A QUICK
SHOT OF PRECIP...MAINLY IN THE MORNING IN THE NTH AND ENDING BY AFTN
EVEN IN SRN SECTIONS AND WILL TRY TO SHOW THIS TIMING IN THE ZFP.

SFC HIGH BUILDS INTO CEN FL BRINGING COOLER AND MUCH DRIER AIR TO
THE REGION ON SAT. DEGREE OF H85 COOLING SUPPORTS COOLER MAV TEMPS
AND WILL LEAN THAT DIRECTION. THE COOLEST NIGHT WILL BE SAT NIGHT AS
THE HIGH SETTLES RIGHT OVR THE REGION PROVIDING OUTSTANDING RAD
COOLING...ESP GIVEN THE VERY DRY CONDITIONS. SO EVEN THOUGH THIS IS
NOT THE COLDEST AIRMASS...TEMPS IN THE UPR 30S TO LOWER 40S IS NOT
OUT OF THE QUESTION SUN MORNING.

THE HIGH PUSHES OFF THE EAST COAST BY MONDAY ALLOWING RETURN FLOW.
GFS CONTINUES TO SHOW A STRONG SRN STREAM S/WV MVS ACROSS THE THE
DEEP SOUTH CHRISTMAS EVE AND CHRISTMAS. THE GFS HAS REMAINED PRETTY
CONSISTENT IN HANDLING THIS SYSTEM THE LAST FEW RUNS...ALTHOUGH THE
EXACT DETAILS (ESP REGARDING THE SFC LOW) HAVE DIFFERED SLIGHTLY.
OVERALL THIS SYSTEM APPEARS SIMILAR TO THE LAST STORM THAT PRODUCED
SOME SVR WX ACROSS THE REGION...BUT ITS MUCH TO EARLY TO TELL. WILL
HAVE TO STAY TUNED AND SEE WHAT HAPPENS AS TIME DRAWS NEARER...BUT
IT APPEARS CHRISTMAS EVE AND CHRISTMAS DAY MAY BE ON THE MESSY SIDE
THIS YEAR.

MARINE...LOW PRESSURE SYSTEM TO THE NORTH PRODUCING SCA CONDITIONS
ACROSS THE COASTAL WATERS. WILL FORECAST 25 KTS AND GUSTY ACROSS THE
NRN WATERS AND SLIGHTLY LESS IN THE STH. WINDS WILL SHIFT W TO NW
TODAY BUT REMAIN ABOVE ADVISORY CRITERIA AT LEAST INTO TONIGHT.
THINGS WILL QUIET DOWN SIGNIFICANTLY OVR THE WEEKEND AS HIGH
PRESSURE SETTLES INTO THE REGION...BEFORE WINDS PICK UP TO SCA
STRENGTH AGAIN BY TUE AHEAD OF THE NEXT STRONG STORM SYSTEM.

FIRE WEATHER...WILL RAISE FIRE WEATHER WATCH ON SAT FOR NRN INTERIOR
ZONES. VERY DRY LOW LVL AIRMASS (PWATS .15-.20) AND DWPTS PROGD
IN THE UPR 20S/LWR 30S IN THE AFTN SHOULD ALLOW MIN RHS TO REACH
NEAR CRITICAL DURATIONS ACROSS NRN INTERIOR SECTIONS.

PRELIM...
DAB WU 070/042 062/039 070 700
MCO WU 070/043 063/042 072 700
MLB WU 074/044 064/044 071 700

.MLB...SMALL CRAFT ADVISORY FLAGLER BEACH TO JUPITER INLET.
    ...FIRE WEATHER WATCH SAT AFTN FOR LAKE...INLAND VOLUSIA...
       SEMINOLE...ORANGE AND OSCEOLA COUNTIES.

PUBLIC/MARINE...GITTINGER
AVIATION/FIRE...VOLKMER

AMZ550-555-570-575-FLZ041-044>047-053-054-058-059-064-141-144-147-
201700-

EAST CENTRAL FLORIDA HAZARDOUS WEATHER OUTLOOK...CORRECTED WORDING
NATIONAL WEATHER SERVICE MELBOURNE FL
617 AM EST FRI DEC 20 2002

.DAY ONE...

...SOME STRONG THUNDERSTORMS POSSIBLE THIS MORNING INTO EARLY
AFTERNOON...

A LINE OF SHOWERS AND THUNDERSTORMS ALONG A COLD FRONT WILL PUSH
EAST THIS MORNING ACROSS THE FLORIDA PENINSULA. THUNDERSTORMS
MAY BE SOMEWHAT HINDERED BY COOL TEMPERATURES AND A SLIGHTLY MORE
STABLE AIRMASS IN PLACE EARLY THIS MORNING. HOWEVER...AREAS EAST OF
INTERSTATE 4...AND SOUTH OF ORLANDO WILL HAVE SOME OPPORTUNITY FOR
HEATING BEFORE THE STORMS ARRIVE A LITTLE LATER THIS MORNING. WARMER
TEMPERATURES WILL LEAD TO A SLIGHTLY MORE UNSTABLE ATMOSPHERE IN FAR
EASTERN AND SOUTHERN SECTIONS. THIS WILL PRODUCE AN INCREASED CHANCE
OF STRONGER STORMS IN THESE AREAS...PRODUCING LOCALLY HEAVY
RAINFALL...GUSTY WINDS AND DANGEROUS LIGHTNING STRIKES. CURRENTLY THE
RISK SEVERE THUNDERSTORMS APPEARS TO BE LOW...HOWEVER THE STORMS WILL
BE MOVING NORTHEAST AT NEARLY 40 MPH AND IT WILL NOT TAKE MUCH TO
PRODUCE THUNDERSTORM WIND GUSTS OF 40 TO 50 MPH TODAY.

FOR MARINERS...A LOW PRESSURE SYSTEM NORTH OF THE REGION IS PRODUCING
SOUTH TO SOUTHWEST WINDS OF 25 KNOTS WITH HIGHER GUSTS. THIS IS
PRODUCING ROUGH CHOPPY SEAS IN THE FLORIDA ATLANTIC WATERS AND SMALL
CRAFT ADVISORIES HAVE BEEN POSTED. IN ADDITION...MARINERS SHOULD
REMAIN ALERT FOR THE POSSIBILITY OF STRONG THUNDERSTORMS MOVING OFF
THE EAST COAST LATER THIS MORNING AND INTO THE EARLY AFTERNOON.

.SPOTTER CALL TO ACTION STATEMENT...

FORMAL ACTIVATION IS NOT ANTICIPATED...HOWEVER SPOTTERS ARE REQUESTED
TO SELF ACTIVATE SHOULD ANY WARNINGS BE ISSUE YOUR AREA.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH CHRISTMAS...

ANOTHER STRONG LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE TEXAS GULF
COAST EARLY NEXT WEEK. THIS SYSTEM IS EXPECTED TO BRING A CHANCE OF
THUNDERSTORMS THE CENTRAL FLORIDA ON CHRISTMAS EVE AND EARLY
CHRISTMAS MORNING. IT IS MUCH TOO EARLY TO DETERMINE THE EXACT
IMPACTS AND POTENTIAL FOR SEVERE WEATHER ASSOCIATED WITH THIS
STORM. RESIDENTS ARE URGED TO CONTINUE TO MONITOR THE FORECASTS
REGARDING THIS WEATHER SYSTEM.

FOR FURTHER INFORMATION GO ONLINE TO WWW.WEATHER.GOV...AND CLICK ON
EAST CENTRAL FLORIDA.

FLZ045-144-201230-

SPECIAL WEATHER STATEMENT FOR WIND GUSTS UP TO 55 MPH
NATIONAL WEATHER SERVICE MELBOURNE FL
645 AM EST FRI DEC 20 2002

...A LINE OF STRONG STORMS CAPABLE OF PRODUCING WIND GUSTS UP TO 55
MPH MOVING INTO CENTRAL LAKE COUNTY AND NORTHWESTERN ORANGE COUNTY...

AT 645 AM EST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF STORMS CAPABLE OF PRODUCING STRONG WIND GUSTS 13 MILES WEST
OF MASCOTTE...MOVING NORTHEAST AT 40 MPH.

LOCATIONS IN THE PATH OF THE STORM WHICH MAY EXPERIENCE STRONG WINDS
INCLUDE MASCOTTE...CLERMONT...CLERMONT...THE FLORIDA TURNPIKE...AND
FERNDALE.

IF THE STORMS MOVE INTO YOUR AREA...SEEK SAFE SHELTER IMMEDIATELY.

15

AMZ550-555-570-575-FLZ041-044>047-053-054-058-059-064-141-144-147-
201500-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MELBOURNE FL
852 AM EST FRI DEC 20 2002

...STRONG STORMS QUICKLY APPROACHING THE EAST COAST...

AT 850 AM...DOPPLER RADAR INDICATED A LINE OF STRONG THUNDERSTORMS
MOVING BRISKLY NORTHEAST AT 40 MPH AND APPROACHING THE EAST COAST.
THE STORMS WERE MOVING ACROSS THE VOLUSIA COUNTY COAST SOUTH OF
DAYTONA BEACH...AND WILL ALSO REACH THROUGH BREVARD COUNTY AND THE
ADJACENT COASTLINE BETWEEN 9 AND 930 AM NORTH OF COCOA BEACH...AND
FROM 930 TO 10 AM SOUTH OF COCOA BEACH. STRONG STORMS WILL ALSO MOVE
ACROSS OSCEOLA COUNTY AND THROUGH EASTERN SECTIONS OF ORANGE AND
SEMINOLE COUNTIES.

IN ADDITION TO HEAVY DOWNPOURS AND CLOUD TO GROUND LIGHTNING...THE
STORMS MAY PRODUCE STRONG WIND GUSTS AROUND 40 MPH AS THEY PASS.
PERSONS SHOULD TAKE SHELTER INDOORS BEFORE STORMS APPROACH AND
BOATERS ON THE INTRACOASTAL AND COASTAL WATERS SHOULD MOVE TO SAFE
HARBOR WELL AHEAD OF THESE FAST APPROACHING STORMS.

GLITTO