FXUS62 KMLB 250056
AFDMLB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
756 PM EST THU DEC 24 2009
...LIKELY RAIN CHANCES LATE TONIGHT INTO TOMORROW WITH ISOLATED
STRONG/SEVERE STORMS POSSIBLE...
.DISCUSSION...
CURRENT/OVERNIGHT...RADARS DETECTING TWO LINES OF PRECIP OVER THE
NORTHERN GULF. FIRST...CLOSER...WAS MOVING SOUTH TO NORTH ACROSS THE
TALLAHASSEE AREA WHILE A SECOND...WATCH BOXED...WAS MOVING ACROSS
THE PENSACOLA AREA ATTM. THIS AREA HAD MOST/ALL OF THE LIGHTNING AND
SAFE TO SAY THAT THIS WAS THE SQUALL LINE AHEAD OF THE MAIN COLD
FRONT STILL BACK OVER THE MS GULF COAST AREA WITH A TRIPLE POINT
OVER SOUTHERN MS. SEVERAL FACTORS MAY COME INTO PLAY AND LIMIT
STORM POTENTIAL LATE OVERNIGHT. DEEPENING SOUTHERLY FLOW WITH SPACE
CENTER PROFILERS ALREADY SHOWING SOUTHEAST FLOW THROUGH 6000 FEET
THEN SOUTHERLY ABOVE THAT AND THE PRECIP MOTION OVER THE NORTH
CENTRAL GULF WOULD TEND TO VALIDATE THAT. LIMITED INSTABILITY AND
LAYER PRECIPITABLE WATER VALUES TO AROUND 1.8 INCHES. LATEST GFS RUN
SHOWS THE SQUALL LINE WEAKENING SOME AS IT APPROACHES THE WEST SIDE
OF THE PENINSULA BUT HELICITY VALUES REMAIN AROUND 200 OVER THE AREA
TOWARD 12Z/7AM. LATEST LOCAL WRF RUN PLACES THE LLJ OVER THE
APALACHICOLA AREA AND NORTH WITH 25 TO 30 KNOT FRINGE OVERTOP
CENTRAL FLORIDA DURING THE NIGHT. THE ONLY FLY IN THE SO CALLED
OINTMENT WOULD BE THAT THE LATEST RUC80 UPPER LEVEL/250MB JET PROG
PLACED THE NOSE OF A 120 PLUS JET MAX OVER THE NORTHWEST GULF MOVING
ACROSS THE NORTH CENTRAL GULF OVERNIGHT. THIS COULD PROVIDE ENOUGH
DEEP LAYER LIFT AS IT AND THE SQUALL LINE APPROACH THE WEST SIDE OF
THE PENINSULA LATE OVERNIGHT AND MOVE ACROSS THE PENINSULA CHRISTMAS
MORNING. ON THE OTHER SIDE OF THE PENINSULA...SHOWERS IN THE
SOUTHEAST FLOW OVER THE BAHAMA ISLANDS AND EAST COAST OF FLORIDA
COULD EXPERIENCE ENHANCED LOW LEVEL SHEAR AND ACQUIRE ROTATION AS
THEY APPROACH THE COAST LATE OVERNIGHT. LOOKS LIKE IT COULD BE A
LONG NIGHT WATCHING THE RADAR(S). WILL ISSUE ANOTHER HAZARDOUS
WEATHER OUTLOOK ADDRESSING THE LATE NIGHT STORM POTENTIAL. OTHER
THAN CHANGES TO WINDS...BASIC FORECAST REMAINS UNCHANGED EXCEPT FOR
ENHANCED WORDING LATE NIGHT.
&&
.AVIATION...LLWS 08Z-12Z ISM/MCO NORTH. BROKEN-OVERCAST ABOVE
FL120 OCNL BKN035-050 THROUGH 12-14Z. MVFR/IFR AFTER 14Z AS LINE OF
STORMS MOVE QUICKLY ACROSS CENTRAL FLORIDA. VFR EXPECTED AFTER
21-22Z TIME FRAME.
&&
.MARINE...LATEST BUOY REPORTS SHOW SEAS RANGING FROM 5 FEET 6NM
NORTHEAST OF FORT PIERCE INLET TO 7 AND 8 FEET AT BUOYS 012 AND 010
WITH SOUTHEAST WINDS AROUND 20 KNOTS GUSTING TO 27 KNOTS AT BUOY 012
PAST HOUR. WINDS SHOULD INCREASE AND SHIFT TO THE SOUTH OVERNIGHT AS
THE SQUALL LINE AND FRONT APPROACH THE WEST SIDE OF THE PENINSULA.
SMALL CRAFT ADVISORY REMAINS IN EFFECT.
&&
PREVIOUS DISCUSSIONS...
CHRISTMAS DAY...AS MAIN LINE AHEAD OF THE FRONT MOVES INTO CENTRAL
FLORIDA MAY SEE SOME WEAKENING IN THE SHOWER/STORM BAND WITH
REDEVELOPMENT POSSIBLE ALONG THE BOUNDARY AS IT CONTINUES TO PUSH
EAST ACROSS EAST CENTRAL FLORIDA THROUGH THE AFTERNOON. CURRENT
FORECAST TRENDS HAVE FRONT PUSHING INTO LAKE/W ORANGE/NW
OSCEOLA/INTERIOR VOLUSIA COUNTIES BY MID/LATE MORNING AND FARTHER
EAST LOCATIONS THROUGH THE AFTERNOON. WILL KEEP LIKELY RAIN CHANCES
(60%) AND A SLIGHT CHANCE OF THUNDERSTORMS IN THE FORECAST FOR
TOMORROW MAINLY ASSOCIATED WITH THE PASSAGE OF THE COLD FRONT.
ISOLATED STRONG TO SEVERE STORMS WILL STILL BE POSSIBLE AHEAD OF THE
FRONT WITH MAIN THREAT TRANSITIONING TO STRONG/DAMAGING WIND
GUSTS AS WINDS BECOME MORE UNIDIRECTIONAL. HIGHS WILL REACH THE
MID/UPPER 70S TOMORROW BEFORE FROPA WITH TEMPS THEN GRADUALLY
DECLINING BEHIND THE BOUNDARY.
FRIDAY NIGHT-SATURDAY NIGHT...FRONTAL BOUNDARY AND ASSOCIATED
SHOWERS/STORMS WILL DROP SOUTH OF CWA FRIDAY NIGHT...ALTHOUGH
SMALL PRECIP CHANCE WILL BE MAINTAINED THROUGH THE EVENING SE
PART. LIGHT NW/N FLOW WILL ALLOW DRIER AIR TO FILTER INTO THE
REGION BRIEFLY SATURDAY...RESULTING IN A PRECIP FREE DAY BUT
WITH PARTIAL-CONSIDERABLE MID-LEVEL CLOUDINESS. WEAK LOW PRESSURE
DEVELOPMENT OVER THE CENTRAL GULF LATE SATURDAY MAY PROMPT
DEVELOPMENT OF WARM FRONTAL BOUNDARY OVER PENINSULA WITH ONSET OF
WEAK OVERRUNNING PATTERN CAUSING CLOUDS TO THICKEN AND SMALL
CHANCE FOR LIGHT RAIN DEVELOPMENT. MIN TEMPS SEVERAL DEGREES BELOW
CLIMO...WITH HIGH TEMPS RANGING FROM AROUND 60 NORTH TO 70
SOUTH...SOME 5-10 DEGREES BELOW CLIMO.
SUN-THU...AS IS OFTEN THE CASE DURING EL NINO PERIODS...MOISTURE
LURKING TO THE SOUTH WILL LIFT NORTHWARD AS WEAK OVERRUNNING
PATTERN CONTINUES SUNDAY WITH INCREASING SW FLOW ALOFT. EXPECT
CONSIDERABLE MULTI-LEVEL CLOUDS AND SMALL CHANCE FOR STRATIFORM
PRECIP. IF PATTERN OF ISENTROPIC LIFT INTENSIFIES...MAY NEED TO
TREND POPS HIGHER...BUT BELIEVE QPF WILL REMAIN LOW. HIGHER
PRESSURE GRADUALLY BUILDS INTO CENTRAL FLORIDA EARLY NEXT WEEK AS
THE GFS SHOWS THE NEXT WEATHER SYSTEM TAKING SHAPE IN THE WESTERN
GULF MID WEEK THEN SLIDING ACROSS FLORIDA THURSDAY. IT APPEARS
LIGHT NORTH/NORTHWEST SURFACE FLOW WILL BE MAINTAINED INTO
WEDNESDAY...FOLLOWED BY QUICK MOISTENING AS A RETURN FLOW SETS UP.
A STRONG JET WILL LIE OVERHEAD OVER THE WEEKEND....ENHANCING
PERIODS OF PREVAILING BROKEN-OVERCAST MID/HIGH LEVEL CLOUDINESS.
WILL LEAVE FORECAST DRY MON-WED THEN INTRODUCE SCATTERED
SHOWERS/ISOLATED STORMS THURSDAY. HIGHS ARE FORECAST TO RUN A FEW
TO SEVERAL DEGREES BELOW NORMAL WITH MAX TEMPERATURES MAINLY IN
THE 60S...BUT A FEW READINGS NEAR 70 DEGREES WILL BE POSSIBLE AND
MANLY ALONG THE TREASURE COAST. LOWS IN GENERAL WILL ALSO AVERAGE
BELOW SEASONAL AND MAINLY IN THE 40S WITH A FEW UPPER 30S POSSIBLE
ACROSS RURAL AREAS OF OUR NORTH & WESTERN INTERIOR AWAY FROM THE
I-4 CORRIDOR...TRENDING UPWARD TO NEAR CLIMO BY END OF FORECAST
PERIOD.
&&
.MARINE...SE WINDS WILL CONTINUE TO INCREASE INTO TONIGHT AHEAD OF
AN APPROACHING COLD FRONT WITH SPEEDS AROUND 20 KTS NEARSHORE AND
UP TO 20-25 KTS OFFSHORE. THESE WINDS WILL BUILD SEAS UP TO 7-9 FT
THROUGH TOMORROW AHEAD OF THE FRONTAL BOUNDARY. THIS WILL CONTINUE
TO CREATE HAZARDOUS BOATING CONDITIONS WITH AN SCA CONTINUING FOR
THE ENTIRE COASTAL WATERS THROUGH THE AFTERNOON HOURS ON CHRISTMAS
DAY.
OFFSHORE FLOW GRADUALLY LESSENS SATURDAY AND VEERS MORE NORTHERLY
SATURDAY NIGHT. ONSHORE FLOW EARLY SUNDAY BECOMES BRIEFLY
SOUTHERLY LATER SUNDAY AS WARM-FRONT DEVELOPS THEN REVERTS TO NW
LATE SUNDAY AS WEAK LOW REACHES THE ATLANTIC. OFFSHORE FLOW THEN
BUILDS MON-TUE AND MAY REACH SCEC/SCA LEVEL...MAINLY ACROSS
OFFSHORE WATERS.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 4 PM EST FRIDAY FOR COASTAL WATERS
FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE OUT 20 NM-
COASTAL WATERS FROM SEBASTIAN INLET TO JUPITER INLET OUT 20
NM-COASTAL WATERS FROM VOLUSIA BREVARD COUNTY LINE TO
SEBASTIAN INLET OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 4 AM EST SATURDAY FOR WATERS FROM
FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE 20 TO 60 NM
OFFSHORE-WATERS FROM SEBASTIAN INLET TO JUPITER INLET 20 TO
60 NM OFFSHORE-WATERS FROM VOLUSIA BREVARD COUNTY LINE TO
SEBASTIAN INLET 20 TO 60 NM OFFSHORE.
&&
$$
WIMMER/CRISTALDI
