FXUS62 KMLB 251007
AFDMLB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
507 AM EST FRI DEC 25 2009
.DISCUSSION...
...LIKELY RAIN CHANCES TODAY AS THE DAY PROGRESSES WITH ISOLATED
STRONG/SEVERE STORMS POSSIBLE...
CHRISTMAS DAY-TONIGHT...A WARM FRONTAL BOUNDARY CONTINUES TO LIFT
NORTH OF THE PENINSULA INTO THE SOUTHEAST U.S. EARLY THIS MORNING. A
COLD FRONT WAS LOCATED ACROSS THE PANHANDLE AND EXTENDED SOUTHWARD
INTO THE EASTERN GOMEX. FURTHER ALOFT AN UPPER LEVEL SYSTEM WAS
LOCATED OVER THE MISSISSIPPI VALLEY.
SOME OVERNIGHT & EARLY MORNING CONVECTION ALONG THE EAST COAST AND
OVER THE NEAR SHORE ATLANTIC WATERS HAS SHOWN SOME ROTATION ALONG
WITH SOME STRONG WINDS JUST OFF THE SURFACE. THE THREAT FOR ANY
ROTATION WILL CONTINUE TO DECREASE THROUGH THIS MORNING AS WIND
PROFILES VEER MORE UNI-DIRECTIONAL AND AS BEST MID-LEVEL FORCING
PROSPECTS LIFT NORTH AWAY FROM THE AREA. OUR PRESENT LOW-LEVEL
SOUTHEAST WINDS WILL CONTINUE TO VEER TO SOUTHERLY PAST DAYBREAK AND
THEN SOUTHWESTERLY THIS AFTERNOON WITH THE APPROACH OF THE COLD
FRONT. ALSO...THE STEERING WINDS FOR CONVECTIVE CELLS CONTINUE TO
VEER TO SOUTHERLY WHICH WILL KEEP CONVECTION OVER THE COASTAL WATERS
MOSTLY AWAY FROM THE COAST.
CHANCES WILL EXIST FOR ISOLATED/SCATTERED SHOWERS TO DEVELOP AHEAD
OF A PRE-FRONTAL BAND OF CONVECTION AND MOVE NORTH/NORTHEASTWARD
ANYWHERE ACROSS EAST CENTRAL FLORIDA THIS MORNING. A PRE-FRONTAL
BAND OF CONVECTION SHOULD APPROACH LAKE AND VOLUSIA COUNTIES BY LATE
MORNING/EARLY AFTERNOON WITH SHOWER CHANCES INCREASING AS THE DAY
GROWS OLD (FROM NORTHWEST TO SOUTHEAST) ACROSS THE AREA. FOR THE
GRIDS/ZONES WILL GO WITH LIKELY (60%) SHOWERS AND A SLIGHT CHANCE
FOR LIGHTNING STORMS. RECENT SATELLITE AND SHORT TERM MODELS ARE
LEAVING LITTLE CONFIDENCE THAT A SOLID AND ORGANIZED SQUALL-LINE
WILL BE ABLE TO RE-GENERATE AND MOVE WEST TO EAST ACROSS THE
PENINSULA LATER TODAY. THE GFS STILL REMAINS FASTER WITH THE FRONT
THAN THE NAM. THE LATER THE BOUNDARY ARRIVES ACROSS EAST CENTRAL
FLORIDA THE GREATER THE CHANCE FOR HIGHER AFTERNOON MAXES AS WELL AS
FOR A FEW STRONG/MARGINALLY SEVERE STORMS WITH POSSIBLE DAMAGING
WIND GUSTS...CLOUD TO GROUND LIGHTNING AND LOCALLY HEAVY RAINS THE
MAIN THREATS. INSTABILITY REMAINS MARGINAL AT BEST. THE PRE-FRONTAL
BAND OF PRECIPITATION WILL CONTINUE SOUTHEASTWARD THROUGH THE
REMAINDER OF THE AFTERNOON AND EVENING PUSHING OFFSHORE & AWAY FROM
THE COAST LATER IN THE EVENING AND OVERNIGHT. WILL LEAVE A SMALL
MENTION SHOWERS IN THIS EVENING MAINLY SOUTHWARD FROM THE SPACE
COAST UNTIL FRONT CLEARS THE COVERAGE WARNING AREA.
FOR HIGHS...MIDDLE/UPPER 70S MOST EVERYWHERE WITH A FEW READINGS
AROUND 80 DEGREES POSSIBLE FURTHER SOUTHWARD ACROSS OKEECHOBEE AND
THE TREASURE COAST. LOWS TONIGHT ARE EXPECTED TO DROP INTO THE UPPER
40S TO NEAR 50 DEGREES ALONG AND NORTH OF THE I-4 CORRIDOR. SOME
MIDDLE 40S CANNOT BE RULED OUT FOR RURAL AREAS AND NORMALLY COLDER
LOCATIONS. FURTHER SOUTHWARD LOWS WILL RANGE FROM NEAR 50 DEGREES TO
MIDDLE 50S AS COOLER & DRIER AIR SWEEP DOWN BEHIND THE FRONT.
SAT-SUN...LIGHT SHALLOW N/NW FLOW WILL ALLOW DRIER AIR TO FILTER
INTO THE REGION BRIEFLY SATURDAY...RESULTING IN A PRECIP FREE DAY
BUT WITH SOME MID AND UPPER CLOUDINESS. AS IS OFTEN THE CASE
DURING EL NINO PERIODS...MOISTURE LURKING TO THE SOUTH WILL LIFT
NORTHWARD AS WEAK OVERRUNNING PATTERN DEVELOPS SAT NIGHT AND
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. MIN TEMPS
SEVERAL DEGREES BELOW CLIMO...WITH HIGH TEMPS RANGING FROM LOWER
60S NORTH TO LOWER 70S SOUTH...SOME 5-10 DEGREES BELOW CLIMO.
MON-THU...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. 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. THE ECMWF IS CONSIDERABLY
SLOWER WITH THE TIMING OF THE NEXT FRONT INDICATING FRIDAY AS
HAVING THE HIGHEST RAIN CHANCES.
&&
.AVIATION...
LLWS THRU AROUND 14Z ISM/MCO NORTH. AREAS BKN035-050 THROUGH 12Z-
14Z. MVFR/IFR AFT 15Z AS SHRA & ISOLD TSRA MOVE QUICKLY ACROSS
ECFL. VFR EXPECTED AFTER 00Z TIMEFRAME. SFC WIND GUSTS COULD
LOCALLY EXCEED 35 KTS FROM STRONGER CELLS.
&&
.MARINE...
CHRISTMAS DAY-TONIGHT...STRONG SOUTHEAST FLOW AHEAD OF AN
APPROACHING COLD FRONT WILL SLOWLY VEER TO MORE SOUTHERLY BY LATE
IN THE MORNING AND SOUTH/SOUTHWESTERLY THROUGH THE AFTERNOON.
SPEEDS OF 20 TO 25 KNOTS WITH HIGHER GUSTS AWAY FROM THE COAST
WILL GRADUALLY DECREASE AS THE PGRAD WEAKENS. SEAS ARE EXPECTED TO
REMAIN ELEVATED 7-9 FT OFFSHORE. WILL KEEP CURRENT SCA IN PLACE
WITH NEAR SHORE WATERS EXPIRATION AT 21Z (4PM) AND OFFSHORE WATERS
CONTINUING OVERNIGHT.
MARINERS WILL NEED TO BE WEARY OF A FEW STRONG SHOWERS AND ISOLATED
LIGHTNING STORMS THIS MORNING AND LATER TODAY. EARLY MORNING SHOWERS
OFF OF THE SPACE AND TREASURE COASTS HAVE EXHIBITED ROTATION &
STRONG WINDS JUST OFF THE SURFACE. CANNOT RULE OUT POSSIBLE FUNNEL
CLOUDS AND WATER SPOUTS WITH ANY MORNING ACTIVITY. LATER IN THE MORNING
AND INTO THE AFTERNOON THE THREAT WILL BE MAINLY FOR STRONG WINDS IN
EXCESS OF 34 KTS...LOCALLY HEAVY DOWNPOURS AND OCCASIONAL CLOUD TO
WATER LIGHTNING.
SAT-TUE...NW WINDS 10-15 KNOTS MAY KEEP COMBINED SEAS AROUND 7
FEET OFFSHORE SO HAVE EXTENDED THE ADVISORY INTO SAT AM. PGRAD
WEAKENS SAT NIGHT AND SUNDAY AS WINDS TURN NORTH THEN NORTHEAST.
REINFORCING COLD FRONT IS FORECAST TO CROSS THE WATERS EARLY
MONDAY AND INCREASE THE OFFSHORE FLOW INTO TUE. WILL PROBABLY NEED
AN ADVISORY FOR THE OFFSHORE WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 76 49 64 46 / 60 10 10 20
MCO 77 53 65 47 / 60 10 10 20
MLB 77 53 70 51 / 60 20 10 20
VRB 79 54 72 54 / 60 30 10 20
LEE 75 47 63 44 / 60 10 10 20
SFB 77 51 65 46 / 60 10 10 20
ORL 77 52 66 49 / 60 10 10 20
FPR 79 56 72 53 / 60 30 10 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON 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
SEBASTIAN INLET TO JUPITER INLET 20 TO 60 NM OFFSHORE.
SMALL CRAFT ADVISORY UNTIL 11 AM EST SATURDAY FOR WATERS FROM
FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE 20 TO 60 NM
OFFSHORE-WATERS FROM VOLUSIA BREVARD COUNTY LINE TO
SEBASTIAN INLET 20 TO 60 NM OFFSHORE.
&&
$$
SHORT TERM...SEDLOCK
LONG TERM....KELLY
