FXUS62 KMLB 241939 CCA
AFDMLB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
239 PM EST THU DEC 24 2009
...LIKELY RAIN CHANCES LATE TONIGHT INTO TOMORROW WITH ISOLATED
STRONG/SEVERE STORMS POSSIBLE...
.DISCUSSION...TONIGHT...A COLD FRONT AND ASSOCIATED SQUALL LINE
WILL MOVE ACROSS THE FL PANHANDLE AND THE EASTERN GULF...THEN
APPROACH WEST CENTRAL FLORIDA LATE TONIGHT. MOISTURE WILL
CONTINUE TO INCREASE NORTHWARD OVER THE AREA AHEAD OF THIS SYSTEM
AS WINDS SWITCH TO THE SOUTHEAST. SCATTERED SHOWERS AND ISOLATED
STORMS WILL BE ABLE TO DEVELOP AHEAD OF THIS LINE IN THE MOIST AND
MARGINALLY UNSTABLE AIRMASS WITH UL JET AIDING IN LIFT OVERNIGHT.
INCREASING HELICITY/SHEAR OVER THE AREA WILL CREATE A MORE
FAVORABLE ENVIRONMENT FOR ROTATION TO DEVELOP IN ANY STORMS THAT
FORM AFTER MIDNIGHT TONIGHT. WILL THEREFORE KEEP MENTION OF AN
ISOLATED THREAT FOR ROTATING STRONG TO SEVERE STORMS IN THE
HWO...MAINLY FROM THE ORLANDO AREA NORTHWARD TO LAKE AND VOLUSIA
COUNTIES WHERE GREATEST SHEAR WILL RESIDE.
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.
&&
.AVIATION...PREDOMINANT VFR CONDS EXPECTED THROUGH MIDNIGHT. WILL
THEN SEE SCT SHRA DEVELOP WITH ISO TSRA POSSIBLE LATE TONIGHT INTO
CHRISTMAS DAY AHEAD OF A COLD FRONT THAT WILL CROSS THE AREA
TOMORROW. TEMPO IFR/MVFR CONDS WILL BE POSSIBLE WITH ANY OF THIS
CONVECTIVE ACTIVITY. ADDED LLWS FROM 00-12Z TONIGHT AS STRONG LOW
LEVEL WINDS WILL EXIST OUT OF THE SE AROUND 30-35KTS.
&&
.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.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 67 76 49 63 / 50 60 10 20
MCO 64 76 49 63 / 50 60 20 20
MLB 70 77 51 65 / 50 60 20 20
VRB 72 78 54 69 / 50 60 30 20
LEE 65 74 46 61 / 60 60 10 20
SFB 65 76 49 64 / 50 60 10 20
ORL 66 76 51 63 / 50 60 10 20
FPR 71 78 55 69 / 50 60 30 20
&&
.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.
&&
$$
SHORT TERM/AVIATION...WEITLICH
LONG TERM....SPRATT
