FXUS62 KJAX 120230
AFDJAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
930 PM EST FRI DEC 11 2009
...INCREASING RAINS ACROSS THE AREA THIS WEEKEND...
...FLOOD WATCH FOR N TIER OF COUNTIES...
.UPDATE...SFC DATA SHOWS A STRONG HIGH CENTERED OVER CAROLINAS AT
1033 MB WITH LLVL NELY FLOW OVER THE AREA. ALOFT...DEEP LAYER HIGH
PRESSURE SYSTEM IS LOCATED OVER THE BAHAMAS WITH SWLY TO W FLOW
ALOFT DRAWING MOISTURE UP OVER THE GULF COAST STATES AND INTO OUR
CWA. A FEW DISTURBANCES ARE MOVING THROUGH THE WSW FLOW CREATING
SOME ENHANCED AREAS OF LIGHT TO MODERATE RAIN FROM THE CENTRAL
GULF COAST AND ACROSS OUR CWA. THE 00Z JAX SOUNDING SHOWS THE
N-NELY FLOW IS SHALLOW TO ABOUT 3 KFT THEN TURNS TO MORE WLY
COMPONENT ALOFT. VERY MOIST CONDITIONS BETWEEN 7 AND 16 KFT AS THE
OVERRUNNING CLOUDS AND AREAS OF LIGHT PRECIP MOVE THROUGH THE
AREA. DRIEST LOW LEVEL AIR IS ACROSS THE NRN HALF OF THE AREA AND
ANTICIPATE LITTLE IF ANY RAIN ACCUMULATION THERE FOR NOW. FOR
THE SRN AREAS...LLVL MOISTURE HAS INCREASED SO WILL HAVE POPS
GENERALLY INCREASING FROM N TO S FOR REST OF TONIGHT. MODELS SHOW
INCREASING UPWARD MOTION INTO THE WRN ZONES AS A STRONGER SHORTWAVE
TROUGH CURRENTLY OVER THE NW GULF MOVES TOWARD OUR WRN ZONES BY
SAT MORNING. IN THE LOW LEVELS...EXPECT THE HIGH TO OUR N TO SHIFT
EWD ENHANCING ADVECTION OF ATLC MOISTURE TO THE AREA WITH EMBEDDED
SHOWERS POSSIBLE ALONG THE COAST DUE TO COASTAL CONVERGENCE.
TEMPS ARE ON TRACK WITH ONLY SLIGHT ADJUSTMENTS DOWNWARD ABOUT A
DEG ANTICIPATED BUT THEY WILL REMAIN FAIRLY STEADY DUE TO ABUNDANT
CLOUD COVER. WARM TEMPS ALOFT SUGGESTS ONLY RAIN IN SE GA BUT SOME
CENTRAL GA SITES HAVE REPORTED SLEET. MINOR CHANGES WERE MADE TO
POPS TO INCREASE OVER SE GA.
&&
.AVIATION...FOR THERE TO BE SUCH COMPLEXITY IN THE FORECAST WITH
WARM FRONT DEVELOPING SOUGH OF THE AREA ALONG WITH INCREASING
MOISTURE AND UPPER LEVEL ENERGY...TERMINALS HAVE BEEN WELL BEHAVED
AND FORECAST IS FAIRLY STRAIGHTFORWARD. CIGS WILL CONTINUE TO
LOWER TONIGHT FROM SOUTH TO NORTH AND CONFIDENCE IS HIGH WE WILL
SEE MVFR CONDITIONS FOR THE FLORIDA TERMINALS BY 12Z. A CONTINUED
DOWNWARD TREND IS EXPECTED THROUGH SAT WITH IFR CIGS AND MVFR VSBY
DEVELOPING IN MODERATE RA.UNCERTAINTY IN THE FORECAST SURROUNDS
WHETHER CIGS WILL MAKE IT TO THE LIFR CAT BY LATE IN THE TAF
CYCLE. HAVE LEFT IFR FOR NOW BUT WILL NEED TO BE RE EVALUATED BY
LATER SHIFTS.
&&
.MARINE...NEARSHORE BUOYS SHOWING 20 KNOTS SUSTAINED AT THIS HOUR
IN INCREASINGLY CONVERGENT FLOW ALONG THE COAST. OFFSHORE BUOYS
NOT QUITE FEELING THE STRONGEST GRADIENT YET AND ONLY IN THE SCEC
RANGE. AGREE WITH PREVIOUS FORECASTER IN A GRADUAL RAMPING UP OF
THE WIND SPEEDS DURING THE OVERNIGHT PERIOD WITH SCA FOR ALL
WATERS ADVERTISED. ONLY CHANGE TO THE COASTALS WILL BE TO INDICATE
MORE OF A TREND IN THE OFFSHORE PORTION FOR THE INCREASE IN WINDS
AND SEAS TONIGHT. REMAINDER OF THE FORECAST IS ON TRACK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 37 53 49 70 / 30 90 80 60
SSI 45 60 58 73 / 40 100 90 50
JAX 43 64 60 77 / 40 80 70 50
SGJ 52 68 65 78 / 50 80 60 40
GNV 44 69 60 79 / 50 60 50 30
OCF 48 72 63 81 / 50 60 40 30
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...FLOOD WATCH FROM 4 AM EST SATURDAY THROUGH SUNDAY AFTERNOON FOR
APPLING-BACON-COFFEE-JEFF DAVIS-WAYNE.
AM...SMALL CRAFT ADVISORY UNTIL 7 AM EST SUNDAY FOR ALTAMAHA SOUND GA
TO FERNANDINA BEACH FL 20 NM TO 60 NM OFFSHORE-FERNANDINA
BEACH TO ST AUGUSTINE FL 20 NM TO 60 NM OFFSHORE-ST
AUGUSTINE TO FLAGLER BEACH FL 20 NM TO 60 NM OFFSHORE.
SMALL CRAFT ADVISORY UNTIL 10 PM EST SATURDAY FOR ALTAMAHA SOUND
GA TO FERNANDINA BEACH FL OUT 20 NM-FERNANDINA BEACH TO ST
AUGUSTINE FL OUT 20 NM-ST AUGUSTINE TO FLAGLER BEACH FL OUT
20 NM.
&&
$$
SHASHY/DEESE/PRESNALL
