FXUS62 KJAX 111026
AFDJAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
514 AM EST FRI DEC 11 2009
...CHILLY TEMPERATURES TODAY FOLLOWED BY INCREASING RAIN
CHANCES...
...SHORT TERM...TODAY THROUGH SUNDAY
STRONG HIGH PRESSURE WEDGE DOWN THE EAST COAST WILL KEEP THE AREA
ON THE CHILLY SIDE TODAY. TEMPS WILL STRUGGLE TO REACH 50 AWAY
FROM THE COAST...ESPECIALLY ACROSS SOUTHEAST GEORGIA WHERE TEMPS
WILL LIKELY REMAIN STUCK IN THE 40S ALL DAY. THE NAM AND GFS BOTH
SHOW SOME APPRECIABLE LIFT AROUND 700 MB DUE TO STRONG 850 MB
CONVERGENCE OVER NORTHEAST FLORIDA. HAVE A HARD TIME BELIEVING
THAT THIS WILL AMOUNT TO MUCH MEASURABLE PRECIPITATION GIVEN THAT
DEWPOINTS WILL REMAIN IN THE 20S FOR MUCH OF THE DAY. MUCH OF THE
RAIN SHOULD EVAPORATE BY THE TIME IT REACHES THE GROUND BUT A FEW
LIGHT RAIN SHOWERS WILL BE POSSIBLE ACROSS NE FLORIDA TODAY.
RAIN CHANCES WILL INCREASE INTO THE 30 TO 50 PERCENT RANGE
OVERNIGHT. WINDS WILL VEER TO THE NORTHEAST AS HIGH PRESSURE
MOVES TO THE MID-ATLANTIC COAST. A SURFACE TROUGH WILL DEVELOP
JUST OFFSHORE OVER THE ATLANTIC AND COASTAL CONVERGENCE WILL BE
ENHANCED. AT THE SAME TIME...A LOW TO MID LEVEL TROUGH WILL
DEVELOP ALONG THE GULF COAST AND BEGIN TO NOSE INTO THE WESTERN
PARTS THE LOCAL FORECAST AREA. HIGHEST RAIN CHANCES WILL EXIST
ALONG THE NORTHEAST FLORIDA COAST AND EXTEND BACK THROUGH THE
SUWANNEE RIVER VALLEY. RAINFALL AMOUNTS SHOULD REMAIN ON THE LOW
SIDE AS SURFACE MOISTURE ONLY GRADUALLY INCREASES.
FORCING WILL BECOME STRONGER DURING THE DAY ON SATURDAY.
SURFACE CONVERGENCE WILL INCREASE EVEN FURTHER ALONG THE COAST AS
A SURFACE LOW BEGINS TO DEVELOP. LOW TO MID LEVEL CONVERGENCE WILL
BECOME QUITE STRONG ACROSS SE GEORGIA IN RESPONSE TO AN AMPLIFIED
WEST TO EAST TROUGH IN THE 925 TO 850 MB LAYER. FORECAST SOUNDINGS
SHOW SATURATION THROUGH A VERY DEEP LAYER ON SATURDAY. RAINFALL
AMOUNTS WILL BE HELD IN CHECK SOME DUE TO THE RELATIVELY LOW
DEWPOINTS AT THE SURFACE BUT FORCING WILL BE RATHER STRONG SO
WOULD NOT BE SURPRISED TO SEE WIDESPREAD RAINFALL AMOUNTS IN THE
HALF INCH TO INCH RANGE NORTH OF THE INTERSTATE 10 CORRIDOR ON
SATURDAY.
RAIN WILL WIND DOWN FROM SOUTH TO NORTH SATURDAY NIGHT AND A
SECOND BOUT OF RAIN COULD OCCUR SUNDAY MORNING ACROSS SE GEORGIA.
THE NAM AND GFS ARE IN DISAGREEMENT WITH THIS SCENARIO BUT WILL
LEAN TOWARDS THE GFS WITH THIS PACKAGE GIVEN THAT A FAIRLY STRONG
WARM FRONT IS PROGGED TO LIFT NORTH DURING THIS TIMEFRAME. TEMPS
WILL REBOUND INTO THE UPPER 70S TO LOW 80S ACROSS NE FLORIDA.
...LONG TERM...MONDAY THROUGH THURSDAY
THE AREA WILL BE FIRMLY WITHIN THE WARM SECTOR ON MONDAY. TEMPS
WILL TOP OUT IN THE UPPER 70S TO LOW 80S ACROSS MUCH OF THE
FORECAST AREA. RAIN CHANCES WILL INCREASE MONDAY NIGHT INTO
TUESDAY AS A STRONG COLD FRONT APPROACHES. A SQUALL LINE WILL
LIKELY ATTEND THE FRONT TUESDAY AFTERNOON AND STRONG TO SEVERE
THUNDERSTORMS ARE LOOKING MORE AND MORE LIKELY. MUCH COLDER AIR
WILL ADVANCE INTO THE REGION IN THE WAKE OF THE FRONT AND MUCH OF
THE INTERIOR COULD SEE FREEZING TEMPERATURES.
&&
.AVIATION...
VFR CONDITIONS WILL BE THE RULE TODAY WITH DRY AIR IN PLACE...ALBEIT
TEMPORARILY. CEILINGS DECREASE BEGINNING TONIGHT...VERY LIKELY TO
IFR LEVELS OVERNIGHT. VISIBILITIES TONIGHT WILL BE HIGHLY DEPENDENT
ON RAINFALL BUT SHOULD NOT BE TOO LOW AS WINDS WILL STAY HIGH ENOUGH
TO PREVENT FOG FORMATION UNTIL BOUNDARY LAYER SATURATES...WHICH
PROBABLY WON'T BE UNTIL LATER SATURDAY.
&&
.MARINE...
COASTAL TROUGH DEVELOPMENT WILL STRENGTHEN WINDFIELD IN THE COASTAL
WATERS...WITH WINDS STRONG ENOUGH TO JUSTIFY SCA BY TONIGHT AND
CONTINUING SATURDAY. CURRENT RIP CURRENT RISK FOR SATURDAY INCREASES
TO MODERATE DUE TO THE STRENGTHENING ONSHORE FLOW...BUT DEPENDING ON
SWELL CONTRIBUTION...COULD EVEN GO INTO THE HIGH CATEGORY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 48 36 52 48 / 0 30 80 60
SSI 52 47 61 58 / 20 30 80 70
JAX 52 47 64 59 / 20 40 70 70
SGJ 57 55 68 64 / 30 40 70 70
GNV 52 47 68 60 / 30 40 60 50
OCF 55 51 71 62 / 30 40 60 40
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...RED FLAG WARNING FROM 10 AM THIS MORNING TO 5 PM EST THIS
AFTERNOON FOR COLUMBIA-GILCHRIST-HAMILTON-SUWANNEE.
GA...NONE.
AM...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 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.
&&
$$
SHULER/LETRO
