FXUS62 KJAX 161924 AFDJAX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 224 PM EST FRI JAN 16 2009 .SHORT TERM...PICTURE PERFECT DAY IS MARRED ONLY BY COOL TEMPS AND BRISK WINDS WHICH ARE GUSTING TO NEAR 25 MPH OVER CSTL ZONES. MARINE STRATO-CU DECK IS IMPINGING ON THE COAST OF NE FL AND WILL CONTINUE TO MOVE SOUTH THRU THE EVENING. BENEATH THIS LAYER THE ATMOSPHERE IS VERY DRY AND NOT EXPECTING ANY TYPE OF PRECIP. WILL KEEP PARTLY CLOUDY SKIES FOR SERN TWO COUNTIES THEN CLEARING AFTER MIDNIGHT. ELSEWHERE CLEAR SKIES PROGGED FOR TONIGHT WITH A SURFACE HIGH TO OUR NORTH PROVIDING EXCELLENT RADIATIONAL COOLING CONDS. DEWPOINTS WILL BE IN SINGLE DIGITS AND TEENS ACRS SE GA...TEENS IN SUWANNEE VALLEY AND LOW 20S REST OF NE FL. NE TO NLY WINDS NEAR 5 MPH WILL PRODUCE WIND CHILLS IN TEENS NW PORTION AND 20S SE PORTION BUT WILL NOT MEET THE 10 MPH NECESSARY FOR AN ADVISORY. MINS HAVE BEEN RUNNING ABOVE MOS GUIDANCE. HAVE DECIDED TO RAISE MIN TEMPS TO BE MORE IN LINE WITH THE ENSEMBLE MEAN WHICH IS A HAS BEEN SLIGHTLY HIGHER THAN MOS. THIS MOVES THE LINE BETWEEN A FREEZE AND HARD FREEZE A LITTLE TO THE NW AND REMOVES MARION CO FROM THE HARD FRZ...ALSO AREAS ALONG THE ST JOHNS RIVER...ALTHOUGH IT DOES CATCH THE WRN PORTION OF THESE COUNTIES. THE COLD HIGH WILL MIGRATE EWD OVER THE WEEKEND WITH NELY FLOW SATURDAY BRINGING INCREASED MOISTURE TO ERN PORTION...THEN SHIFTING TO SLY FLOW SUNDAY IN ADVANCE OF NEXT COLD FRONT. TEMPS WILL REMAIN UNSEASONABLY COOL AND TEMPS NEAR 30 ARE EXPECTED AGAIN SAT NIGHT. A SLIGHT WARMUP COMES SUNDAY WHEN TEMPS REACH THE 60S ALTHOUGH NW PORTION CAN EXPECT SCT SHOWERS IN THE AFTN. THE FRONT MOVES THRU SUN NIGHT ACCOMPANIED BY A BAND OF SCT SHOWERS MOVING SOUTHEASTWARD AND CLEARING OUT MONDAY MORN BRINGING A RETURN OF UNSEASONABLY COOL AIR. UPPER SHORTWAVE WITH A WRAP-AROUND CLOUDS WILL LIKELY BRING CONSIDERABLE CLOUDS TO THE AREA LATE MON. .LONG TERM...A CHANGE IN THE LONG WAVE PATTERN IS EXPECTED MID WEEK. ANOTHER COLD FRONT WILL PASS BY ON TUE WITH SFC HIGH BUILDING IN FROM THE WEST. THE RIDGE DOMINATING THE WRN U.S. WILL PUSH EWD INTO THE LOCAL AREA LATE IN THE WEEK. FREEZING TEMPS ARE LIKELY INLAND EACH NIGHT AS TEMPS WILL REMAIN BELOW CLIMO. && .AVIATION...ALTHOUGH STRATO-CU DECK OVER THE ATLANTIC HAS BEEN INCREASING IN AREAL COVERAGE AND ENCROACHING ON THE COASTAL TAF SITES...WORST CASE SCENARIO HAS BRIEF BKN CONDITIONS AT CRG IN THE MVFR RANGE. OTHERWISE...A DRAINAGE FLOW DEVELOPING WILL LEAD TO VFR CONDITIONS BEGINNING TONIGHT. && .MARINE...WITH STRONG HIGH PRESSURE REMAINING WELL TO THE NORTH AT THIS HOUR...GRADIENT REMAINS QUITE STRONG OVER THE MARINE ENVIRONMENT WITH SCA CONDITIONS AT ALL AREA BUOYS. HIGH WILL SHIFT TO THE MID ATLANTIC TONIGHT...BUT COLD AIR ADVECTION REGIME COMBINED WITH CONTINUED GRADIENT WILL KEEP SCA FOR THE NEARSHORE PORTION THROUGH THIS EVENING AND OFFSHORE ZONES THROUGH SAT EVENING DUE TO RESIDUAL HIGH SEAS. HIGH PRESSURE WILL THEN BUILD SLOWLY SOUTH AND ALLOW FOR A BRIEF PERIOD OF MORE TRANQUIL CONDITIONS THROUGH EARLY SUNDAY AFTERNOON. NEXT STRONG SHORTWAVE WITH ATTENDANT COLD FRONT WILL SWEEP THROUGH THE DEEP SOUTH WITH FLOW AHEAD OF THE SYSTEM INCREASINGLY STRONG AMONG THE MODEL MEMBERS AND GOOD AGREEMENT IN DEPICTING SUSTAINED 25 KNOT WINDS FOR THE OFFSHORE PORTION. && .FIRE WEATHER...DEVELOPING ONSHORE FLOW ALONG THE COASTAL COUNTIES ALONG WITH RAPIDLY DEVELOPING CU DECK HAS ALLOWED FOR A DRAMATIC INCREASE IN ATLANTIC ZONE DEWPOINTS. WE ARE NOW AT 28 HERE AT JIA AFTER STARTING OUT IN THE SINGLE DIGITS THIS MORNING. THIS WILL LIKELY KEEP MANY AREAS ALONG AND EAST OF THE I95 CORRIDOR FROM REACHING RED FLAG STATUS BUT WILL LET IT RIDE AT THIS POINT GIVEN THE DRIER CONDITIONS OVER THE WESTERN PORTIONS OF THESE COUNTIES. ALTHOUGH ONSHORE FLOW WILL NOT BE QUITE AS PRONOUNCED ON SATURDAY...LIGHTER WINDS AND LESS MIXING WILL RESULT IN A SLOW DECLINE IN RH VALUES. STILL FEEL RED FLAG WILL BE REALIZED OVER THE SUWANNEE VALLEY AND HAVE UPGRADED THOSE AREAS WITH THE AFTERNOON PACKAGE. && .PRELIMINARY POINT TEMPS/POPS... AMG 22 51 28 61 / 0 0 0 30 SSI 29 49 35 61 / 0 0 0 10 JAX 27 53 32 66 / 0 0 0 10 SGJ 36 54 37 65 / 10 0 0 10 GNV 27 58 31 67 / 0 0 0 10 OCF 28 60 34 68 / 0 0 0 10 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...HARD FREEZE WARNING FROM 9 PM THIS EVENING TO 10 AM EST SATURDAY FOR BAKER-COLUMBIA-GILCHRIST-HAMILTON-SUWANNEE-UNION. HARD FREEZE WARNING FROM 11 PM THIS EVENING TO 10 AM EST SATURDAY FOR ALACHUA-BRADFORD-CLAY-DUVAL-MARION-NASSAU- PUTNAM. FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EST SATURDAY FOR FLAGLER-ST JOHNS. RED FLAG WARNING UNTIL 6 PM EST THIS AFTERNOON FOR CLAY-DUVAL- NASSAU-PUTNAM. RED FLAG WARNING UNTIL 7 PM EST THIS EVENING FOR ALACHUA-BAKER- BRADFORD-COLUMBIA-GILCHRIST-HAMILTON-MARION-SUWANNEE-UNION. RED FLAG WARNING FROM 11 AM TO 6 PM EST SATURDAY FOR ALACHUA- BAKER-BRADFORD-COLUMBIA-GILCHRIST-HAMILTON-SUWANNEE-UNION. FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING FOR ALACHUA-BAKER-BRADFORD-COLUMBIA-GILCHRIST-HAMILTON-SUWANNEE- UNION. RED FLAG WARNING UNTIL 4 PM EST THIS AFTERNOON FOR ST JOHNS. FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING FOR CLAY-DUVAL-NASSAU. RED FLAG WARNING FROM 12 PM TO 5 PM EST SATURDAY FOR MARION. GA...HARD FREEZE WARNING FROM 9 PM THIS EVENING TO 10 AM EST SATURDAY FOR APPLING-ATKINSON-BACON-BRANTLEY-CHARLTON-CLINCH-COFFEE- ECHOLS-JEFF DAVIS-PIERCE-WARE-WAYNE. HARD FREEZE WARNING FROM 11 PM THIS EVENING TO 10 AM EST SATURDAY FOR COASTAL CAMDEN-COASTAL GLYNN-INLAND CAMDEN- INLAND GLYNN. AM...SMALL CRAFT ADVISORY UNTIL 10 PM EST SATURDAY 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 11 PM EST THIS EVENING 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. && $$ TRABERT/DEESE/KEEGAN