FXUS62 KJAX 160653 AFDJAX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 153 AM EST SUN DEC 16 2007 ...TORNADO WATCH IN EFFECT THROUGH 6 AM THIS MORNING... ...MUCH COLDER AIR WILL FILTER OVER THE AREA TODAY... .SYNOPSIS...AN EXTENSIVE LINE OF PRE-FRONTAL PRECIP IS MAKING ITS WAY THROUGH OUR CWA TONIGHT WITH A BROAD AREA OF HEAVY RAIN ACROSS SE GA WITH A FEW ISOLD TS...WHILE THE STRONGER STORMS EXIST OVER OUR FL ZONES WHERE GOMEX INSTABILITY HAS ADVECTED INLAND. POTENTIAL STILL EXISTS FOR A FEW ISOLD SVR STORMS WITH THE MAIN CONCERNS BEING DAMAGING WIND GUSTS AND POSSIBLY AN ISOLATED TORNADO. THE LEADING EDGE OF THE ACTUAL COLD FRONT IS NOW MAKING ITS WAY THROUGH THE CENTRAL FL PANHANDLE AND SHOULD PRESS THROUGH OUR AREA THIS MORNING AFTER DAYBREAK WHICH ONLY A THIN LINE OF SHRA POSSIBLE. .SHORT TERM...TODAY THROUGH TUE... MUCH COLDER AIR WILL FILTER OVER THE AREA TODAY AS A STRONG SURFACE HIGH BUILDS OVER OUR THE GULF COAST STATES. TEMPS BELOW CLIMO ARE EXPECTED THROUGH TUESDAY AS THE RIDGE SHIFTS EAST THROUGH PERIOD. TODAY...FOLLOWING THE PASSAGE OF THE PRE-FRONTAL SQUALL LINE EARLY THIS MORNING STRONG COLD AND DRY AIR ADVECTION WILL FILTER OVER THE AREA. BOSTON TECHNIQUE SUPPORTS WIND GUSTS ACROSS MUCH OF THE AREA TO 30 KTS WHICH WILL NOT ONLY SUPPORT A LAKE WIND ADVISORY FOR ALL ZONES TODAY BUT ALSO HELP TO ERODE LOW STRATUS WHICH IS TRAILING THE SURFACE FRONT. EXPECT PARTLY CLOUDY TO MOSTLY CLEAR SKIES ACROSS THE ENTIRE CWA THIS AFTN. MAX TEMPS WILL LIKELY BE REALIZED EARLY THIS MORNING BEFORE SUNRISE...THEN FALL THROUGH THE DAY INTO THE MID 50S GA TO LOWER 60S FL. TONIGHT...PRESSURE GRADIENT WILL REMAIN TIGHT ENOUGH TO KEEP LOW LEVELS MIXED ENOUGH TO PREVENT FROST TONIGHT DESPITE A WIDESPREAD FREEZE INLAND. HAVE UPGRADED THE FREEZE WATCH TO A WARNING ALL INLAND ZONES. SFC SPEEDS AROUND 5-10 MPH WILL MAKE FOR WIND CHILLS IN THE LOW TO MID 20S BY DAYBREAK...BUT A WIND CHILL ADVISORY IS NOT ANTICIPATED ATT SINCE THE LIGHTEST SPEEDS ARE EXPECTED AROUND THE TIME OF MIN TEMPS. MON & MON NIGHT...AN UNSEASONABLY COLD DAY MON WITH MAXES ONLY TOPPING OUT IN THE LOW TO MID 50S...ABOUT 10 DEG BELOW CLIMO FOR THIS TIME OF YEAR. MON NIGHT ANOTHER WIDESPREAD FREEZE INLAND AS THE SURFACE HIGH BUILDS OVER THE AREA BRINGING IDEAL RADIATIONAL COOLING CONDITIONS AND PROMOTING AREAS OF FROST DEVELOP ACROSS OUR NORTHERN INLAND ZONES BY DAYBREAK. HAVE HOISTED A FREEZE WATCH FOR ALL INLAND AREAS MON NIGHT...AND PARTS OF OUR INLAND SE GA AND THE N SUWANNEE VALLEY IN FL MAY EVEN SEE A WIDESPREAD HARD FREEZE. TUE & TUE NIGHT...THE SFC RIDGE WILL BEGIN TO BUILD OFFSHORE OF THE ATLANTIC COAST WITH A LOW LEVEL ENE FLOW DEVELOPING LOCALLY WHICH WILL MODERATE TEMPS WITH MAXES NEAR 60 AND BEGIN TO ADVECT A THICK BANK OF COASTAL STRATOCU ONSHORE ACROSS OUR FL ZONES. MAY SEE A LIGHT COASTAL SPRINKLE INTO TUE NIGHT BUT HAVE CAPPED POPS AT 10%. .LONG TERM...WED THROUGH SAT... THE SFC HIGH WILL CONTINUE TO BUILD OFFSHORE AND WEDGE DOWN THE APPALACHIANS WHILE COASTAL TROUGHING WILL LIKELY DEVELOP JUST OFFSHORE OF OUR ATLANTIC COAST. COASTAL CLOUDS AND LIGHT SPRINKLES WILL BE POSSIBLE THROUGH THU...THEN A WEAK SFC FRONT APPROACHES AND LOW LEVEL WINDS VEER SSE INTO FRI. A LOW CHANCE OF POPS IS FORECAST FRI AND SAT AS THIS TROUGH BECOMES DIFFUSE ACROSS THE AREA. SUN THE NEXT COLD FRONT WILL NEAR WHICH A LOW CHANCE OF POPS EXPECTED SUN AFTN. TEMPS WILL MODERATE THROUGH THE PERIOD WITH ABOVE NORMAL TEMPS EXPECTED BY THE END OF THE WEEK WITH MAXES IN THE LOWER 70S. && .AVIATION...PRE-FRONTAL LINE OF SHOWERS AND THUNDERSTORMS IS CROSSING THE REGION AND HAVE TEMPO IFR FOR THUNDERSTORMS AND WIND GUSTS TO 30 KNOTS AT ALL TAF SITES. WILL LIKELY SEE PREVAILING MVFR CONDITIONS FROM REDUCED CIGS AND LOW LEVEL WIND SHEAR FROM STRONG SOUTHERLY LOW LEVEL JET OVERNIGHT. COLD FRONT PROGGED TO MOVE THROUGH AROUND 12Z SUN WITH WINDS SHIFTING TO NW WITH GUSTS TO 25 KNOTS BEHIND FRONT. VFR CONDITIONS WILL PREVAIL AFTER FRONT CLEARS AROUND 15Z. && .MARINE...SCA CONDS ARE OCCURRING OVER THE WATERS. ST AUGUSTINE BUOY HAS REPORTED GUSTS TO GALE FORCE. SUCH GUSTS ARE NOT WIDESPREAD AND WILL CONTINUE TO MENTION GUSTS WITHOUT UPGRADING THE SCA. SOUTH WINDS WILL VEER TO WEST BY MID MORN THEN NW IN THE AFTN FOLLOWING FROPA. PRESSURE GRADIENT WEAKENS BY MONDAY NIGHT AS HIGH SETTLES N OF AREA AND WINDS SHIFT TO ONSHORE. ALL HEADLINES SHOULD BE DROPPED BY THAT TIME. && .FIRE WEATHER...MARGINAL RED FLAG CONDS ARE POSSIBLE ACRS THE SUWANNEE VALLEY THIS AFTN AS DEWPOINTS FALL OFF PRECIPITOUSLY AND INCREASING WINDS LEAD TO A SMALL WINDOW FOR RED FLAGS TO BE REALIZED. AT THIS TIME...RH'S APPEAR TO REMAIN ABOVE 35% AND WILL NOT ISSUE A WRNG. A FIRE WEATHER WATCH HAS BEEN ISSUED FOR MONDAY AS DRIER AIR SHOULD MIX TO THE SURFACE ALLOWING SEVERAL HOURS BELOW CRITICAL RH VALUES...ESPECIALLY INLAND NE FL. SE GEORGIA AND COASTAL AREAS MAY NOT REACH THE DURATION REQUIREMENT. && .PRELIMINARY POINT TEMPS/POPS... AMG 57 28 53 26 / 10 0 0 0 SSI 63 34 51 37 / 30 0 0 10 JAX 65 31 52 31 / 30 0 0 0 SGJ 68 34 52 38 / 60 0 10 10 GNV 66 29 54 29 / 20 0 0 0 OCF 67 30 54 30 / 30 0 0 0 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...FREEZE WATCH FROM LATE MONDAY NIGHT THROUGH TUESDAY MORNING FOR ALACHUA-BAKER-BRADFORD-COLUMBIA-GILCHRIST-HAMILTON-MARION- SUWANNEE-UNION. LAKE WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM EST THIS AFTERNOON FOR ALACHUA-BAKER-BRADFORD-CLAY-COLUMBIA-DUVAL- FLAGLER-GILCHRIST-HAMILTON-MARION-NASSAU-PUTNAM-ST JOHNS- SUWANNEE-UNION. FREEZE WARNING FROM 3 AM TO 9 AM EST MONDAY FOR ALACHUA-BAKER- BRADFORD-COLUMBIA-GILCHRIST-HAMILTON-MARION-SUWANNEE-UNION. FREEZE WATCH FROM LATE MONDAY NIGHT THROUGH TUESDAY MORNING FOR CLAY-DUVAL-NASSAU-PUTNAM. FREEZE WARNING FROM 5 AM TO 8 AM EST MONDAY FOR CLAY-DUVAL- NASSAU-PUTNAM. FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY AFTERNOON FOR ALACHUA-BAKER-BRADFORD-CLAY-COLUMBIA-DUVAL-FLAGLER- GILCHRIST-HAMILTON-MARION-NASSAU-PUTNAM-ST JOHNS-SUWANNEE- UNION. GA...FREEZE WATCH FROM LATE MONDAY NIGHT THROUGH TUESDAY MORNING FOR APPLING-ATKINSON-BACON-BRANTLEY-CHARLTON-CLINCH-COFFEE- ECHOLS-JEFF DAVIS-PIERCE-WARE-WAYNE. LAKE WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM EST THIS AFTERNOON FOR APPLING-ATKINSON-BACON-BRANTLEY-CHARLTON- CLINCH-COASTAL CAMDEN-COASTAL GLYNN-COFFEE-ECHOLS-INLAND CAMDEN-INLAND GLYNN-JEFF DAVIS-PIERCE-WARE-WAYNE. FREEZE WARNING FROM 3 AM TO 9 AM EST MONDAY FOR APPLING-ATKINSON- BACON-BRANTLEY-CHARLTON-CLINCH-COFFEE-ECHOLS-JEFF DAVIS- PIERCE-WARE-WAYNE. FIRE WEATHER WATCH MONDAY AFTERNOON FOR APPLING-ATKINSON-BACON- BRANTLEY-CHARLTON-CLINCH-COASTAL CAMDEN-COASTAL GLYNN- COFFEE-ECHOLS-INLAND CAMDEN-INLAND GLYNN-JEFF DAVIS-PIERCE- WARE-WAYNE. FREEZE WATCH FROM LATE MONDAY NIGHT THROUGH TUESDAY MORNING FOR INLAND CAMDEN-INLAND GLYNN. FREEZE WARNING FROM 5 AM TO 8 AM EST MONDAY FOR INLAND CAMDEN- INLAND GLYNN. AM...SMALL CRAFT ADVISORY UNTIL 7 PM EST MONDAY FOR ST AUGUSTINE TO FLAGLER BEACH FL 20 NM TO 60 NM OFFSHORE. SMALL CRAFT ADVISORY UNTIL 12 PM EST MONDAY 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. SMALL CRAFT ADVISORY UNTIL 8 AM EST MONDAY 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. && $$ ABE/MKT/SEC/PP/AW