FXUS62 KJAX 150054 AFDJAX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 854 PM EDT SAT APR 14 2007 ...TORNADO WATCH IN EFFECT FOR WESTERN GA COUNTIES... ...STRONG TO SEVERE THUNDERSTORMS LATE TONIGHT INTO SUNDAY MORNING... .SHORT TERM...INFLUX OF MOISTURE FROM THE EAST COAST SEABREEZE COMBINED WITH WARM FRONT WHICH STRETCHES FROM CENTRAL GEORGIA THROUGH THE COASTAL GEORGIA REGION WAS JUST ENOUGH TO PRODUCE SOME SHOWERS AND ISOLATED THUNDERSTORMS OVER THE AREA. LOW LEVEL CAPE HAS BEEN LACKING DURING THE EVENING HOURS AND UPDRAFT STRENGTH HAS BEEN INSUFFICIENT TO OVERCOME DRY AIR ABOVE 600 MB DEPICTED BY THE MODELS. AS A RESULT...ACTIVITY HAS BEEN VERY BENIGN WITH BARELY ANY LIGHTNING TO SPEAK OF...YET. AS THE EVENING PROGRESSES...MODELS IN AGREEMENT IN MOISTURE AT ALL LEVELS INCREASING AND MORE ROBUST UPDRAFTS LIKELY AHEAD OF THE MAIN LINE. AS FOR THE MAIN LINE...NEARLY CONTINUOUS LINE OF SHOWERS AND THUNDERSTORMS EXTENDS THROUGH THE PANHANDLE MAKING STEADY PROGRESS EASTWARD. RUC SHORT TERM FORECAST HAS THE LINE ARRIVING NEAR THE WESTERN ZONES BY 06Z AND WELL INTO THE FORECAST AREA BY 09Z. HOWEVER...LOOKING AT RADARS TO THE WEST OF HERE...SEE IMPRESSIVE REAR INFLOW JETS ALLOWING MORE OF AN EASTWARD MOVEMENT TO THE STRONGER STORMS AND WILL PERHAPS ALLOW THE ACTIVITY TO ARRIVE EARLIER THAN MODEL PROJECTIONS. WHEN IT DOES ARRIVE...INSTABILITY WILL REMAIN THE BIG QUESTION MARK. SURFACE DEWPOINTS HAVE INCREASED TO THE UPPER 60S TO AROUND 70 OVER THE GEORGIA PORTION WITH LAPSE RATES ABOVE THE SURFACE REMAINING WEAK. RUC USES 70/69 FOR ITS SURFACE DATA WHICH SEEMS REASONABLE AND THIS WOULD ONLY RESULT IN CAPES OF 200-400 J/KG SURFACE BASED. LIFTING ABOVE THIS YIELDS SLIGHTLY HIGHER BUT SIMILAR RESULTS. 0-3KM HELICITY INCREASE TO OVER 300 BY 06Z-09Z WHICH WILL LIKELY REQUIRE A MORE VIGOROUS UPDRAFT TO SUPPORT WIDESPREAD SEVERE. THEREFORE...FEEL THE POTENTIAL IS STILL THERE FOR STRONG TO SEVERE STORMS WITH ISOLATED TORNADOES POSSIBLE...BUT WILL NEED TO SEE MORE UNSTABLE CONDITIONS ALOFT THAN WHAT MODELS ARE INDICATING. NO CHANGES TO CURRENT GRID SET UNTIL NEW WATCHES ARE ISSUED. && .AVIATION...AS MENTIONED ABOVE...TIMING OF THE SQUALL LINE LOOKS TO BE 09Z FOR THE EASTERN MOST TAF SITES AND HAVE CARRIED A TEMPO GROUP THROUGH 13Z WITH GUSTS TO 40 KNOTS POSSIBLE. THERE WILL BE SOME POST FRONTAL MVFR CIGS THROUGH 17Z WITH VFR CONDITIONS EXPECTED THEREAFTER. BOSTON TECHNIQUE INDICATING GUSTS TO 35 KNOTS POSSIBLE SUN AFTERNOON AND HAVE INCLUDED WITH THE 00Z ISSUANCE. && .MARINE...CURRENT FORECAST WITH SCA FOR THE REMAINDER OF TONIGHT LOOKS ON TRACK AND FORECAST GRIDS MATCH BUOY OBS WELL. NO CHANGES PLANNED. && .PRELIMINARY POINT TEMPS/POPS... AMG 62 64 39 70 / 60 10 0 0 SSI 69 70 47 69 / 60 60 0 0 JAX 65 70 40 73 / 60 60 0 0 SGJ 68 75 47 71 / 60 60 0 0 GNV 65 73 42 74 / 60 50 0 0 OCF 66 74 40 74 / 60 60 0 0 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING FOR FLAGLER-MARION-PUTNAM-ST JOHNS. WIND ADVISORY FROM 12 PM TO 8 PM EDT SUNDAY FOR ALACHUA-BAKER- BRADFORD-CLAY-COLUMBIA-DUVAL-FLAGLER-GILCHRIST-HAMILTON- MARION-NASSAU-PUTNAM-ST JOHNS-SUWANNEE-UNION. FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR ALACHUA-BAKER-BRADFORD-CLAY-COLUMBIA-DUVAL-FLAGLER- GILCHRIST-HAMILTON-MARION-NASSAU-PUTNAM-ST JOHNS-SUWANNEE- UNION. RED FLAG WARNING FROM 2 PM TO 8 PM EDT SUNDAY FOR ALACHUA-BAKER- BRADFORD-CLAY-COLUMBIA-DUVAL-GILCHRIST-HAMILTON-NASSAU- SUWANNEE-UNION. GA...FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING FOR APPLING-ATKINSON-BACON-BRANTLEY-CHARLTON-CLINCH-COASTAL CAMDEN-COASTAL GLYNN-COFFEE-ECHOLS-INLAND CAMDEN-INLAND GLYNN-JEFF DAVIS-PIERCE-WARE-WAYNE. WIND ADVISORY FROM 12 PM TO 8 PM EDT SUNDAY FOR APPLING-ATKINSON- BACON-BRANTLEY-CHARLTON-CLINCH-COASTAL CAMDEN-COASTAL GLYNN- COFFEE-ECHOLS-INLAND CAMDEN-INLAND GLYNN-JEFF DAVIS-PIERCE- WARE-WAYNE. AM...SMALL CRAFT ADVISORY UNTIL 2 PM EDT 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. GALE WARNING FROM 2 PM SUNDAY TO 10 AM EDT 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- ST AUGUSTINE TO FLAGLER BEACH FL 20 NM TO 60 NM OFFSHORE. SMALL CRAFT ADVISORY UNTIL 10 AM EDT 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. && $$ DEESE/SHASHY/KEEGAN