FXUS62 KJAX 160228 AFDJAX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 930 PM EST SAT DEC 15 2007 ...SLIGHT RISK OF SEVERE TSTMS CONTINUES OVERNIGHT... .SHORT TERM...PRE-FRONTAL SQUALL LINE CONTINUES TO MAKE ITS WAY ACROSS THE FL PANHANDLE AND E GOMEX. WARM FRONT HAS LIFTED N OF OUR COUNTY WARNING AREA (CWA) WITH DEW POINTS IN THE UPPER 60S AND LOWER 70S ACROSS THE AREA. SFC BASED CAPES HAVE DROPPED OFF TO AROUND 500 J/KG BUT BEST CAPES SHOULD STILL BE RUNNING CLOSE TO 1000 J/KG... PARTICULARLY OVER NE FL. MOST OF THE LIGHTNING STRIKES OVER THE LAST COUPLE OF HOURS HAVE BEEN OVER THE GOMEX AND WITHIN ABOUT 50 MI OF THE COAST OVER LAND. CLOUD TOPS HAVE WARMED IMMEDIATELY W OF OUR CWA DURING THE PAST COUPLE OF HOURS AS WELL. 850 MB JET IS PROGGED TO INCREASE OVERNIGHT...WITH VALUES OF AROUND 50 KTS LIKELY. IN ADDITION...WARM AIR ADVECTION WILL CONTINUE FROM THE S. WITH SIMILAR PATTERNS...STRONGEST STORMS WOULD LIKELY FOCUS OVER THE SUWANNEE VALLEY AND PERHAPS EXTREME S ZONES OVERNIGHT. HOWEVER...AM CONCERNED THAT THE REMNANT OLGA CIRCULATION WHICH STILL SHOWS UP QUITE PROMINENTLY ON SAT PIX WILL BOTH AID CONVERGENCE ALONG THE PRE-FRONTAL TROF THAT IS ABSORBING IT...AS WELL AS BACK WINDS TO MORE S OR EVEN SSE DIRECTION AHEAD OF THE SQUALL LINE. ALTHO THE GREATEST IMPACT FROM THIS SCENARIO WILL LIKELY AFFECT THE W COAST OF CENTRAL FL...THE 18Z NAM DRAGS AN IMPRESSIVE AREA OF DIFFERENTIAL POSITIVE VORTICITY ADVECTION ACROSS NE FL AND EXTREME SE GA AROUND 09Z TONIGHT...WHICH IS COINCIDENT WITH STRONGEST LOW-LEVEL JET. AS A RESULT...MAY SEE THE SQUALL LINE INTENSIFY OVER THE AREA LATER TONIGHT. WILL ALSO CONTINUE TO MONITOR ANY ISOLD FAST MOVING CONVECTION FROM THE S. FOR THE UPDATE...NOT PLANNING MUCH IN THE WAY OF CHANGES TO THE TEXT ZFP. HOWEVER...WILL LIKELY ADJUST TEMP CURVE TO MATCH MOS GUIDANCE SINCE THE COLD FRONT WILL BE ENTERING OUR W ZONES LATE TONIGHT. && .AVIATION...PRE-FRONTAL LINE OF SHOWERS AND THUNDERSTORMS WILL MOVE THROUGH SOMETIME DURING THE 06Z-10Z TIME FRAME AND HAVE MENTION OF TEMPO IFR CONDITIONS FROM THUNDERSTORMS AND WIND GUSTS TO 30 KNOTS. WILL LIKELY SEE PREVAILING MVFR CONDITIONS FROM REDUCED VSBY/CIGS AND LOW LEVEL WIND SHEAR FROM STRONG SOUTHERLY LOW LEVEL JET AFTER 06Z AS WELL. COLD FRONT PROGGED TO MOVE THROUGH AROUND 12Z SUN WITH WINDS SHIFTING TO NW WITH GUSTS TO 25 KNOTS BEHIND FRONT. && .MARINE...ARE ALREADY SEEING ADVISORY CONDITIONS OFFSHORE. PRE-FRONTAL SQUALL LINE MOVING OFFSHORE EARLY SUNDAY FOLLOWED BY COLD FRONTAL PASSAGE SUNDAY MORNING. && .JAX WATCHES/WARNINGS/ADVISORIES... FL...FREEZE WATCH FROM LATE SUN NIGHT THRU MON MORNING FOR ALACHUA-BAKER-BRADFORD-COLUMBIA-GILCHRIST-HAMILTON-MARION- SUWANNEE-UNION. FREEZE WATCH FROM LATE SUN NIGHT THRU MON MORNING FOR CLAY-DUVAL-NASSAU-PUTNAM. FIRE WEATHER WATCH FROM MON MORNING THRU MON AFTERNOON FOR ALACHUA-BAKER-BRADFORD-CLAY-COLUMBIA-DUVAL-FLAGLER- GILCHRIST-HAMILTON-MARION-NASSAU-PUTNAM-ST JOHNS-SUWANNEE- UNION. GA...FREEZE WATCH FROM LATE SUN NIGHT THRU MON MORNING FOR APPLING-ATKINSON-BACON-BRANTLEY-CHARLTON-CLINCH-COFFEE- ECHOLS-JEFF DAVIS-PIERCE-WARE-WAYNE. FIRE WEATHER WATCH MON 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 SUN NIGHT THRU MON MORNING FOR INLAND CAMDEN-INLAND GLYNN. AM...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 7 PM MON FOR ST AUGUSTINE TO FLAGLER BEACH FL 20 NM TO 60 NM OFFSHORE. SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 12 PM MON FOR ALTAMAHA SOUND GA TO ST AUGUSTINE FL 20 NM TO 60 NM OFFSHORE. SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 8 AM MON FOR ALTAMAHA SOUND GA TO FLAGLER BEACH FL OUT 20 NM. && $$ CARROLL/PETERSON/DEESE/WALKER