000 FXUS62 KJAX 222000 AFDJAX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 250 PM EST SUN NOV 22 2009 ...LOW CHANCE OF ISOLATED STRONG STORMS THIS AFTN... .SYNOPSIS...AN OCCLUDED SFC LOW JUST SOUTH OF MOBILE BAY WAS SHIFTING SLOWLY EASTWARD AS THE PARENT UPPER LEVEL VORTEX CONTINUED TO BEGIN DISPLACED FROM THE LOW LEVEL CIRCULATION AS IT TRACKED NWD ACROSS THE MID-APPALACHIANS. LOCALLY A HIGH PRESSURE WEDGE ACROSS OUR N GA ZONES WAS SLOWLY YIELDING TO A NORTHWARD ADVANCING WARM FRONT WHICH EXTENDED ROUGHLY FROM COASTAL SE GA WESTWARD TOWARD VLD. CELLS BEGAN TO ROTATE ALONG THE LEADING EDGE OF THE WARM FRONT ACROSS WARE...CHARLTON AND BRANTLEY COUNTIES...BUT LOW LEVELS REMAIN VERY STABLE SO CIRCULATIONS WILL LIKELY REMAIN ELEVATED. SOUTH OF THE WARM FRONT ACROSS N FL A DRY SLOT WAS EDGING EASTWARD ACROSS THE SUWANNEE RIVER VALLEY WHILE A SWATCH OF LIGHT/MODERATE RAIN WAS SHIFTING EAST FROM SGJ-GNV WITH A FEW WEAK TS EMBEDDED OVER MARION COUNTY. .SHORT TERM...TONIGHT THROUGH WED... STILL NOT CONVINCED THAT SVR WEATHER THREAT IS OVER FOR OUR CWA. ALTHOUGH MID/UPR LEVEL DRY SLOT IS EDGING EASTWARD ACROSS NORTH FL...INCREASED INSOLATION AND HIGH SFC BASED INSTABILITIES NEAR THE WARM FRONT IN CONCERT WITH WEAK LOW/MID LEVEL PVA ARE STILL SUFFICIENT ENOUGH TO CONTINUE A LOW TORNADO THREAT THROUGH LATE AFTN ACROSS N FL AND S GA. AS THE BROAD SFC LOW APPROACHES TONIGHT LOW LEVEL WINDS DECOUPLE...LOW LEVEL MOISTURE REMAINS HIGH AND MID/UPR LEVEL SUBSIDENCE INCREASES. THESE CONDITIONS ARE FAVORABLE FOR AREAS OF FOG WITH PATCHY TO AREAS OF DENSE FOG POSSIBLE. STILL NOT GOING TO GO WIDESPREAD DENSE FOG AS MOST GUIDANCE INDICATES DUE TO PRESENCE OF LINGERING LOW CLOUDS...BUT AS DEW PT DEPRESSIONS DECREASE TONIGHT WE COULD SEE LOW CIGS LOWER TOWARD THE SFC. MINS TONIGHT WILL RANGE FROM NEAR 50 NORTH TO NEAR 70 ALONG OUR SE FL COAST. MON EXPECT DRY AND MOSTLY TO PARTLY CLOUDY SKIES AS LOW PRESSURE RE-DEVELOPS OFFSHORE OF THE SE ATLANTIC COAST AND ANOTHER HIGH PRESSURE WEDGE WORKS IT WAY DOWN THE APPALACHIANS OVER N GA. NNW FLOW WILL VEER NNE MON NIGHT WITH AREAS OF FOG LIKELY ONCE AGAIN AS MINS DROP INTO THE UPPER 40S ACROSS OUR NORTHERN ZONES TO NEAR 60S SOUTH. TUE & WED...THE COASTAL TROUGH OFFSHORE AMPLIFIES AS AN APPROACHING BUT WEAKENING SFC FRONTAL ZONE NEARS AS A STRONG UPPER LEVEL TROUGH SWEEPS ACROSS THE PLAINS. THIS TROUGH IS PROGGED TO DEVELOP A SFC LOW IN THE GULF THAT WILL LIKELY TRACK ACROSS THE FL PENINSULA AND/OR RE-DEVELOP OFFSHORE OF THE FL EAST COAST WED NIGHT INTO THU. INCREASING ISENTROPIC LIFT...ESPECIALLY ACROSS OUR FL ZONES...WILL RAISE RAIN CHANCES LATE TUE THROUGH EARLY THU. WILL CONTINUE WITH THE HIGHEST POPS FROM SGJ-GNV SOUTHWARD. MINS WILL RANGE FROM THE 40S SE GA TO 60S SE FL ZONES...WITH MAXES NEAR 70 TO MID 70S UNDER MOSTLY TO PARTLY CLOUDY SKIES. .LONG TERM...THU THROUGH SUN... A DEEP UPPER LEVEL TROUGH...AN APPROACHING WEAK SFC FRONT AND THE INVERTED TROUGH OFFSHORE OF THE SE ATLANTIC COAST WILL PROGRESS DOWNSTREAM OF THE REGION LATE THU. THIS WILL LOWER RAIN CHANCES FRI AS DRY AIR FILTERS OVER THE AREA...BUT SKIES MAY REMAIN PARTLY CLOUDY UNTIL SFC RIDGE BUILDS OVER THE CWA FROM THE GULF COAST THIS WEEKEND. STRONG COLD AIR ADVECTION WILL BEGIN OVER THE CWA FRI WITH TEMPS FALLING BELOW CLIMO VALUES FOR THE WEEKEND. EXPECT MINS IN THE 30S WELL INLAND/40S COAST WITH MAXES IN THE 60S UNDER MOSTLY CLEAR SKIES SAT AND SUN. && .AVIATION...VFR CONDITIONS ARE DOMINATING THE NE FL TERMINALS...WITH MVFR CEILINGS AT KSSI TERMINAL DUE TO CLOSE PROXIMITY TO WARM FRONTAL BOUNDARY. LITTLE CHANGE IS IS EXPECTED THROUGH AROUND 02Z...WITH LOWERING CEILINGS FORECAST OVERNIGHT WITH PASSAGE OF WEAK LOW PRESSURE AND ATTENDANT COLD FRONT. IN FACT...THE COMBINATION OF COOLING TEMPERATURES AND ELEVATED MOISTURE WILL LIKELY YIELD FOG OVERNIGHT...WITH THE POTENTIAL FOR DENSE FOG DEVELOPMENT. && .MARINE...LOW PRESSURE CENTER IS FORECAST TO CROSS THE LOCAL WATERS TONIGHT...WITH SOUTHERLY FLOW REGIME LIKELY TO DOMINATE. THUS...WILL RECOMBINE FL/GA ZONES...BUT WILL CONTINUE TO SEGMENT THE NEARSHORE/ OFFSHORE ZONES. SOUTHERLY WINDS WILL LIKELY SUSTAIN AROUND 10 KNOTS ACROSS THE NEARSHORE LEGS TONIGHT...AND CLOSER TO 15 KNOTS FOR THE OFFSHORE LEGS. SEAS WILL REMAIN ELEVATED THROUGH MONDAY DUE TO LINGERING SWELLS. && .PRELIMINARY POINT TEMPS/POPS... AMG 50 67 48 67 / 30 0 0 0 SSI 58 71 54 66 / 40 0 0 10 JAX 59 75 54 70 / 40 10 10 20 SGJ 64 76 60 69 / 40 10 10 30 GNV 60 76 55 72 / 30 10 10 20 OCF 61 78 57 75 / 30 10 10 20 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && $$ ENYEDI/ZAPPE/WALKER