417 
FXUS62 KJAX 141901
AFDJAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
256 PM EDT THU MAR 14 2013

...FROST ADVISORY INLAND TONIGHT...

...CONTINUED DRY WITH A WARM UP THIS WEEKEND...

.SHORT TERM (TONIGHT-SATURDAY NIGHT)...

TONIGHT...COOL HIGH PRESSURE BUILDS IN ACROSS NORTH FL LATE
TONIGHT. WITH MOSTLY CLEAR SKIES...NEAR CALM WIND...AND COOL 
AND DRY AIR IN PLACE...TEMPS EXPECTED TO RAPIDLY FALL OFF
INTO THE LOWER TO MID 30S ACROSS MUCH OF THE INLAND AREAS. 
WITH GOOD RADIATIONAL COOLING AND ELEVATED DEWPOINT TEMPS
STAGE SET FOR FROST ACROSS THE INLAND AREAS AND HAVE POSTED 
A FROST ADVISORY FROM LATE TONIGHT INTO EARLY MONDAY MORNING.

FRIDAY/FRIDAY NIGHT...HIGH PRESSURE BEGINS TO WEAKEN AND 
MOVES ACROSS NORTH CENTRAL FL. LIGHT NW WINDS IN THE MORNING 
BECOME SW AND W IN THE AFTERNOON. SEA BREEZES EXPECTED AT 
BOTH GULF AND ATLANTIC COASTS. AIR MASS MODIFIES AND AFTER 
COLD START...MAX TEMPS REACH THE LOWER 70S INLAND. SEA BREEZE 
KEEPS THE COAST IN THE UPPER 60S. CLEAR SKIES EXPECTED FRIDAY 
NIGHT BUT MIN TEMPS WILL BE AROUND 10 DEGREES WARMER AND 
NO FROST IS EXPECTED.  
     
SATURDAY...HIGH PRESSURE SHIFTS FURTHER SOUTH ACROSS CNTL FL 
WHILE LOW PRESSURE TRACKS ACROSS VA AND NC. THE TIGHT GRADIENT 
BETWEEN THE TWO WILL PRODUCE BREEZY AND WARM SW WINDS. WITH
SUNNY SKIES EXPECTED...HIGH TEMPS WILL BE WELL INTO THE 70S 
AT MOST LOCALES...INCLUDING THE COAST. 

SATURDAY NIGHT...RIDGE OF HIGH PRESSURE SHIFTS NORTH INTO 
THE AREA. WITH CLEAR SKIES AND LIGHT WINDS LOW TEMPS WILL
FALL INTO THE MID/UPPER 40S INLAND AND AROUND 50 COAST 
WHICH IS BELOW NORMAL. 
      
.LONG TERM...(SUNDAY-THURSDAY)...

THE ABOVE NORMAL TEMPERATURE READINGS AND DRY AIRMASS WILL CONTINUE 
INTO EARLY NEXT WEEK WITH HIGH PRESSURE SHIFTING EAST OF THE REGION. 
THE NEXT FRONTAL BOUNDARY SHOULD MOVE SOUTHEAST ACROSS REGION IN THE 
MONDAY NIGHT TO TUESDAY TIMEFRAME. MODELS ARE TRENDING TOWARD A 
WEAKENING TREND WITH THE FRONT...AS THE BETTER ENERGY SHIFTS 
NORTHEAST. SO...CONTINUE TO FORECAST LOW POPS FOR THIS PERIOD. HIGH 
PRESSURE PUSHES SOUTH BEHIND THE BOUNDARY FOR MIDWEEK. NOT MUCH OF A 
SOUTHERN EXTENT TO THE COOLER AIRMASS BEHIND THIS SYSTEM...SO ONLY A 
SLIGHT COOL DOWN EXPECTED.

&&

.AVIATION...VFR CONTINUES. WINDS WILL AROUND 10 KT FROM THE N AND NE.
WINDS WILL BE LESS THAN 10 KT BY EARLY THIS EVENING. 

&&

.MARINE...SMALL CRAFT ADVY CONTINUES FOR THE OFFSHORE WATERS DUE
TO MARGINAL WIND SPEED BUT SEAS OF ABOUT 7 FT AT 41012. WINDS WILL 
BE WEAK TONIGHT INTO FRI AS HIGH PRES MOVES CLOSER TO THE AREA.
OFFSHORE FLOW PREVAILS DURING THE WEEKEND WITH NOCTURNAL SURGES
IN S-SWLY WINDS. S-SW FLOW CONTINUES MON BEFORE NEXT FRONTAL PASSAGE
ON TUE. 

.RIP CURRENTS...ELY SWELLS LIKELY TO CONTINUE ON FRI WITH A 
MODERATE RISK AND CONTINUED N-S LONG-SHORE CURRENTS.

&&

.FIRE WEATHER...HAVE GONE AHEAD AND CANCELLED THE RED FLAG
FOR ST JOHNS AND FLAGLER COUNTIES WHERE RH VALUES HAVE NOT
FALLEN TO 28% AND ANY DURATIONS ARE LIKELY TOO BE SHORT FOR FLAGS.
RED FLAG CONTINUES FOR PUTNAM AND MARION COUNTIES REST OF
THE AFTN. A FIRE WX WATCH MAY BE NEEDED ON FRI FOR SE ZONES
WHERE ERC VALUES MAY BE AROUND 37. DECISION WILL BE MADE LATE 
TODAY WHETHER A FIRE WX WATCH IS NEEDED FOR THESE AREAS.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  34  72  46  79 /  10  10  10  10 
SSI  40  68  49  76 /  10  10   0  10 
JAX  34  71  44  78 /   0   0   0   0 
SGJ  38  68  49  74 /   0   0   0   0 
GNV  33  72  41  77 /   0   0   0   0 
OCF  34  73  40  78 /   0   0   0   0 

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...FROST ADVISORY FROM 4 AM TO 9 AM EDT FRIDAY FOR ALACHUA-BAKER-
     BRADFORD-CLAY-COLUMBIA-DUVAL-GILCHRIST-HAMILTON-MARION-
     NASSAU-PUTNAM-SUWANNEE-UNION.

     RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR MARION-PUTNAM.

GA...FROST ADVISORY FROM 4 AM TO 9 AM EDT FRIDAY FOR APPLING-ATKINSON-
     BACON-BRANTLEY-CHARLTON-CLINCH-COFFEE-ECHOLS-INLAND CAMDEN-
     INLAND GLYNN-JEFF DAVIS-PIERCE-WARE-WAYNE.

AM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING 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.

&&

$$

PP/ARS/KG