Area Forecast Discussion
Issued by NWS Jacksonville, FL

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FXUS62 KJAX 010924
AFDJAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
424 AM EST SUN FEB 1 2015

...MILD TEMPERATURES EXPECTED TODAY...

...RAIN CHANCES SLOWLY INCREASE TONIGHT AS NEXT FRONT APPROACHES...

.NEAR TERM /THROUGH TONIGHT/...

EARLY THIS MORNING...SEASONABLY COOL THIS MORNING WITH UPPER 30S/40S
OVER INLAND AREAS AND NEAR 50 ALONG THE COAST. JUST A FEW PASSING
HIGH CLOUDS AT TIMES AND SOME PATCHY 3-5 MILE VSBYS IN LIGHT FOG BUT
NOT SIGNIFICANT TO MENTION IN GRIDS AND/OR PUBLIC FORECAST.

TODAY...SURFACE HIGH PRESSURE JUST NORTHEAST OF THE REGION WILL
CONTINUE TO TRACK EAST INTO THE WRN ATLC AHEAD OF NEXT FRONTAL
SYSTEM. STEERING FLOW WILL BECOME SOUTHERLY AND EXPECT THIS TO PUSH
MAX TEMPS ABOUT 10 DEGREES WARMER THAN YESTERDAY INTO THE 70-75
DEGREE RANGE EXCEPT LOCAL SELY FLOW ALONG THE COAST WILL KEEP MAX
TEMPS IN THE 60S AT THE BEACHES. SKIES WILL BE MOSTLY TO PARTLY
SUNNY AS PERIODS OF HIGH CLOUDS CONTINUE TO PUSH ACROSS THE REGION
FROM THE WEST ALONG WITH SOME SCATTERED AFTERNOON CUMULUS
DEVELOPMENT. SOUTH WINDS WILL INCREASE TO 15 MPH WITH GUSTS OF 20-25
MPH POSSIBLE AT TIMES. ISOLD SHOWER ACTIVITY MAY DEVELOP OVER THE
OFFSHORE COASTAL WATERS IN THE S/SE FLOW BUT ARE EXPECTED TO REMAIN
AWAY FROM THE COAST.

TONIGHT...TIMING FOR THE START OF FRONTAL PCPN HAS SLOWED SLIGHTLY
IN MOST OF THE MODEL OUTPUT...BUT OVERALL FORECAST REMAINS SIMILAR
WITH RAIN CHANCES INCREASING SLOWLY...MAINLY AFTER MIDNIGHT FROM
NORTHWEST TO SOUTHEAST...WITH POPS RANGING FROM 20-50% ACRS NE FL BY
MORNING AND 50-80% ACRS SE GA BY MORNING. RAINFALL AMOUNTS WILL
GENERALLY REMAIN LIGHT...LESS THAN A QUARTER OF AN INCH THROUGH
TONIGHT. SOUTHERLY WINDS WILL REMAIN ELEVATED TONIGHT AT 10-15 MPH
AND GUSTY AHEAD OF THE FRONT AND THIS WILL KEEP MIN TEMPS ELEVATED
IN THE 55-60 DEG RANGE.

.SHORT TERM /MONDAY AND TUESDAY/...

MONDAY WILL START OUT ON THE WET AND MILD SIDE AND THEN TRANSITION
TO DRY AND COOLER CONDITIONS DURING THE DAY AS A COLD FRONT
QUICKLY SWEEPS THROUGH THE REGION. GENERALLY SPEAKING...THE LIFT
WITH THIS SYSTEM IS MODEST AT BEST BUT ENOUGH MOISTURE WILL MOVE
NORTHEAST OUT OF THE GULF TO SUPPORT NUMEROUS COVERAGE OF MOSTLY
LIGHT TO MODERATE RAIN SHOWERS ALONG THE COLD FRONT MONDAY
MORNING. RAINFALL AMOUNTS WILL AVERAGE LESS THAN A THIRD OF AN
INCH. A TIGHTENING PRESSURE GRADIENT ALONG THE FRONT WILL SUPPORT
BREEZY TO LOCALLY WINDY CONDITIONS DURING THE DAY ON MONDAY. THE
FRONT AND ASSOCIATED RAIN WILL PUSH SOUTH OF OUR LOCAL FORECAST
AREA BY MID TO LATE AFTERNOON.

MONDAY NIGHT WILL BE SIGNIFICANTLY COLDER THAN SUNDAY NIGHT...AS
MUCH AS 20 TO 25 DEGREES COLDER. TEMPS WILL DROP INTO THE LOW TO
MID 30S FOR ALL AREAS EXCEPT ALONG THE NE FL COAST AND ST JOHNS
RIVER BASIN. A LIGHT FREEZE IS EXPECTED ACROSS INLAND SE GA AS
WELL AS PORTIONS OF INLAND NE FL...MAINLY ALONG THE I-10 CORRIDOR
AND ACROSS THE SUWANNEE RIVER VALLEY.

ON TUESDAY...A CANOPY OF VERY HIGH CIRRUS CLOUDS IS NOT EXPECTED
TO BE THICK ENOUGH TO HAVE A SIGNIFICANT IMPACT ON MAX
TEMPS...THUS WE LEANED HEAVILY ON THE WARMER NAM GUIDANCE FOR
TEMPERATURES ON TUESDAY. THIS HOWEVER STILL TRANSLATES TO COOLER
THAN NORMAL TEMPS WITH HIGHS RANGING FROM THE MID 50S NORTH TO THE
MID 60S SOUTH.

WE HAVE LOWERED TEMPS FOR TUESDAY NIGHT GIVEN THAT COOL HIGH
PRESSURE RIDGING WILL CONTINUE TO LINGER OVER THE AREA. INCREASING
MID LEVEL CLOUDS THOUGH WILL PRECLUDE ANY FREEZING TEMPS. LOWS
WILL RANGE FROM THE MID TO UPPER 30S INLAND TO THE MID TO UPPER
40S ALONG THE COAST AND ACROSS OUR SOUTHERN ZONES WHERE THICKER
CIRRUS SHIELD IS ANTICIPATED.

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...

HIGH PRESSURE OVER THE MID ATLANTIC COAST WILL MOVE OFFSHORE ON
WEDNESDAY. LOW LEVEL ONSHORE FLOW WILL PREVAIL AS A COASTAL TROUGH
DEVELOPS JUST OFFSHORE WITH A FEW SHOWERS POSSIBLE OVER THE
COASTAL WATERS. THE LOCAL STEERING FLOW IS ACTUALLY PROGGED TO
BECOME SOUTHWESTERLY AND ALTHOUGH THIS WILL ALLOW TEMPS TO MODIFY
A BIT...COOLER THAN NORMAL TEMPS ARE STILL ANTICIPATED FOR MUCH OF
THE REGION ON WEDNESDAY.

A SOUTHERN STREAM SHORTWAVE TROUGH WILL INDUCE WEAK SURFACE
CYCLOGENESIS ACROSS THE WESTERN GULF OF MEXICO WEDNESDAY NIGHT.
THIS LOW WILL TRANSLATE EASTWARD WITH AN ASSOCIATED WARM FRONT
EXPECTED TO LIFT NORTH AND POSITION ACROSS OUR REGION WEDNESDAY
NIGHT AND THURSDAY. IT SHOULD BE NOTED THAT THE LATEST MODEL
SUITE IS FARTHER SOUTH WITH THE TRACK OF THE LOW (ACROSS SOUTH
CENTRAL FLORIDA)...BUT THE MODELS HAVE SHOWN A TRACK RECORD THIS
WINTER OF BEING TOO FAR SOUTH IN THE DAY 4 TO 5 TIMEFRAME WITH
THESE GULF LOWS. GIVEN THIS...THE LOW IS MORE LIKELY TO TRACK
ACROSS OUR AREA. STRONG LIFT AND ABUNDANT MOISTURE WITH THIS
SYSTEM WILL BRING A SIGNIFICANT INCREASE IN RAIN CHANCES TO OUR
LOCAL FORECAST AREA ON THURSDAY.

THE MODELS CONTINUE TO DISAGREE ON HOW FAST TO MOVE THE LOW OUT
OF OUR REGION. THE ECMWF IS MUCH MORE PROGRESSIVE WITH MOVING THE
LOW WELL AWAY FROM OUR AREA THURSDAY NIGHT. THE GFS HOWEVER
CONTINUES TO SHOW A STRONG NORTHERN STREAM SHORTWAVE TROUGH
DIGGING INTO OUR AREA ON FRIDAY...WHICH IN TURN HOLDS THE LOW UP A
LITTLE LONGER OFF OUR SHORE ON FRIDAY. THIS WOULD KEEP RAIN
CHANCES HIGHER AND RESULT IN WINDY CONDITIONS ALONG OUR COAST ON
FRIDAY BUT CONFIDENCE REMAINS QUITE LOW WITH THIS PART OF THE
FORECAST. HIGHER CONFIDENCE EXISTS IN A DRY FORECAST BY SATURDAY
WITH COOLER THAN NORMAL TEMPERATURES AS COOL HIGH PRESSURE BUILDS
IN FROM THE NORTH.

&&

.AVIATION... VFR WITH INCREASING HIGH CLOUDS AND SCATTERED CU FIELD
THIS AFTERNOON AROUND 4000 FEET. WILL HAVE TO ADD VCSH TO NEXT TAF
ISSUANCE IN THE 06-12Z TIME FRAME TONIGHT AS FRONTAL SHOWER ACTIVITY
PUSHES CLOSER TO THE TAF SITES.

&&

.MARINE... NO CHANGES TO ONGOING FORECAST AS LIGHT EASTERLY FLOW
BECOMES SOUTH AND INCREASES THIS AFTERNOON WITH SPEEDS REACHING 20-
25 KNOTS TONIGHT ACROSS THE OFFSHORE WATERS AND SMALL CRAFT ADVISORY
IS ALREADY IN PLACE. THE NEARSHORE WATERS WILL COME CLOSE TO
ADVISORY CONDS IN THE 15-20 KNOT RANGE...BUT NOT HIGH ENOUGH
CONFIDENCE TO ISSUE SCA WITH THIS PACKAGE. SEAS BUILDING AS HIGH AS
6-9 FT OVER THE OFFSHORE WATERS BY LATER TONIGHT.

INCREASED SOUTHWEST WINDS WILL VEER TO THE WEST NORTHWEST MONDAY
AFTERNOON AS A COLD FRONT MOVES THROUGH THE REGION. ADVISORY
CONDITIONS WILL CONTINUE OFFSHORE THROUGH MONDAY NIGHT. WILL
CONTINUE TO SHOW CAUTION CONDITIONS FOR THE NEARSHORE WATERS BUT
WINDS WILL BE NEAR ADVISORY LEVELS AT TIMES ON MONDAY. CONDITIONS
WILL BE MUCH IMPROVED TUESDAY INTO TUESDAY NIGHT. A MORE
SIGNIFICANT EVENT IS EXPECTED LATE IN THE WEEK WITH STRONG WINDS
AND HIGH SEAS EXPECTED BY FRIDAY AS A GULF LOW TRACKS ACROSS THE
REGION.

RIP CURRENTS: MODERATE RISK CONTINUES TODAY AS EAST SWELLS IN THE 2-
3 FT RANGE WITH PERIODS CLOSE TO 10 SECONDS IMPACT THE COAST.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  71  55  58  30 /  10  60  70   0
SSI  64  57  65  35 /  10  50  50   0
JAX  72  58  65  34 /  10  40  50   0
SGJ  70  60  70  40 /  10  30  50   0
GNV  74  59  66  33 /   0  40  50   0
OCF  75  59  68  35 /   0  30  50   0

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 5 AM EST TUESDAY
     FOR WATERS FROM ALTAMAHA SOUND GA TO FERNANDINA BEACH FL
     FROM 20 TO 60 NM-WATERS FROM FERNANDINA BEACH TO ST.
     AUGUSTINE FL FROM 20 TO 60 NM-WATERS FROM ST. AUGUSTINE TO
     FLAGLER BEACH FL FROM 20 TO 60 NM.

&&

$$

HESS/SHULER


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