432
FXUS62 KJAX 192010
AFDJAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
310 PM EST THU DEC 19 2024
..DENSE FOG REDEVELOPS ALONG THE I-95 CORRIDOR TONIGHT
..BECOMING BREEZY ON FRIDAY AND TURNING COLDER FRIDAY NIGHT
..LIGHT FREEZE EXPECTED WELL INLAND ON SATURDAY NIGHT
FOR THE LATEST NE FL AND SE GA DAILY KEY MESSAGES PLEASE VISIT:
HTTPS://WWW.WEATHER.GOV/MEDIA/JAX/BRIEFINGS/NWS-JAX-BRIEFING.PDF
SYNOPSIS
ISSUED AT 310 PM EST THU DEC 19 2024
AFTERNOON SURFACE ANALYSIS DEPICTS A COLD FRONT PUSHING SOUTHWARD
TOWARDS THE INTERSTATE 4 CORRIDOR IN NORTH CENTRAL FL, WITH
WEAKENING HIGH PRESSURE (1027 MILLIBARS) BRIEFLY BUILDING OVER
THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEYS IN THE WAKE OF
THIS FRONT. MEANWHILE, A REINFORCING COLD FRONT WAS PUSHING
SOUTHEASTWARD ACROSS THE NORTHERN PLAINS AND THE UPPER MIDWEST,
WITH ARCTIC HIGH PRESSURE (1039 MILLIBARS) BUILDING OVER THE
CANADIAN PRAIRIES IN THE WAKE OF THIS BOUNDARY. ALOFT...A
SHARP TROUGH WAS PROGRESSING EASTWARD ALONG THE SOUTHEASTERN
SEABOARD, WHILE A POTENT SHORTWAVE TROUGH WAS PUSHING TOWARDS LAKE
MICHIGAN. LATEST GOES-EAST VISIBLE SATELLITE IMAGERY DEPICTS A
BANK OF SEA FOG OVER THE NORTHEAST FL WATERS BRUSHING THE
IMMEDIATE COAST FROM AROUND ST. AUGUSTINE AND POINTS SOUTHWARD,
WHILE A CUMULUS FIELD WAS PUSHING SLOWLY SOUTHEASTWARD FROM
COASTAL SOUTHEAST GA AND ACROSS MOST OF NORTHEAST AND NORTH
CENTRAL FL. FAIR SKIES PREVAIL ELSEWHERE, WITH TEMPERATURES AT 20Z
MOSTLY IN THE 70S AT INLAND LOCATIONS, WHILE 60S PREVAIL ALONG
COASTAL ST. JOHNS COUNTY WHERE SEA FOG HAS MOVED ONSHORE. RANGING
FROM THE UPPER 60S TO LOWER 70S FOR LOCATIONS NORTH OF THE
FRONTAL BOUNDARY, WHILE UPPER 70S WERE CONFINED TO LOCATIONS SOUTH
OF THE FRONT ACROSS NORTH CENTRAL FL. DEWPOINTS AT 20Z RANGED
FROM THE MID 50S ACROSS INLAND SOUTHEAST GA TO THE MID 60S IN
NORTH CENTRAL AND COASTAL NORTHEAST FL.
NEAR TERM
(THROUGH TONIGHT)
ISSUED AT 310 PM EST THU DEC 19 2024
DENSE SEA FOG WILL ALONG COASTAL ST. JOHNS AND FLAGLER COUNTIES
WILL GRADUALLY EDGE SOUTHWARD THROUGH SUNSET, WITH COMMUNITIES
ALONG THE OCEANFRONT AND EAST OF STATE ROAD A-1A FROM AROUND ST.
AUGUSTINE SOUTHWARD GENERALLY BEING IMPACTED. THERE MAY BE A
BRIEF WINDOW OF CLEARING ALONG THESE COASTAL COMMUNITIES EARLY
THIS EVENING BEFORE SEA FOG REDEVELOPS AND MAKES A STRONGER INLAND
PUSH DURING THE MID TO LATE EVENING HOURS.
THE REINFORCING ARCTIC COLD FRONT WILL DIG SOUTHEASTWARD TOWARDS
THE OHIO AND TENNESSEE VALLEYS OVERNIGHT, WITH A LOOSENING LOCAL
PRESSURE GRADIENT EXPECTED THIS EVENING. LEFTOVER LOW LEVEL
MOISTURE LINGERING IN THE WAKE OF TODAY'S FRONTAL PASSAGE WILL
SET THE STAGE FOR ANOTHER ROUND OF LOW STRATUS AND DENSE FOG
OVERNIGHT, WITH COASTAL AREAS EXPECTED TO BE IMPACTED BEFORE
MIDNIGHT, WITH FOG THEN SPREADING INLAND ALONG THE I-95 CORRIDOR
TOWARDS MIDNIGHT AND PERHAPS REACHING THE U.S. HIGHWAY 301
CORRIDOR IN NORTHEAST AND NORTH CENTRAL FL DURING THE PREDAWN
HOURS. LATEST SHORT-TERM, HIGH RESOLUTION GUIDANCE INDICATES THAT
THIS BANK OF FOG AND LOW STRATUS SHOULD BEGIN SHIFTING SOUTH AND
EASTWARD TOWARDS SUNRISE AS OUR LOCAL PRESSURE GRADIENT BEGINS TO
TIGHTEN FROM WEST TO EAST AHEAD OF THE APPROACHING REINFORCING
FRONT. FAIR SKIES SHOULD PREVAIL FOR LOCATIONS WEST OF U.S.-301
OVERNIGHT, ALLOWING FOR LOWS TO FALL INTO THE 40S FOR INLAND
SOUTHEAST GA AND THE SUWANNEE VALLEY, WHILE LOWS ELSEWHERE REMAIN
IN THE 50S.
SHORT TERM
(FRIDAY THROUGH SATURDAY NIGHT)
ISSUED AT 310 PM EST THU DEC 19 2024
A SECONDARY COLD FRONT WILL MOVE INTO AREA FROM THE NORTH FRIDAY
AFTERNOON, AND PUSH TO THE SOUTH FRIDAY NIGHT. THIS FRONT IS
EXPECTED TO PASS THROUGH DRY, BUT WILL USHER IN A PERIOD OF COOLER
WEATHER. HIGH PRESSURE WILL BUILD FROM THE NORTHWEST FRIDAY NIGHT
THROUGH SATURDAY. THE HIGH WILL BUILD MORE TOWARD THE NORTH
SATURDAY NIGHT. A WEAK COASTAL TROUGH IS EXPECTED TO DEVELOP IN
THE ONSHORE FLOW SATURDAY, WHICH COULD PRODUCE A FEW EXTRA COASTAL
CLOUDS. OTHERWISE, THIS IS EXPECTED TO BE A DRY PERIOD, WITH
MAINLY CLEAR SKIES.
THE WARMEST DAY THIS PERIOD WILL BE FRIDAY, WITH HIGHS NEAR TO A
LITTLE ABOVE SEASONAL LEVELS. BELOW NORMAL READINGS ARE EXPECTED
FOR THE REST OF THIS PERIOD. SATURDAY NIGHT WILL BE A LITTLE
COOLER THAN FRIDAY NIGHT, WITH AN INLAND LIGHT FREEZE EXPECTED.
FROST POTENTIAL WILL EXIST BOTH FRIDAY NIGHT AND SATURDAY NIGHT
FOR INLAND AREAS. THIS POTENTIAL WILL AGAIN BE GREATER SATURDAY
NIGHT.
LONG TERM
(SUNDAY THROUGH NEXT THURSDAY)
ISSUED AT 310 PM EST THU DEC 19 2024
THE HIGH CENTER WILL BUILD FROM THE NORTH TO THE NORTHEAST SUNDAY
NIGHT THROUGH TUESDAY. AS THE HIGH BUILDS MORE TOWARD THE
NORTHEAST, THERE IS A CHANCE THAT ANY COASTAL TROUGH WHICH
DEVELOPED OVER THE WEEKEND COULD MOVE ASHORE. MODELS ARE DEPICTING
A CHANCE FOR SHOWERS WITH THIS TROUGH FOR COASTAL COUNTIES.
HIGH PRESSURE WILL REMAIN TO THE NORTHEAST WEDNESDAY INTO THURSDAY,
AS A WAVE MOVES NORTHEAST ACROSS AREA FROM THE GULF. THIS WAVE WILL
BRING POTENTIAL FOR SHOWERS ON WEDNESDAY, WHICH COULD LINGER INTO
THURSDAY.
TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH MONDAY, NEAR NORMAL
TUESDAY, THEN TREND TOWARD ABOVE NORMAL LEVELS FOR WEDNESDAY AND
THURSDAY.
AVIATION
(18Z TAFS)
ISSUED AT 214 PM EST THU DEC 19 2024
VFR CONDITIONS WILL PREVAIL AT THE REGIONAL TERMINALS THROUGH AT
LEAST 00Z. DENSE SEA FOG DEVELOPING OVER THE NEAR SHORE ATLANTIC
WATERS LATE THIS AFTERNOON WILL MOVE ONSHORE JUST AFTER SUNSET
THIS EVENING, WITH LIFR CONDITIONS EXPECTED TO QUICKLY SETTLE IN
SHORTLY AFTER 00Z AT SGJ AND BY 03Z AT SSI. DENSE FOG WILL THEN
SPREAD INLAND TO CRG AND JAX TOWARDS 04Z AND VQQ BEFORE 06Z. A
SMALL WINDOW OF LIFR CONDITIONS IS EXPECTED AT GNV AS THE WESTERN
EDGE OF THIS BANK OF DENSE FOG BRUSHES THE TERMINAL, CURRENTLY
FORECAST FROM AROUND 07Z THROUGH 10Z. THE FOG BANK AND ITS
ACCOMPANYING LIFR CONDITIONS WILL RETREAT EASTWARD DURING THE
PREDAWN AND EARLY MORNING HOURS AS WEST-NORTHWESTERLY SURFACE
WINDS BEGIN TO GRADUALLY STRENGTHEN. CONDITIONS SHOULD QUICKLY
IMPROVE TO MVFR BY 11Z AT GNV, WITH VFR CONDITIONS EXPECTED BEFORE
13Z. IMPROVEMENTS ELSEWHERE SHOULD OCCUR AROUND OR JUST BEFORE
SUNRISE, WITH VFR CONDITIONS EXPECTED TO PREVAIL AT THE REGIONAL
TERMINALS BY 15Z. WEST-NORTHWESTERLY SURFACE WINDS SUSTAINED AT
5-10 KNOTS THIS AFTERNOON AT THE INLAND TERMINALS, WHILE EAST
NORTHEASTERLY WINDS PREVAIL AT THE COASTAL TERMINALS. WINDS WILL
SHIFT TO NORTH OR NORTHEASTERLY AT THE REGIONAL TERMINALS AFTER
SUNSET, WITH SPEEDS DIMINISHING BELOW 5 KNOTS BEFORE MIDNIGHT.
SURFACE WINDS WILL THEN SHIFT TO WEST-NORTHWESTERLY DURING THE
PREDAWN HOURS, WITH SUSTAINED SPEEDS GRADUALLY INCREASING TO
10-15 KNOTS TOWARDS NOON ON FRIDAY.
MARINE
ISSUED AT 310 PM EST THU DEC 19 2024
DENSE SEA FOG WILL GRADUALLY SHIFT SOUTHWARD FOR THE WATERS FROM
AROUND ST. AUGUSTINE THROUGH SUNSET. DENSE SEA FOG IS THEN
EXPECTED TO REDEVELOP THIS EVENING, MAINLY ALONG THE NEAR SHORE
WATERS. THIS FOG SHOULD DISSIPATE BY THE MID-MORNING HOURS ON
FRIDAY AHEAD OF AN APPROACHING STRONG COLD FRONT. NORTHWESTERLY
WINDS WILL INCREASE FURTHER ON FRIDAY AFTERNOON IN THE WAKE OF
THIS DRY COLD FRONTAL PASSAGE, WITH SMALL CRAFT ADVISORY
CONDITIONS INITIALLY DEVELOPING OFFSHORE AND THEN EXPANDING TO THE
NEAR SHORE WATERS DURING THE OVERNIGHT HOURS. STRONG HIGH PRESSURE
BUILDING OVER THE GREAT LAKES THIS WEEKEND IN THE WAKE OF THIS
FRONT WILL SHIFT EASTWARD TOWARDS THE MID-ATLANTIC REGION BY
EARLY NEXT WEEK, RESULTING IN WINDS SHIFTING TO NORTHERLY ON
SATURDAY, NORTHEASTERLY BY SUNDAY, AND THEN EAST-NORTHEASTERLY ON
MONDAY. SMALL CRAFT ADVISORY CONDITIONS WILL LIKELY REDEVELOP
OFFSHORE FROM SUNDAY EVENING THROUGH TUESDAY MORNING. A COASTAL
TROUGH WILL ALSO MATERIALIZE OVER OUR NEAR SHORE WATERS EARLY
NEXT WEEK, RESULTING IN SCATTERED SHOWERS.
RIP CURRENTS: A PERSISTENT EASTERLY OCEAN SWELL WILL COMBINE WITH
ELEVATED BREAKERS OF 3-5 FEET TO KEEP A HIGHER END MODERATE RISK
IN PLACE AT AREA BEACHES TODAY. A LOWER END MODERATE RISK WILL
CONTINUE ON FRIDAY AS THE EASTERLY SWELL LINGERS AND BREAKERS
SUBSIDE TO THE 2-4 FOOT RANGE.
FIRE WEATHER
ISSUED AT 1233 PM EST THU DEC 19 2024
NORTHWESTERLY SURFACE AND TRANSPORT WINDS SHOULD STRENGTHEN
SLIGHTLY THIS AFTERNOON, CREATING FAIR DAYTIME DISPERSION VALUES
AT INLAND LOCATIONS, WHILE LOW VALUES PERSIST ALONG THE IMMEDIATE
COAST. SURFACE AND TRANSPORT WINDS WILL SHIFT TO WEST-
NORTHWESTERLY AND WILL STRENGTHEN BY THE MID-MORNING HOURS ON
FRIDAY, SCOURING OUT LOW CLOUD COVER AND FOG THAT WILL DEVELOP
ALONG THE I-95 CORRIDOR OVERNIGHT AND PUSHING A MUCH DRIER AIR
MASS INTO OUR REGION BY THE AFTERNOON HOURS, WITH MINIMUM
RELATIVE HUMIDITY VALUES FALLING TO THE 30-35 PERCENT RANGE AT
MOST LOCATIONS. BREEZY TRANSPORT WINDS ON FRIDAY WILL CREATE GOOD
DAYTIME DISPERSION VALUES NEARLY AREA-WIDE. SURFACE AND TRANSPORT
WINDS WILL THEN SHIFT TO NORTHERLY BY EARLY SATURDAY, WITH LOW
MIXING HEIGHTS AND LIGHTER SPEEDS RESULTING IN MOSTLY FAIR DAYTIME
DISPERSION VALUES.
PRELIMINARY POINT TEMPS/POPS
AMG 45 63 34 53 / 0 0 0 0
SSI 53 63 39 53 / 10 0 0 0
JAX 52 68 37 54 / 0 0 0 0
SGJ 57 68 43 55 / 0 0 0 0
GNV 53 68 38 56 / 0 0 0 0
OCF 56 70 38 57 / 0 0 0 0
JAX WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GA...NONE.
AM...SMALL CRAFT ADVISORY FROM 9 PM FRIDAY TO 5 AM EST SATURDAY FOR
AMZ450-452-454.
DENSE FOG ADVISORY UNTIL 6 PM EST THIS EVENING FOR AMZ452-454-
472-474.
SMALL CRAFT ADVISORY FROM 1 PM FRIDAY TO 10 AM EST SATURDAY FOR
AMZ470-472-474.
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