562
FXUS62 KJAX 201603
AFDJAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
1103 AM EST FRI DEC 20 2024
..BREEZY THIS AFTERNOON AND THEN TURNING COLDER THIS EVENING
..LIGHT FREEZE FOR INLAND LOCATIONS ON SATURDAY NIGHT
..ANOTHER LIGHT FREEZE FOR INLAND SOUTHEAST GA SUNDAY 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
UPDATE
ISSUED AT 1104 AM EST FRI DEC 20 2024
LATE MORNING SURFACE ANALYSIS DEPICTS A REINFORCING COLD FRONT
THAT WAS DIVING ACROSS THE OHIO AND TENNESSEE VALLEYS, EXTENDING
WESTWARD ACROSS THE SOUTHERN PLAINS STATES. MEANWHILE, ARCTIC HIGH
PRESSURE (1040 MILLIBARS) WAS BUILDING OVER THE NORTHERN PLAINS
STATES AND THE UPPER MIDWEST IN THE WAKE OF THIS FRONT. ALOFT...A
POTENT SHORTWAVE TROUGH PROGRESSING ACROSS THE OHIO VALLEY AND THE
EASTERN GREAT LAKES WAS DIGGING A LONGWAVE TROUGH ACROSS THE
EASTERN HALF OF THE NATION. A PATCH OF LOWER STRATUS CLOUD COVER
WAS MIGRATING SOUTHEASTWARD ACROSS NORTH CENTRAL FL LATE THIS
MORNING, WITH FAIR SKIES PREVAILING ELSEWHERE. TEMPERATURES AT 16Z
GENERALLY RANGED FROM 55-60 DEGREES, WITH BREEZY WEST-NORTHWESTERLY
WINDS OVERSPREADING OUR REGION. DEWPOINTS RANGED FROM AROUND 40
FOR LOCATIONS NEAR THE ALTAMAHA RIVER TO THE LOWER 50S IN NORTH
CENTRAL AND COASTAL NORTHEAST FL.
TROUGHING ALOFT WILL CONTINUE TO DIG OVER THE EASTERN HALF OF THE
NATION THROUGH SATURDAY NIGHT, DRIVING THE AFOREMENTIONED
REINFORCING COLD FRONT ACROSS OUR AREA DURING THE OVERNIGHT HOURS
TONIGHT. THIS WEATHER PATTERN WILL KEEP A TIGHT LOCAL PRESSURE
GRADIENT IN PLACE ACROSS OUR REGION THROUGH SATURDAY AFTERNOON,
WITH BREEZY WEST-NORTHWESTERLY WINDS THIS AFTERNOON SHIFTING TO
NORTHWESTERLY OVERNIGHT. PLENTY OF SUNSHINE AND A DRYING AIR MASS
WILL ALLOW HIGHS TO CLIMB INTO THE 60S AREA-WIDE THIS AFTERNOON.
COLD AIR ADVECTION WILL DROP LOWS TO THE LOW AND MID 30S ACROSS
INLAND SOUTHEAST GA, THE SUWANNEE VALLEY, AND THE I-10 CORRIDOR TO
THE WEST OF METROPOLITAN JACKSONVILLE BY EARLY SATURDAY MORNING.
SUSTAINED WINDS OF 5-10 MPH AT THESE INLAND LOCATIONS WILL LIKELY
ONLY ALLOW FOR PATCHY FROST FORMATION DURING THE PREDAWN AND EARLY
MORNING HOURS ON SATURDAY MORNING. LOWS ELSEWHERE WILL FALL TO THE
UPPER 30S AND LOWER 40S. WIND CHILLS DURING THE PREDAWN AND EARLY
MORNING HOURS WILL FALL TO THE MID AND UPPER 20S ACROSS SOUTHEAST
GA AND THE I-10 CORRIDOR, WITH LOW AND MID 30S FORECAST ELSEWHERE.
SHORT TERM
(SATURDAY THROUGH SUNDAY NIGHT)
ISSUED AT 317 AM EST FRI DEC 20 2024
FAIR, CHILLIER, WEATHER WILL SETTLE IN THIS WEEKEND AS HIGH
PRESSURE BUILDS TO THE NORTH. HIGHS WILL NOT MAKE IT OUT OF THE
50S ON SATURDAY FOR ALL OF SOUTHEAST GEORGIA AND MOST OF NORTHEAST
FLORIDA, WITH ONLY A FEW SPOTS IN FLAGLER AND MARION POTENTIALLY
HITTING 60 DEGREES. FROST DEVELOPMENT IS LIKELY FOR INLAND
SOUTHEAST GEORGIA AND THE SUWANNEE VALLEY ON SATURDAY NIGHT, AS
LOW TEMPERATURES DROP INTO THE LOWER TO MID 30S IN THOSE AREAS.
ELSEWHERE, ALONG THE COAST AND THE REST OF NORTHEAST FLORIDA,
TEMPERATURES WILL STAY IN THE UPPER 30S TO MID 40S, WARMEST ON THE
COAST. TEMPERATURES WILL WARM UP ABOUT 5 DEGREES AREA-WIDE SUNDAY,
WITH HIGHS REACHING THE MID 50S TO MID 60S WITH SUNNY SKIES AND
NORTHEASTERLY WINDS. LOWS WILL FALL TO JUST NEAR FREEZING FOR
PORTIONS OF INLAND SOUTHEAST GEORGIA, WITH ANOTHER ROUND OF FROST
LIKELY IN THE SAME LOCATIONS.
LONG TERM
(MONDAY THROUGH THURSDAY)
ISSUED AT 317 AM EST FRI DEC 20 2024
HIGH PRESSURE WILL CONTINUE TO BUILD AND SHIFT TO THE NORTHEAST
EARLY NEXT WEEK, WITH A COASTAL TROUGH LINGERING NEAR THE ATLANTIC
COAST. DUE TO THIS COASTAL TROUGH, THERE WILL BE AN ISOLATED
CHANCE OF SHOWERS NEAR THE COAST ON MONDAY AND TUESDAY, PRIMARILY
IN THE AFTERNOONS AS ONSHORE WINDS PICK UP. A WAVE WILL PUSH
THROUGH OFF THE GULF MID-WEEK, ALLOWING FOR WIDESPREAD SHOWER
CHANCES IN THE 20-30% RANGE ON WEDNESDAY AND THURSDAY.
TEMPERATURES WILL GRADUALLY WARM UP EACH DAY NEXT WEEK, REACHING
THE 60S TO 70S, WITH LOWS REMAINING ABOVE 40 DEGREES EACH NIGHT.
AVIATION
(12Z TAFS)
ISSUED AT 447 AM EST FRI DEC 20 2024
INCREASING WNW WINDS WERE STARTING TO ADVECT THE LOW STRATUS AND
FOG EASTWARD, WITH VISIBILITY IMPROVING AT SSI, JAX, AND VQQ TO
ABOVE 4SM BUT LOW LIFR TO IFR CEILINGS CONTINUED. OVER THE NEXT
1-2 HRS, EXPECT CEILINGS WILL FURTHER IMPROVE AT THESE LOCATIONS
TO MVFR THEN VFR THROUGH 11-13Z. LOWER CEILINGS WILL LINGER NEAR
THE COAST THROUGH ABOUT 12-14Z IMPACTING SSI, CRG AND SGJ.
AFTER LOW STRATUS LIFTS BY MID-MORNING, CEILINGS LIFT AS BREEZY
WNW WINDS DEVELOP WITH SPEEDS 10-13 KTS AND GUSTS AROUND 20 KTS
INTO THE AFTERNOON WITH VFR CONDITIONS. ELEVATED NW WINDS
CONTINUED OVERNIGHT 5-10 KTS TONIGHT AS A DRY FRONT MOVES ACROSS
THE AREA WITH VFR CONDITIONS.
MARINE
ISSUED AT 1104 AM EST FRI DEC 20 2024
ARCTIC HIGH PRESSURE BUILDING OVER THE UPPER MIDWEST AND THE GREAT
LAKES STATES WILL PUSH A REINFORCING, DRY COLD FRONT ACROSS OUR
LOCAL WATERS THIS EVENING. BREEZY WEST-NORTHWESTERLY WINDS THIS
MORNING WILL STRENGTHEN THIS AFTERNOON, WITH SPEEDS REACHING SMALL
CRAFT ADVISORY LEVELS OF AROUND 20 KNOTS OFFSHORE. WINDS WILL
SHIFT TO NORTHWESTERLY THIS EVENING AND WILL CONTINUE TO GRADUALLY
INCREASE, RESULTING IN SEAS BUILDING TO THE 5-7 FOOT RANGE OFFSHORE
AND SMALL CRAFT ADVISORY LEVEL WIND SPEEDS OF AROUND 20 KNOTS NEAR
SHORE. SMALL CRAFT ADVISORY CONDITIONS WILL PERSIST ACROSS OUR
LOCAL WATERS THROUGH SATURDAY MORNING, WITH SPEEDS AND SEAS THEN
FALLING BACK TO CAUTION LEVELS ON SATURDAY AFTERNOON.
HIGH PRESSURE WILL CONTINUE TO SHIFT EASTWARD ACROSS THE GREAT
LAKES REGION THIS WEEKEND, REACHING THE MID-ATLANTIC COAST BY
MONDAY AFTERNOON. THIS WEATHER PATTERN WILL RESULT IN WINDS
SHIFTING TO NORTHEASTERLY BY SATURDAY NIGHT AND SUNDAY, WITH
CAUTION CONDITIONS OF 15-20 KNOTS AND SEAS OF 4-6 FEET FORECAST
BOTH NEAR SHORE AND OFFSHORE FROM SATURDAY AFTERNOON THROUGH EARLY
NEXT WEEK, WITH WINDS AND SEAS APPROACHING SMALL CRAFT ADVISORY
LEVELS LATE THIS WEEKEND AND EARLY NEXT WEEK OFFSHORE. COASTAL
TROUGHING WILL DEVELOP OVER OUR NEAR SHORE WATERS BY SUNDAY NIGHT
AND MONDAY, WITH THIS FEATURE GENERATING SCATTERED SHOWERS THAT
WILL PERSIST THROUGH AT LEAST MIDWEEK.
RIP CURRENTS: A LONG PERIOD EASTERLY OCEAN SWELL WILL KEEP A
MODERATE RIP CURRENT RISK IN PLACE TODAY AT AREA BEACHES. BUILDING
SURF CONDITIONS THIS WEEKEND WILL RESULT IN A MODERATE RISK ON
SATURDAY, WITH A HIGH RISK LIKELY FOR THE NORTHEAST FL BEACHES ON
SUNDAY AS BREEZY ONSHORE WINDS DEVELOP.
FIRE WEATHER
ISSUED AT 1104 AM EST FRI DEC 20 2024
BREEZY WEST-NORTHWESTERLY SURFACE AND TRANSPORT WINDS WILL USHER A
DRIER AIR MASS INTO OUR REGION THIS AFTERNOON, WITH MINIMUM
RELATIVE HUMIDITY VALUES FALLING TO THE 30-35 PERCENT RANGE.
THESE BREEZY CONDITIONS WILL RESULT IN GOOD DAYTIME DISPERSION
VALUES AREA-WIDE TODAY. SURFACE AND TRANSPORT WINDS WILL SHIFT TO
NORTHERLY EARLY ON SATURDAY MORNING, WITH LOW MIXING HEIGHTS
RESULTING IN GENERALLY FAIR DAYTIME DISPERSION VALUES ACROSS OUR
REGION. A DRY AIR MASS WILL PERSIST AT INLAND LOCATIONS ON
SATURDAY, FOLLOWED BY SURFACE AND TRANSPORT WINDS SHIFTING TO
NORTHEASTERLY BY EARLY SUNDAY MORNING. BREEZY SURFACE AND
TRANSPORT SPEEDS WILL YIELD GOOD DAYTIME DISPERSION VALUES ON
SUNDAY ACROSS NORTH CENTRAL AND COASTAL NORTHEAST FL, WHILE
CONTINUED LOW MIXING HEIGHTS KEEPS VALUES FAIR ELSEWHERE. THE DRY
AIR MASS WILL RETREAT TO INLAND SOUTHEAST GA ON SUNDAY AFTERNOON.
PRELIMINARY POINT TEMPS/POPS
AMG 62 33 54 29 / 0 0 0 0
SSI 64 38 54 41 / 0 0 0 0
JAX 66 37 56 36 / 0 0 0 0
SGJ 68 42 56 43 / 0 0 0 0
GNV 66 38 57 36 / 0 0 0 0
OCF 68 38 58 36 / 0 0 0 0
JAX WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GA...NONE.
AM...SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 10 AM EST
SATURDAY FOR AMZ450-452-454.
SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 10 AM EST
SATURDAY FOR AMZ470-472-474.
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