777
FXUS62 KJAX 040559
AFDJAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
159 AM EDT THU SEP 4 2025
..NEAR RECORD LOW TEMPERATURES EARLY THIS MORNING
..MINOR FLOODING CONTINUES WITHIN THE ST. JOHNS RIVER BASIN
..HOT AND HUMID WEATHER RETURNS FRIDAY THROUGH THE WEEKEND
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 159 AM EDT THU SEP 4 2025
OVERNIGHT SURFACE ANALYSIS DEPICTS A WEAK PRESSURE PATTERN OVER
OUR REGION, WHILE A FRONTAL BOUNDARY REMAINS STATIONARY OVER THE
FLORIDA STRAITS AND THE NORTHWESTERN BAHAMAS. MEANWHILE, A COLD
FRONT WAS PUSHING EAST-SOUTHEASTWARD ACROSS THE EASTERN GREAT
LAKES, THE OHIO VALLEY AND THE MID-MISSISSIPPI VALLEY.
ALOFT...ZONAL FLOW PREVAILS LOCALLY, AS OUR REGION LIES AT THE
BASE OF DEEP TROUGHING IN PLACE OVER THE GREAT LAKES AND UPPER
MIDWEST. A POTENT SHORTWAVE TROUGH WAS MIGRATING EASTWARD WITHIN
THIS ZONAL FLOW PATTERN ACROSS NORTHERN PORTIONS OF GA. LATEST
GOES-EAST DERIVED TOTAL PRECIPITABLE WATER IMAGERY INDICATES
THAT AN UNSEASONABLY DRY AIR MASS HAS OVERSPREAD OUR AREA, WITH
PWATS OF LESS THAN 1.25 INCHES FOR LOCATIONS ALONG AND NORTH OF
INTERSTATE 10, WHILE VALUES AROUND 1.5 INCHES WERE CONFINED TO
NORTH CENTRAL FL. DEEPER MOISTURE PREVAILS ALONG AND SOUTH OF THE
INTERSTATE 4 CORRIDOR, CLOSER TO THE PERSISTENT, STALLED FRONTAL
BOUNDARY. MARINE STRATOCUMULUS CONTINUES TO STREAM ONSHORE ACROSS
FLAGLER COUNTY, WITH ISOLATED COASTAL SHOWERS EARLIER TONIGHT
FOR LOCATIONS SOUTH OF BUNNELL RECENTLY DISSIPATING. FAIR SKIES
OTHERWISE PREVAIL ACROSS OUR AREA, WITH TEMPERATURES AND DEWPOINTS
IN THE 60S AT MOST INLAND LOCATIONS AS OF 06Z, WHILE LOW AND MID
70S PREVAIL AT COASTAL LOCATIONS AND FOR PORTIONS OF NORTH CENTRAL
FL.
NEAR TERM
(TODAY AND TONIGHT)
ISSUED AT 159 AM EDT THU SEP 4 2025
FAIR SKIES AND DECOUPLING WINDS AT INLAND LOCATIONS WILL ALLOW
TEMPERATURES TO FALL TO NEARLY DAILY RECORD LOWS AT OUR DUVAL
COUNTY CLIMATE SITES EARLY THIS MORNING. SEE "CLIMATE" SECTION
BELOW FOR DETAILS.
ZONAL FLOW ALOFT WILL PREVAIL ACROSS OUR REGION TODAY AS TROUGHING
REMAINS SITUATED OVER THE UPPER MIDWEST AND THE GREAT LAKES, WITH
THIS FEATURE BEING REINFORCED BY ANOTHER POTENT SHORTWAVE TROUGH
DIVING SOUTHEASTWARD FROM THE DAKOTAS THIS AFTERNOON. A DRY AIR
MASS WILL REMAIN ENTRENCHED ACROSS SOUTHEAST GA AND NORTHEAST FL
AS A FRONTAL BOUNDARY BEGINS TO CREEP NORTHWARD FROM THE FL
STRAITS TOWARDS SOUTH FL, WITH PWATS REMAINING BELOW 1.5 INCHES
TODAY AND TONIGHT. JUST ENOUGH MOISTURE MAY BE IN PLACE FOR
ISOLATED, LOW-TOPPED CONVECTION TO DEVELOP LATE THIS AFTERNOON AND
EARLY THIS EVENING ACROSS NORTH CENTRAL FL, MAINLY FROM COLLIDING
MESOSCALE BOUNDARIES SUCH AS THE INLAND MOVING ATLANTIC AND GULF
COAST SEA BREEZES. COVERAGE ACROSS NORTH CENTRAL FL WILL BE
ISOLATED TO WIDELY SCATTERED, WITH ANY CONVECTION THAT MANAGES TO
DEVELOP LIKELY BEING BRIEF IN NATURE AND REMAINING RATHER
PEDESTRIAN IN INTENSITY. THE INLAND MOVING ATLANTIC SEA BREEZE
WILL BRING AN INCREASE IN CUMULUS AND MARINE STRATOCUMULUS CLOUDS
THIS AFTERNOON, BUT PLENTY OF SUNSHINE THIS MORNING, THE DRY AIR
MASS IN PLACE, AND A LOOSE LOCAL PRESSURE GRADIENT WILL ALLOW
HIGHS TO SOAR TO THE LOWER 90S FOR LOCATIONS WEST OF THE I-95
CORRIDOR, WHILE AN ONSHORE BREEZE TODAY KEEPS COASTAL HIGHS MOSTLY
IN THE UPPER 80S. DEWPOINTS WILL REMAIN IN THE 60S ACROSS INLAND
SOUTHEAST GA AND THE SUWANNEE VALLEY, WHILE VALUES RISE INTO THE
70S ACROSS COASTAL LOCATIONS AND AREAS SOUTH OF I-10 THIS
AFTERNOON AS THE ATLANTIC SEA BREEZE BOUNDARY PUSHES INLAND, WHERE
HEAT INDEX VALUES MAY CLIMB TO THE UPPER 90S TO AROUND 100.
ANY ISOLATED, LOW-TOPPED CONVECTION THAT DEVELOPS ALONG COLLIDING
MESOSCALE BOUNDARIES ACROSS NORTH CENTRAL FL LATER TODAY WILL
QUICKLY DISSIPATE EARLY THIS EVENING. FAIR SKIES, DECOUPLING WINDS
AT INLAND LOCATIONS, A SUBSIDENT AIR MASS, AND GRADUALLY
INCREASING LOW LEVEL MOISTURE VALUES SHOULD PROMOTE PATCHY FOG
FORMATION AT INLAND LOCATIONS EARLY ON FRIDAY MORNING. LOWS WILL
FALL TO THE UPPER 60S FOR INLAND SOUTHEAST GA AND THE SUWANNEE
VALLEY, WHILE A LIGHT ONSHORE BREEZE KEEPS COASTAL LOWS IN THE LOW
TO MID 70S.
SHORT TERM
(FRIDAY THROUGH SATURDAY NIGHT)
ISSUED AT 159 AM EDT THU SEP 4 2025
AT THE SURFACE, A RIDGE AXIS WILL LAY ACROSS SE GA, WHILE A
LEFTOVER FRONTAL ZONE REMAINS STALLED ACROSS SOUTHERN FL TO END
THE WEEK. BETWEEN THOSE FEATURES AN ONSHORE BREEZE WILL CONTINUE
LOCALLY. MEANWHILE, DE-AMPLIFYING LONGWAVE TROUGHING WILL ALLOW
TEMPS TO HEAT UP ONCE AGAIN WITH READINGS REBOUNDING BACK INTO THE
LOW 90S INLAND WITH UPPER 80S AT THE COAST EACH AFTERNOON.
INCREASING DEW POINTS WILL BOOST HEAT INDEX VALUES BACK INTO THE
TRIPLE DIGITS ACROSS NE FL BY FRIDAY.
NOT MUCH CHANGE WITH RAIN CHANCES. THE DRY AIRMASS WITH
PRECIPITABLE WATER BELOW THE 25TH PERCENTILE WILL KEEP RAIN
CHANCES MINIMAL. HOWEVER, SOME FRINGE MOISTURE ALONG THE NORTHERN
SIDE STALLED FRONTAL ZONE ACROSS SOUTHERN FL WILL BEGIN TO LIFT
ACROSS NORTH- CENTRAL FL FRIDAY AND THEN TOWARD I-10 BY SATURDAY.
THE GRADUAL INCREASE IN MOISTURE COUPLED WITH DIURNAL HEATING AND
SEA BREEZE CONVERGENCE, COULD PRODUCE ISOLATED TO WIDELY SCATTERED
LOW-TOPPED SHOWERS EACH AFTERNOON. LITTLE CHANCE FOR
THUNDERSTORMS, BUT THE BEST CHANCES FOR AN ISOLATED STORM WILL BE
ACROSS NORTH-CENTRAL FL WHERE UPDRAFTS MAY ENTRAIN LESS DRY AIR.
LONG TERM
(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 159 AM EDT THU SEP 4 2025
ANOTHER UNSEASONABLE COOL FRONT WILL BE DRAGGED TOWARD THE REGION
BY EARLY NEXT WEEK AS BROAD LONGWAVE TROUGHING DIGS SOUTHWARD
BACK TOWARD THE SOUTHEASTERN US. POOLING MOISTURE ALONG THE FRONT
WILL INCREASE SCATTERED SHOWER AND THUNDERSTORM CHANCES BY MONDAY
AS PRECIPITABLE WATER NEAR RISES TO NEARLY TWO INCHES, ACCORDING
TO LREF PLUMES.
THE FOLLOW UP SURFACE HIGH SHOULD SET US UP WITH ANOTHER "MINI"
NOR'EASTER ONCE AGAIN. THE SURGE AND DURATION OF THE EVENT LOOKS
QUITE SIMILAR TO THE LAST FEW DAYS. ANTICIPATE UNSETTLED, GLOOMY
AND COOLER CONDITIONS AS STRATOCUMULUS AND CONVERGENT BANDS OF
SHOWERS PUSH INTO THE COAST. FLOOD RISK INITIALLY SHOULD BE LOW
GIVEN THE SEVERAL DAYS OF PRECEDING DRY CONDITIONS.
AVIATION
(06Z TAFS)
ISSUED AT 159 AM EDT THU SEP 4 2025
PERIODS OF IFR VISIBILITIES ARE EXPECTED OVERNIGHT AT VQQ.
OTHERWISE, VFR CONDITIONS WILL PREVAIL AT THE REGIONAL TERMINALS.
A BRIEF PERIOD OF MVFR CEILINGS BETWEEN 2,000-3,000 FEET WILL BE
POSSIBLE AFTER SUNRISE AT THE SGJ AND SSI COASTAL TERMINALS, BUT
CONFIDENCE WAS TOO LOW TO INDICATE ANYTHING OTHER THAN SCATTERED
COVERAGE AT THIS TIME. A FEW SHOWERS MAY DEVELOP NEAR THE GNV
TERMINAL AFTER 22Z THURSDAY THROUGH AROUND 02Z FRIDAY AS THE
ATLANTIC AND GULF SEA BREEZES COLLIDE NEAR OR JUST EAST OF
INTERSTATE 75. COVERAGE SHOULD BE SPARSE AND DURATION OF ANY
SHOWERS SHOULD BE BRIEF, AND CONFIDENCE WAS TOO LOW TO INDICATE
ANY VICINITY SHOWER COVERAGE AT THIS TIME. OTHERWISE, BROKEN VFR
CEILINGS OF 3,500 - 4,500 FEET ARE EXPECTED TO DEVELOP AT THE
TERMINALS ON THURSDAY AFTERNOON AS SEA BREEZES PROGRESS INLAND.
FOG AND LOW STRATUS CEILINGS WILL LIKELY DEVELOP AFTER THE
CONCLUSION OF THIS TAF PERIOD AT VQQ DURING THE OVERNIGHT HOURS ON
THURSDAY NIGHT, WITH FOG POTENTIALLY EXPANDING TO THE GNV TERMINAL
DURING THE PREDAWN HOURS ON FRIDAY.
MARINE
ISSUED AT 159 AM EDT THU SEP 4 2025
WEAK HIGH PRESSURE SITUATED ALONG THE SOUTHEASTERN SEABOARD WILL
SHIFT EASTWARD BU TONIGHT. MEANWHILE, A FRONTAL BOUNDARY CURRENTLY
STALLED NEAR THE FLORIDA KEYS WILL LIFT SLOWLY NORTHWARD THROUGH THE
FLORIDA PENINSULA ON THURSDAY AND FRIDAY, WITH ANOTHER WEAK LOW
PRESSURE CENTER DEVELOPING ALONG THIS FRONT EAST OF CAPE CANAVERAL.
THIS FEATURE WILL LIKELY MAINTAIN GENERALLY LIGHT ONSHORE WINDS
ACROSS OUR LOCAL WATERS THROUGH THE WEEKEND. A FRONTAL BOUNDARY WILL
THEN APPROACH OUR REGION FROM THE NORTHWEST ON SUNDAY, WITH THIS
FRONT THEN STALLING ACROSS OUR LOCAL WATERS ON MONDAY, BRINGING
INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS. ONSHORE WINDS WILL
INCREASE AND SEAS WILL BUILD EARLY NEXT WEEK AS STRONG HIGH PRESSURE
BUILDING OVER NEW ENGLAND WEDGES DOWN THE SOUTHEASTERN SEABOARD.
RIP CURRENTS: A LINGERING EAST-NORTHEASTERLY OCEAN SWELL WILL
COMBINE WITH ONSHORE WINDS TO KEEP A MODERATE RIP CURRENT RISK IN
PLACE AT AREA BEACHES FROM TODAY THROUGH THE UPCOMING WEEKEND. A
HIGH RISK IS LIKELY BY EARLY NEXT WEEK AS ONSHORE WINDS STRENGTHEN
AND SURF GRADUALLY BUILDS.
FIRE WEATHER
ISSUED AT 159 AM EDT THU SEP 4 2025
AN UNSEASONABLY DRY AIR MASS WILL REMAIN IN PLACE FOR LOCATIONS
ALONG AND NORTH OF THE INTERSTATE 10 CORRIDOR THROUGH FRIDAY.
SURFACE AND TRANSPORT WINDS WILL BECOME EASTERLY ALONG THE I-95
CORRIDOR AND SOUTHEASTERLY FURTHER INLAND ON THURSDAY AND FRIDAY,
WITH BREEZY SURFACE WINDS DEVELOPING AT COASTAL LOCATIONS BY EARLY
AFTERNOON BOTH DAYS. ELEVATED MIXING HEIGHTS WILL AGAIN YIELD
FAIR TO GOOD DAYTIME DISPERSION VALUES.
HYDROLOGY
ISSUED AT 159 AM EDT THU SEP 4 2025
ON THE HYDRO SIDE, NORTHEASTERLY WIND SURGE WILL TRAP
TIDEWATER IN THE UPPER ST JOHNS RIVER POTENTIALLY ELEVATING HIGH
TIDE SOUTH OF JACKSONVILLE.
CLIMATE
ISSUED AT 159 AM EDT THU SEP 4 2025
RECORD LOWS FOR THURSDAY AT OUR DESIGNATED CLIMATE SITES:
JACKSONVILLE 66/2023
GAINESVILLE 62/1891
ALMA, GA 59/1954
CRAIG AIRPORT 68/1998
PRELIMINARY POINT TEMPS/POPS
AMG 90 68 93 68 / 0 0 0 0
SSI 87 72 88 75 / 0 0 0 0
JAX 90 70 91 72 / 10 0 10 0
SGJ 88 76 89 75 / 20 10 20 10
GNV 93 71 94 70 / 10 0 20 0
OCF 90 72 92 73 / 20 0 30 0
JAX WATCHES/WARNINGS/ADVISORIES
FL...COASTAL FLOOD ADVISORY UNTIL 5 AM EDT SATURDAY FOR FLZ038-132-
137-633.
GA...NONE.
AM...NONE.
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