247
FXUS62 KJAX 200857
AFDJAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
457 AM EDT SUN SEP 20 2026
KEY MESSAGES
FOR THE LATEST NE FL AND SE GA DAILY KEY MESSAGES PLEASE VISIT:
HTTPS:/WWW.WEATHER.GOV/MEDIA/JAX/BRIEFINGS/NWS-JAX-BRIEFING.PDF
- SCATTERED TO NUMEROUS MAINLY AFTERNOON AND EARLY EVENING
THUNDERSTORMS CONTINUE THROUGH WEDNESDAY.
- ISOLATED STRONG STORMS AND LOCALLY HEAVY RAINFALL POSSIBLE.
- MODERATE RIP CURRENT RISK CONTINUES THROUGH MIDWEEK AT ALL
AREA BEACHES.
- STRENGTHENING NORTHEASTERLY WINDS WILL BRING INCREASING MARINE
HAZARDS TO COASTAL LOCATIONS ON THURSDAY AND FRIDAY.
- COOLER TEMPERATURES ARE FORECAST LATER THIS WEEK AND INTO NEXT
WEEKEND AREA-WIDE.
- MINOR COASTAL FLOODING POSSIBLE AROUND TIMES OF HIGH TIDE LATE
THIS WEEK AND NEXT WEEKEND.
NEAR TERM /THROUGH TONIGHT/
MAIN HIGHLIGHTS:
- SCATTERED TO NUMEROUS MAINLY AFTERNOON AND EARLY EVENING
THUNDERSTORMS TODAY.
- ISOLATED STRONG STORMS POSSIBLE AT INLAND LOCATIONS LATE THIS
AFTERNOON AND EARLY THIS EVENING.
- MODERATE RIP CURRENT RISK CONTINUES AT ALL AREA BEACHES.
EARLY MORNING SURFACE ANALYSIS DEPICTS A TROUGH OVER THE SPINE
OF THE FL PENINSULA, WITH A WEAK PRESSURE PATTERN OTHERWISE
PREVAILING ACROSS OUR REGION. MEANWHILE, HIGH PRESSURE (1024
MILLIBARS) POSITIONED OVER COASTAL NEW ENGLAND HAS PUSHED A
"BACKDOOR" FRONTAL BOUNDARY SOUTHWARD ACROSS THE SOUTHERN
APPALACHIANS, WITH THIS BOUNDARY EXTENDING EASTWARD TO THE
COASTAL CAROLINA REGION. ALOFT...A TROPICAL UPPER TROPOSPHERIC
TROUGH (TUTT) WAS NEARLY STATIONARY AS IT SPINS JUST WEST OF THE
TAMPA BAY REGION. OTHERWISE, "HEAT WAVE" RIDGING OVER EASTERN
TEXAS, THE OZARKS, AND THE LOWER MISSISSIPPI VALLEY WAS IN THE
PROCESS OF WEAKENING AS TROUGHING OVER THE ROCKIES AND THE
SOUTHERN PLAINS PROGRESSES SLOWLY EASTWARD. LATEST GOES-EAST
DERIVED TOTAL PRECIPITABLE WATER IMAGERY INDICATES THAT PWATS
REMAIN ABOVE LATE SEPTEMBER CLIMATOLOGY ACROSS OUR AREA, WITH
VALUES IN THE 1.8 - 2 INCH RANGE. SCATTERED CONVECTION
ASSOCIATED WITH THE AFOREMENTIONED TUTT FEATURE WAS BLOSSOMING
OVER THE OFFSHORE ATLANTIC WATERS. PATCHES OF MOSTLY MID AND
HIGH ALTITUDE CLOUD COVER WERE DRIFTING ACROSS OUR SKIES, WITH
TEMPERATURES AND DEWPOINTS IN THE 70S AREA-WIDE AS OF 09Z.
A RATHER STAGNANT WEATHER PATTERN IS EXPECTED ACROSS OUR AREA
TODAY AS THE TUTT FEATURE AND ITS ACCOMPANYING SURFACE TROUGH
REMAIN STATIONARY NEAR TAMPA BAY AND OVER THE FL PENINSULA,
RESPECTIVELY. LOW LEVEL EAST-NORTHEASTERLY FLOW WILL PREVAIL,
WITH A MOIST AND UNSTABLE ATMOSPHERE PROMOTING SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS THAT WILL PROGRESS WESTWARD.
SCATTERED CONVECTION OVER THE ATLANTIC WATERS EARLY THIS MORNING
SHOULD EDGE TOWARDS COASTAL LOCATIONS AS THE MORNING
PROGRESSES, WITH ACTIVITY THEN INCREASING IN COVERAGE AND
INTENSITY THIS AFTERNOON AS THE ATLANTIC SEA BREEZE PUSHES
SHOWERS AND THUNDERSTORMS WEST OF THE I-95 CORRIDOR BY THE MID
TO LATE AFTERNOON HOURS. RELATIVELY COOL TEMPERATURES ALOFT,
SUPPLIED BY THE TUTT FEATURE, SHOULD ALLOW FOR A FEW STORMS TO
"PULSE" AND BECOME STRONG TO THE WEST OF THE I-95 CORRIDOR LATER
THIS AFTERNOON AND POSSIBLY CONTINUING IN THE SUWANNEE VALLEY
AND PORTIONS OF INTERIOR SOUTHEAST GA THIS EVENING, WITH
STRONGER STORMS BEING CAPABLE OF PRODUCING DOWNBURST WINDS OF
35-45 MPH, FREQUENT LIGHTING STRIKES, HEAVY DOWNPOURS, AND
POSSIBLY SMALL HAIL AS WELL. BREAKS IN THE MID AND HIGH ALTITUDE
CLOUD COVER THIS MORNING SHOULD ALLOW HIGHS TO CLIMB TO THE
UPPER 80S AND LOWER 90S, WITH HEAT INDEX VALUES PEAKING AROUND
100 BEFORE CONVECTIVE COVERAGE AND CLOUD COVER INCREASES LATER
THIS AFTERNOON.
CONVECTION MAY LINGER EARLY THIS EVENING ACROSS THE SUWANNEE
VALLEY AND INLAND SOUTHEAST GA, WITH THIS ACTIVITY THEN
SHIFTING WEST OF THE ALAPAHA AND SUWANNEE RIVERS BEFORE
MIDNIGHT. CONVERGENT LOW LEVEL EAST-NORTHEASTERLY FLOW AND
PLENTY OF AVAILABLE MOISTURE SHOULD ALLOW FOR WIDELY SCATTERED
SHOWERS AND POSSIBLY A FEW EMBEDDED THUNDERSTORMS TO DEVELOP AND
BLOSSOM OVER THE ATLANTIC WATERS AGAIN OVERNIGHT, AND THIS
ACTIVITY SHOULD APPROACH COASTAL SOUTHEAST GA AND PORTIONS OF
COASTAL NORTHEAST FL BEFORE SUNRISE ON MONDAY. PATCHY FOG
FORMATION WILL ALSO BE POSSIBLE AT INLAND LOCATIONS TOWARDS
SUNRISE, MAINLY WEST OF THE U.S. HIGHWAY 301 CORRIDOR. LOWS WILL
GENERALLY FALL TO THE 70-75 DEGREE RANGE ACROSS OUR AREA LATER
TONIGHT.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/
MAIN HIGHLIGHTS THIS PERIOD:
- SCATTERED TO NUMEROUS MAINLY AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EXPECTED.
- A FEW STRONG STORMS WITH LOCALLY HEAVY RAINFALL ARE POSSIBLE,
ESPECIALLY ON MONDAY.
THE TUTT FEATURE AND ITS ACCOMPANYING SURFACE TROUGH WILL MOVE
SLOWLY NORTHEASTWARD ACROSS OUR AREA ON MONDAY, WITH WEAK
CYCLOGENESIS THEN POSSIBLE OFF THE SOUTHEASTERN U.S. SEABOARD ON
TUESDAY AS THESE FEATURES LIFT SLOWLY AWAY FROM OUR REGION.
LOW- LEVEL ONSHORE WINDS WILL CONTINUE, AND CONVECTION MAY GET
AN EARLY START ON MONDAY AT COASTAL LOCATIONS AND ALONG THE I-95
CORRIDOR AS TEMPERATURES ALOFT CONTINUE TO GRADUALLY COOL IN
ASSOCIATION WITH THE TUTT MOVING OVERHEAD. ACTIVITY WILL THEN
PROGRESS SLOWLY INLAND AS THE DAY CONTINUES, WITH A FEW STRONG
STORMS POSSIBLE FURTHER INLAND. SLOW STORM MOTION COULD ALSO
RESULT IN LOCALLY HEAVY RAINFALL AMOUNTS. HIGHS ON MONDAY SHOULD
AGAIN CLIMB TO THE UPPER 80S AND LOWER 90S, WITH PLENTY OF
HUMIDITY ALLOWING HEAT INDICES TO AGAIN PEAK AROUND OR JUST
ABOVE 100 AT INLAND LOCATIONS.
CONVECTION SHOULD CONTINUE TO SHIFT WEST OF OUR AREA DURING THE
EVENING HOURS, WITH NOCTURNAL ACTIVITY FLARING OVER THE ATLANTIC
WATERS THEN EDGING TOWARDS COASTAL LOCATIONS BY EARLY TUESDAY
MORNING. LOW LEVEL FLOW WILL BECOME MORE SOUTHERLY BY TUESDAY
AFTERNOON AS THE TUTT FEATURE AND DEVELOPING SURFACE LOW
PROGRESS AWAY FROM OUR REGION, WITH PLENTY OF MOISTURE LEFT
BEHIND ALLOWING FOR SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS TO DEVELOP ALONG INLAND MOVING SEA BREEZES ON
TUESDAY AFTERNOON. TEMPERATURES ALOFT WILL NOT BE QUITE AS COOL
ON TUESDAY, BUT HIGHS REACHING THE UPPER 80S AND LOWER 90S COULD
STILL PROVIDE ENOUGH INSTABILITY FOR STORMS TO "PULSE" AS
MESOSCALE BOUNDARIES COLLIDE DURING THE AFTERNOON AND EARLY
EVENING HOURS AT INLAND LOCATIONS, WHERE ISOLATED STRONG STORMS
CONTAINING BRIEFLY GUSTY WINDS, FREQUENT LIGHTNING STRIKES, AND
SLOW MOVING, LOCALLY HEAVY DOWNPOURS WILL BE POSSIBLE. ACTIVITY
WILL DISSIPATE BY THE MID TO LATE EVENING HOURS AT INLAND
LOCATIONS, WITH LATE NIGHT CONVECTION AGAIN POSSIBLY IMPACTING
COASTAL LOCATIONS BEFORE SUNRISE ON WEDNESDAY. LOWS WILL REMAIN
MOSTLY IN THE LOW AND MID 70S ACROSS OUR AREA.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
MAIN HIGHLIGHTS THIS PERIOD:
- SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS CONTINUE ON
WEDNESDAY.
- STRENGTHENING NORTHEASTERLY WINDS WILL BRING INCREASING MARINE
HAZARDS TO COASTAL LOCATIONS ON THURSDAY AND FRIDAY.
- COOLER TEMPERATURES ARE FORECAST LATER THIS WEEK AND INTO NEXT
WEEKEND AREA-WIDE.
- MINOR COASTAL FLOODING POSSIBLE AROUND TIMES OF HIGH TIDE LATE
THIS WEEK AND NEXT WEEKEND.
TROUGHING WILL DIG OVER THE EASTERN HALF OF THE NATION DURING
THE LONG TERM PERIOD, WITH STRONG SURFACE HIGH PRESSURE
BUILDING OVER SOUTHEASTERN CANADA AND NEW ENGLAND WEDGING DOWN
THE SOUTHEASTERN SEABOARD ON WEDNESDAY AFTERNOON AND EVENING.
THIS WEATHER PATTERN WILL DRIVE A COLD FRONT SOUTHWARD INTO OUR
REGION, WITH DEEP MOISTURE POOLING DOWNSTREAM OF THIS FRONT
ACROSS OUR AREA. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS
SHOULD CONTINUE ACROSS OUR AREA ON WEDNESDAY, ESPECIALLY AS THE
FRONT APPROACHES DURING THE AFTERNOON AND EVENING HOURS. A FEW
STRONG STORMS AND LOCALLY HEAVY RAINFALL WILL CONTINUE TO BE
POSSIBLE, WITH ACTIVITY LIKELY CONCENTRATING ACROSS INLAND
PORTIONS OF NORTHEAST AND NORTH CENTRAL FL DURING THE AFTERNOON
AND EVENING HOURS AS OUR LOCAL PRESSURE GRADIENT TIGHTENS,
CREATING BREEZY NORTHEASTERLY WINDS ALONG THE I- 95 CORRIDOR BY
THE LATE AFTERNOON HOURS. HIGHS WILL RANGE FROM THE MID 80S AT
COASTAL LOCATIONS TO AROUND 90 AT INLAND LOCATIONS THROUGH
TONIGHT.
SHOWERS AND THUNDERSTORMS MAY CONTINUE ON WEDNESDAY NIGHT ACROSS
NORTHEAST AND NORTH CENTRAL FL AS THE FRONTAL BOUNDARY SHIFTS
SOUTHWARD THROUGH OUR AREA, WITH BREEZY NORTHEASTERLY WINDS
POTENTIALLY PRODUCING WAVES OF COASTAL SHOWERS AND POSSIBLY A
FEW EMBEDDED THUNDERSTORMS THROUGHOUT THE NIGHT ALONG THE I-95
CORRIDOR. COOL AIR ADVECTION IN THE WAKE OF THE FRONTAL PASSAGE
COULD DROP LOWS TO THE UPPER 60S DESPITE AN ABUNDANCE OF CLOUD
COVER ACROSS SOUTHEAST GA ON WEDNESDAY NIGHT, WITH LOW TO MID
70S PERSISTING ELSEWHERE.
STRONG HIGH PRESSURE WILL PERSIST OVER NEW ENGLAND LATE THIS
WEEK, WITH LOW PRESSURE INITIALLY OFFSHORE OF THE SOUTHEASTERN
STATES THEN POTENTIALLY STRENGTHENING OFF THE MID-ATLANTIC
COAST. THIS WEATHER PATTERN WILL KEEP BREEZY NORTHEASTERLY WINDS
IN PLACE ON THURSDAY ALONG THE I-95 CORRIDOR, AND THESE WINDS
MAY SHIFT TO NORTHERLY BY FRIDAY AND SATURDAY, POTENTIALLY
USHERING IN A COOLER AND DRIER AIR MASS INTO OUR REGION. GUSTY
ONSHORE WINDS ON THURSDAY SHOULD STILL PROVIDE COASTAL SHOWERS
FOR COASTAL NORTHEAST FL, BUT RAIN CHANCES COULD THEN DECREASE
BY FRIDAY AND SATURDAY DEPENDING ON HOW THE COASTAL STORM
EVOLVES OFF THE MID-ATLANTIC COAST. HIGHS SHOULD REMAIN IN THE
LOW AND MID 80S FROM THURSDAY ONWARD AREA-WIDE, AND LOWS COULD
FALL INTO THE LOWER 60S FOR INLAND SOUTHEAST GA AND THE MID TO
UPPER 60S ELSEWHERE INLAND BY LATE THIS WEEK AND INTO NEXT
WEEKEND. COASTAL LOWS MAY FALL TO AROUND 70 AS WINDS BECOME MORE
NORTHERLY AND COOL AIR ADVECTION CONTINUES LATER THIS WEEK AND
INTO NEXT WEEKEND.
ASTRONOMICAL TIDES WILL BE ON THE RISE LATER THIS WEEK DUE TO
THE UPCOMING FULL "HARVEST" MOON, AND MINOR COASTAL FLOODING
DURING TIMES OF HIGH TIDE ALONG THE ATLANTIC COAST AND WITHIN
THE ST. JOHNS RIVER BASIN WILL BE A POSSIBILITY LATER THIS WEEK
AND INTO NEXT WEEKEND, ALL DEPENDING ON THE STRENGTH AND
POSITIONING OF COASTAL LOW PRESSURE TO OUR NORTH AND THE
TRAJECTORY OF SURFACE WINDS.
AVIATION /06Z SUNDAY THROUGH 06Z MONDAY/
VFR CONDITIONS WILL PREVAIL AT THE REGIONAL TERMINALS THROUGH AT
LEAST 12Z. SHOWERS AND POSSIBLY A FEW EMBEDDED THUNDERSTORMS
DEVELOPING OVER THE NEAR SHORE ATLANTIC WATERS MAY PROVIDE FOR
CONVECTION NEAR THE SSI AND SGJ COASTAL TERMINALS AFTER 12Z.
HOWEVER, CONFIDENCE REMAINS TOO LOW TO INDICATE ANYTHING OTHER
THAN VICINITY COVERAGE AT THIS TIME THROUGH AROUND 16Z. SHOWERS
AND THUNDERSTORMS DEVELOPING ALONG THE INLAND MOVING ATLANTIC
SEA BREEZE BOUNDARY WILL PROGRESS WESTWARD ON SUNDAY AFTERNOON.
CONFIDENCE WAS HIGH ENOUGH TO INDICATE PREVAILING VICINITY
THUNDERSTORMS AT GNV AND VQQ, WITH VICINITY SHOWERS MAINTAINED
ELSEWHERE. PROB30 GROUPS FOR BRIEF SURFACE WIND GUSTS AROUND 25
KNOTS AND MVFR CONDITIONS DURING HEAVIER DOWNPOURS WERE INCLUDED
AT EACH TERMINAL THROUGH AROUND 00Z. . LIGHT NORTHWEST TO
NORTHERLY SURFACE WINDS WILL DEVELOP TOWARDS SUNRISE, FOLLOWED
BY WINDS SHIFTING TO NORTHEASTERLY AT 5-10 KNOTS BY 16Z AND THEN
EASTERLY AROUND 10 KNOTS BY 20Z. SURFACE WINDS WILL THEN SHIFT
TO SOUTHEASTERLY WITH DIMINISHING SPEEDS AFTER 01Z MONDAY.
MARINE
SURFACE TROUGHING AND A DISTURBANCE ALOFT LOCATED JUST WEST OF
TAMPA BAY WILL REMAIN NEARLY STATIONARY THROUGH TONIGHT BEFORE
LIFTING SLOWLY NORTH-NORTHEASTWARD ACROSS OUR LOCAL WATERS BY
MONDAY NIGHT AND TUESDAY. SCATTERED SHOWERS AND THUNDERSTORMS
WILL REMAIN POSSIBLE THROUGH TONIGHT, WITH COVERAGE THEN
INCREASING FROM MONDAY THROUGH AT LEAST THURSDAY. EAST-
NORTHEASTERLY WINDS WILL PREVAIL THROUGH TUESDAY, WITH SPEEDS
AND SEAS REMAINING BELOW CAUTION LEVELS OUTSIDE OF THUNDERSTORM
ACTIVITY. STRONG HIGH PRESSURE BUILDING OVER SOUTHEASTERN CANADA
AND NEW ENGLAND ON TUESDAY WILL BEGIN TO WEDGE DOWN THE
SOUTHEASTERN SEABOARD ON WEDNESDAY AFTERNOON AND EVENING,
CREATING A SURGE OF NORTHEASTERLY WINDS THAT WILL LIKELY CREATE
SMALL CRAFT ADVISORY CONDITIONS ACROSS OUR LOCAL WATERS
BY THURSDAY AND FRIDAY.
RIP CURRENTS: PERSISTENT EAST-NORTHEASTERLY WINDS WILL KEEP A
LOWER-END MODERATE RISK IN PLACE THROUGH MIDWEEK AT ALL AREA
BEACHES. A SURGE OF STRENGTHENING NORTHEASTERLY WINDS AND
BUILDING BREAKER HEIGHTS WILL ARRIVE ON WEDNESDAY EVENING, AND
A HIGH RISK IS LIKELY AT ALL AREA BEACHES ON THURSDAY AND
FRIDAY, POSSIBLY CONTINUING INTO NEXT WEEKEND.
FIRE WEATHER
- LOW DAYTIME DISPERSION VALUES FOR COASTAL SOUTHEAST GA AND
PORTIONS OF COASTAL NORTHEAST FL TODAY.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP EACH DAY THROUGH THURSDAY, MAINLY DURING THE AFTERNOON
AND EVENING HOURS. ACTIVITY WILL GENERALLY PROGRESS FROM EAST TO
WEST, WITH SHOWERS AND THUNDERSTORMS CONCENTRATING ALONG THE
INTERSTATE 10 CORRIDOR, THE SUWANNEE VALLEY, AND THE OKEFENOKEE
SWAMP THIS AFTERNOON THROUGH EARLY THIS EVENING. OTHERWISE,
EAST- NORTHEASTERLY SURFACE AND TRANSPORT WINDS WILL PREVAIL
THROUGH TUESDAY, FOLLOWED BY GRADUALLY STRENGTHENING
NORTHEASTERLY SURFACE AND TRANSPORT WINDS ON WEDNESDAY, WITH
STRONGER SPEEDS THEN FORECAST ON THURSDAY AND FRIDAY. LIGHTER
SPEEDS TODAY WILL YIELD MARGINALLY LOW DAYTIME DISPERSION VALUES
FOR COASTAL SOUTHEAST GEORGIA AND PORTIONS OF COASTAL NORTHEAST
FLORIDA, WITH GENERALLY POOR VALUES FORECAST ELSEWHERE, EXCEPT
FAIR VALUES FOR NORTH CENTRAL FLORIDA. POOR TO FAIR DAYTIME
DISPERSION VALUES WILL CONTINUE THROUGH MIDWEEK, EXCEPT FOR GOOD
VALUES ACROSS INLAND SOUTHEAST GEORGIA ON WEDNESDAY.
FOG POTENTIAL...PATCHY FOG FORMATION IS POSSIBLE ACROSS INLAND
PORTIONS OF SOUTHEAST GEORGIA, THE SUWANNEE VALLEY AND INLAND
PORTIONS OF NORTH CENTRAL FLORIDA DURING THE PREDAWN AND EARLY
MORNING HOURS ON SUNDAY AND MONDAY.
PRELIMINARY POINT TEMPS/POPS
AMG 91 70 91 70 / 40 20 30 0
SSI 87 75 88 74 / 30 30 40 20
JAX 89 71 90 72 / 50 20 50 10
SGJ 87 75 88 74 / 30 10 40 20
GNV 89 71 91 71 / 60 30 70 10
OCF 90 71 91 72 / 50 20 70 20
JAX WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GA...NONE.
MARINE...NONE.
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