342
FXUS62 KJAX 091820
AFDJAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
220 PM EDT SUN AUG 9 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 THUNDERSTORMS THROUGH THIS EVENING.
ISOLATED STRONG STORMS WITH WIND GUSTS OF 40-50 MPH, FREQUENT
LIGHTNING, AND TORRENTIAL DOWNPOURS ARE POSSIBLE.
- SLOW MOVING DOWNPOURS WILL INCREASE THE THREAT FOR LOCALIZED
FLOODING, ESPECIALLY AT URBAN AND NORMALLY FLOOD PRONE
LOCATIONS.
- HIGH RISK OF RIP CURRENTS AT NORTHEAST FL BEACHES THIS
AFTERNOON. MODERATE RISK AT THE SOUTHEAST GA BEACHES.
- ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS
FROM MONDAY THROUGH SATURDAY.
- HEAT AND HUMIDITY BUILDS THIS WEEK. HEAT ADVISORIES POSSIBLE
EACH DAY FROM TUESDAY THROUGH FRIDAY.
NEAR TERM /THROUGH TONIGHT/
MAIN HIGHLIGHTS:
- SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS THROUGH THIS
EVENING.
- ISOLATED STRONG STORMS ARE POSSIBLE, WITH WIND GUSTS OF 40-50
MPH, FREQUENT LIGHTNING STRIKES, AND HEAVY DOWNPOURS.
- SLOW MOVING DOWNPOURS WILL INCREASE THE THREAT FOR LOCALIZED
FLOODING, ESPECIALLY AT URBAN AND NORMALLY FLOOD PRONE
LOCATIONS.
- MODERATE TO HIGH RISK OF RIP CURRENTS AT AREA BEACHES.
AFTERNOON SURFACE ANALYSIS DEPICTS A SURFACE TROUGH POSITIONED
ALONG THE CAROLINA COAST THAT EXTENDS SOUTHWESTWARD ACROSS
SOUTHEAST GA, WHILE ATLANTIC HIGH PRESSURE (1023 MILLIBARS) WAS
BUILDING WESTWARD ACROSS NORTH CENTRAL FL. ALOFT...DEEP-LAYERED
ATLANTIC RIDGING WAS EXTENDING ITS AXIS WESTWARD ACROSS THE FL
PENINSULA AND INTO THE EASTERN GULF. LATEST GOES-EAST DERIVED
TOTAL PRECIPITABLE WATER IMAGERY INDICATES THAT DEEP TROPICAL
MOISTURE REMAINS IN PLACE ACROSS ALL OF SOUTHEAST GA AND
NORTHEAST FL, WHERE PWATS OF 2.1 - 2.3 INCHES PREVAIL. A
SLIGHTLY DRIER AIR MASS ASSOCIATED WITH THE ATLANTIC RIDGE AXIS
HAS ADVECTED NORTHWARD INTO NORTH CENTRAL FL, WHERE PWATS RANGED
FROM 1.8 - 2 INCHES. SLOW MOVING CONVECTION CONTINUES TO EXPAND
AND BACKBUILD ALONG THE TROUGH AXIS FROM THE ALONG THE I-95 AND
U.S.-301 CORRIDORS IN SOUTHEAST GA, WITH ISOLATED CONVECTION
DEVELOPING ALONG THE I-95 AND I-10 CORRIDORS IN NORTHEAST FL AND
THE SUWANNEE VALLEY. A HEALTHY CUMULUS FIELD WAS OTHERWISE
BUILDING ACROSS OUR AREA, WITH TEMPERATURES AT 18Z RANGING FROM
THE LOWER 90S INLAND TO THE UPPER 80S AT COASTAL LOCATIONS, WITH
DEWPOINTS GENERALLY IN THE 70S INLAND AND AROUND 80 AT COASTAL
LOCATIONS, CREATING HEAT INDEX VALUES MOSTLY IN THE 100-105
DEGREE RANGE.
GIVEN PLENTY OF TROPICAL MOISTURE IN PLACE, WE EXPECT CONVECTION
TO GRADUALLY EXPAND IN COVERAGE AND INTENSITY ALONG THE I-95
AND U.S.- 301 CORRIDORS THROUGH MID-AFTERNOON, WITH ACTIVITY
TENDING TO BACKBUILD ALONG THE LINGERING TROUGH AXIS THAT
EXTENDS INTO THE OKEFENOKEE SWAMP IN SOUTHEAST GA. CONVECTIVE
OUTFLOWS WILL PUSH SOUTHWARD AND SHOULD THEN COLLIDE WITH OTHER
MESOSCALE BOUNDARIES TO DEVELOP SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS INTO THE EARLY EVENING HOURS ACROSS THE REST
OF NORTHEAST AND NORTH CENTRAL FL. COLLIDING MESOSCALE
BOUNDARIES SHOULD ALLOW FOR AT LEAST A FEW STORMS TO PULSE AND
BECOME STRONG, WITH WET MICROBURST POTENTIAL THAT COULD PRODUCE
40-50 MPH WINDS, ALONG WITH FREQUENT LIGHTNING STRIKES AND
TORRENTIAL DOWNPOURS. LOCATIONS ALONG THE I-10 AND U.S.- 301
CORRIDORS IN NORTHEAST FL MAY HAVE A SLIGHTLY HIGHER POTENTIAL
FOR STRONGER STORMS LATER THIS AFTERNOON AS MESOSCALE BOUNDARIES
CONVERGE OVER THESE AREAS. INLAND HIGHS SHOULD REACH THE LOW
AND MID 90S AT MOST LOCATIONS, WITH HEAT INDEX VALUES PEAKING IN
THE 103-107 DEGREE RANGE, OR JUST BELOW LOCAL HEAT ADVISORY
CRITERIA. COASTAL HIGHS WILL REACH THE UPPER 80S TO AROUND 90
BEFORE THE SEA BREEZE PUSHES FURTHER INLAND.
CONVECTIVE OUTFLOWS MAY PUSH CONVECTION TOWARDS THE I-75
CORRIDOR IN THE SUWANNEE VALLEY AND INTERIOR PORTIONS OF NORTH
CENTRAL FL EARLY THIS EVENING, WITH ACTIVITY THEN EXPECTED TO
DISSIPATE BEFORE MIDNIGHT. DEBRIS CLOUDINESS WILL THIN OUT
DURING THE OVERNIGHT AND PREDAWN HOURS, WITH THE ATLANTIC RIDGE
AXIS REMAINING IN PLACE ACROSS NORTH CENTRAL FL. THIS WILL
CREATE LOW LEVEL WEST- SOUTHWESTERLY FLOW THAT COULD ADVECT LOW
STRATUS CLOUD COVER AND FOG NORTHEASTWARD FROM APALACHEE BAY
INTO THE SUWANNEE VALLEY TOWARDS SUNRISE. LOWS WILL FALL TO THE
MID 70S INLAND AND THE UPPER 70S TO AROUND 80 AT COASTAL
LOCATIONS.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/
MAIN HIGHLIGHTS THIS PERIOD:
- DAILY SCATTERED AFTERNOON THUNDERSTORMS.
- INCREASING HEAT INDEX VALUES NEAR HEAT ADVISORY LEVELS EACH
DAY.
LOWER PRECIPITATION CHANCES WILL BE PRESENT TO START OFF THE
WORK WEEK AS MID-LEVEL RIDGING SUPPRESSES CONVECTION. MONDAY,
RAIN/STORM CHANCES WILL BE AT ABOUT 20-40% FOR NORTHEAST FLORIDA
AND THE GEORGIA COAST. ISOLATED TO SCATTERED AFTERNOON AND
EVENING STORMS ARE FORECAST TUESDAY ACROSS MOST OF SOUTHEAST
GEORGIA, AND CLOSER TO THE NORTHEAST FLORIDA COAST. WITH LESS
CLOUD COVER AND STORM COVERAGE, HIGHS WILL BE ABOVE NORMAL,
CLIMBING INTO THE LOWER TO UPPER 90S. MAX AFTERNOON APPARENT
TEMPERATURES WILL RANGE FROM 100- 108 DEGREES, A HEAT ADVISORY
MAY BE NEEDED FOR SOME LOCATIONS EITHER OR BOTH DAYS. CAN'T RULE
OUT SOME EARLY MORNING PATCHY FOG, ESPECIALLY OVER AREAS THAT
RECEIVE A LOT OF RAINFALL.
LONG TERM /WEDNESDAY THROUGH SUNDAY/
MAIN HIGHLIGHTS THIS PERIOD:
- ISOLATED TO SCATTERED AFTERNOON THUNDERSTORM COVERAGE.
- HEAT ADVISORY POTENTIAL EACH DAY.
STORM CHANCES REMAIN LOWER THAN NORMAL THROUGH THE END OF THE
WEEK WITH PRECIPITATION CHANCES GENERALLY MAXING OUT AROUND 40%
EACH AFTERNOON. WEDNESDAY, CONVECTION WILL BE LIMITED TO ALONG
AND NORTH OF I-10 AS WELL AS DOWN THE NORTHEAST FLORIDA COAST.
ISOLATED SHOWERS AND STORMS EXPECTED INLAND THURSDAY, WITH
SLIGHTLY HIGHER CHANCES CLOSER TO THE EAST COAST. PRECIP CHANCES
INCREASE FRIDAY AND SATURDAY AREA-WIDE BUT STILL PEAK IN THE
40-50% RANGE.
WESTERLY SURFACE WINDS WILL ALLOW FOR HOT TEMPERATURES EACH DAY,
EVEN AT THE IMMEDIATE EAST COAST BEACHES AS THE ATLANTIC SEA
BREEZE WILL BE PINNED FROM PUSHING INLAND. MAX AFTERNOON HEAT
INDEX VALUES WILL APPROACH HEAT ADVISORY CRITERIA NEAR THE COAST
AND FOR SOME INLAND LOCATIONS.
AVIATION /18Z SUNDAY THROUGH 18Z MONDAY/
THUNDERSTORMS WILL GRADUALLY MOVE AWAY FROM THE SSI TERMINAL,
WITH ACTIVITY EXPECTED TO MOVE WEST OF THE TERMINAL BY 20Z.
CONVECTION WILL GRADUALLY DEVELOP NEAR THE DUVAL COUNTY
TERMINALS AND SGJ THROUGH THE MID-AFTERNOON HOURS, WITH TEMPO
GROUPS FOR BRIEF SURFACE WIND GUSTS UP TO 25 KNOTS AND IFR
CONDITIONS PLACED IN THE TAFS THROUGH AROUND 20Z AT JAX AND CRG,
WHILE ACTIVITY MAY LINGER THROUGH AROUND 00Z AT VQQ.
THUNDERSTORMS WILL LIKELY DEVELOP NEAR THE SGJ TERMINAL
TOWARDS 19Z, AND A TEMPO GROUP FOR BRIEF SURFACE WIND GUSTS
AROUND 25 KNOTS AND MVFR CONDITIONS PLACED IN THE TAF THROUGH
AROUND 21Z. ACTIVITY SHOULD PROGRESS SOUTHWARD LATER THIS
AFTERNOON AND EVENING, WITH POTENTIAL IMPACTS AT GNV AFTER 21Z.
CONFIDENCE REMAINS TOO LOW FOR A TEMPO GROUP, BUT A PROB30 GROUP
FOR BRIEF SURFACE WIND GUSTS UP TO 25 KNOTS AND MVFR CONDITIONS
DURING HEAVIER DOWNPOURS WAS EXTENDED THROUGH AROUND 01Z.
CONVECTION OVER NORTHEAST AND NORTH CENTRAL FL SHOULD DISSIPATE
BY 03Z, WITH VFR CONDITIONS THEN PREVAILING AT ALL BUT THE VQQ
TERMINAL OVERNIGHT, WHERE PERIODS OF MVFR TO IFR CONDITIONS ARE
EXPECTED AFTER 06Z. VFR CONDITIONS SHOULD THEN PREVAIL BY 12Z.
MARINE
WEAK TROUGHING SITUATED OFF THE SOUTHEASTERN SEABOARD WILL
CONTINUE TO PROGRESS NORTHEASTWARD THIS AFTERNOON, WITH
ATLANTIC HIGH PRESSURE SLOWLY BUILDING WESTWARD ACROSS OUR LOCAL
WATERS TONIGHT AND MONDAY. SCATTERED THUNDERSTORMS WILL DEVELOP
CLOSE TO THE NEAR SHORE WATERS THIS AFTERNOON HOURS. A FEW
STRONGER STORMS WILL BE POSSIBLE, WITH BRIEFLY GUSTY WINDS,
FREQUENT LIGHTNING STRIKES, AND TORRENTIAL DOWNPOURS THROUGH
EARLY THIS EVENING. SOUTHWESTERLY FLOW WILL THEN PREVAIL
BEGINNING ON MONDAY, WITH AN AFTERNOON SEA BREEZE DEVELOPING
OVER THE NEAR SHORE WATERS EACH AFTERNOON, FOLLOWED BY A
SOUTHERLY EVENING WIND SURGE. WINDS AND SEAS ARE FORECAST TO
REMAIN BELOW CAUTION LEVELS THIS WEEK. ONLY ISOLATED AFTERNOON
AND EVENING THUNDERSTORMS ARE FORECAST FROM MONDAY THROUGH
FRIDAY, MAINLY IMPACTING THE NEAR SHORE WATERS.
RIP CURRENTS: BREAKERS OF 2-3 FEET WILL COMBINE WITH AN EASTERLY
OCEAN SWELL AND THE OUTGOING TIDE TO KEEP A HIGH RISK IN PLACE
THIS AFTERNOON AT THE NORTHEAST FL BEACHES. LOWER SURF HEIGHTS
AT THE SOUTHEAST GA BEACHES WILL YIELD A MODERATE RISK. BREAKERS
WILL SUBSIDE ON MONDAY AS PREVAILING WINDS BECOME
SOUTHWESTERLY, BUT THE AFTERNOON SEA BREEZE WILL COMBINE WITH A
LINGERING OCEAN SWELL TO PRODUCE A LOWER END MODERATE RISK AT
AREA BEACHES DURING THE AFTERNOON HOURS. PERSISTENT OFFSHORE
WINDS WILL LIKELY LOWER THIS RISK BY MIDWEEK.
FIRE WEATHER
- PATCHY HIGH AFTERNOON DISPERSIONS BEGINNING TUESDAY.
LIGHT WEST TO SOUTHWEST WINDS WILL KEEP THE ATLANTIC SEABREEZE
NEAR THE COAST EACH DAY, WITH LOWER THUNDERSTORM COVERAGE
EXPECTED MONDAY ONWARD, PRECIPITATION CHANCES WILL BE AROUND
20-40%. TEMPERATURES WILL RISE INTO THE MID TO UPPER 90S INLAND
AND LOW TO MID 90S AT THE COAST BY TUESDAY WITH PEAK HEAT INDEX
VALUES RISING TO HEAT ADVISORY LEVELS 106-110 INTO MIDWEEK.
DISPERSIONS IMPROVE TO THE GOOD RANGE ON MONDAY. PATCHY HIGH
INLAND DISPERSIONS EXPECTED TUESDAY INTO THE END OF NEXT WEEK AS
MIXING HEIGHTS INCREASE UNDER THE RIDGE ALONG WITH INCREASING
WESTERLY TRANSPORT WINDS.
FOG POTENTIAL: SIGNIFICANT FOG DEVELOPMENT IS NOT EXPECTED, WITH
SHALLOW, PATCHY FOG LATE OVERNIGHT LIMITED TO AREAS THAT RECEIVE
LOCALLY HEAVY RAINFALL. A FEW STRONG THUNDERSTORMS MAY PRODUCE
GUSTY OUTFLOWS WITH LOCALLY ERRATIC WINDS.
PRELIMINARY POINT TEMPS/POPS
AMG 75 95 75 95 / 40 20 10 20
SSI 78 92 79 95 / 20 20 0 20
JAX 75 94 75 95 / 30 30 0 20
SGJ 77 91 76 94 / 20 20 0 10
GNV 75 94 74 94 / 30 30 0 10
OCF 75 94 75 94 / 20 10 0 10
JAX WATCHES/WARNINGS/ADVISORIES
FL...HIGH RISK FOR RIP CURRENTS UNTIL 10 PM EDT THIS EVENING FOR FLZ124-
125-138-233-333.
GA...NONE.
MARINE...NONE.
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