543
FXUS62 KJAX 181828
AFDJAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
228 PM EDT FRI SEP 18 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
- ISOLATED THUNDERSTORMS THIS AFTERNOON FOR NORTH CENTRAL FL.
- INCREASING THUNDERSTORM COVERAGE THIS WEEKEND AND INTO NEXT
WITH ISOLATED STRONG THUNDERSTORMS POSSIBLE.
- MODERATE RIP CURRENT RISK AT ALL AREA BEACHES
NEAR TERM /THROUGH TONIGHT/
MAIN HIGHLIGHTS THROUGH TONIGHT:
- MODERATE RIP CURRENT RISK AT ALL AREA BEACHES
- ISOLATED STORMS THIS AFTERNOON FOR NORTH CENTRAL FL
SUFFICIENT MOISTURE AND COLD TEMPS ALOFT OWING TO A BROAD UPPER
TROPOSPHERIC TROUGH SITUATED OFF THE EASTERN FL COAST WILL LEAD TO
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS NORTH CENTRAL FL
THIS AFTERNOON. CONVERSELY, SUBSIDENT AND DRIER AIR ACROSS INLAND
SOUTHEAST GA AND THE SUWANNEE VALLEY WILL LIMIT SHOWER OR CONVECTIVE
DEVELOPMENT. FOR THUNDERSTORM OCCURRENCE TODAY, THE ZONE THAT WILL
BE AT HIGHEST RISK WILL BE PRIMARILY ALONG AND SOUTH OF LINE FROM
GAINESVILLE TO JACKSONVILLE.
BENEATH THE POOL OF COLD AIR ALOFT, DIURNAL HEATING SHOULD PROMOTE
MODEST TO STRONG DESTABILIZATION (MUCAPE 2,500-3,000 J/KG) AND SPAWN
WIDELY SCATTERED SHOWERS AND A FEW ISOLATED THUNDERSTORMS (~20%)
THROUGH THE AFTERNOON. THOUGH THERMODYNAMICS WILL BE FAVORABLE,
THERE WILL BE A "TUG OF WAR" BETWEEN BUOYANT UPDRAFTS AND BROADER
SUBSIDENT AIR BENEATH CONVERGENT NORTHEASTERLY FLOW ALOFT,
ACTIVELY SUPPRESSING ASCENT. IF A STRONG ENOUGH UPDRAFT CAN
OVERCOME AND REALIZE AVAILABLE ENERGY, THE PRIMARY THREAT WILL
BE LIGHTNING FOLLOWED BY A SECONDARY THREAT OF GUSTY OUTFLOW
WINDS.
OUTSIDE OF THE LIMITED CONVECTIVE POTENTIAL TODAY, A BREEZY ONSHORE
FLOW WILL KEEP THE COASTAL AREAS COOLER WITH HIGHS IN THE UPPER 80S
WHILE INLAND HIGHS PUSH INTO THE LOW 90S AMID A DRIER AIRMASS AND
DEWPOINTS IN THE MID 60S.
FOR TONIGHT, THE AFOREMENTIONED UPPER TROUGH WILL RETROGRADE ACROSS
THE FLORIDA PENINSULA. AS IT DOES, SURFACE ONSHORE FLOW WILL WEAKEN
DECREASING COASTAL CONVERGENCE AND POTENTIAL FOR NOCTURNAL COAST
SHOWERS. PARTLY CLEAR SKIES WILL LET TEMPERATURES FALL TO THE LOW
70S INLAND WHILE THE WARMING ONSHORE FLOW LIMITS COOLING NEAR THE
COAST TO THE MID AND UPPER 70S.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/
MAIN HIGHLIGHTS THIS PERIOD: (SATURDAY THROUGH SUNDAY NIGHT)
- SCATTERED TO POSSIBLY NUMEROUS SHOWERS AND STORMS THIS WEEKEND,
WITH THE GREATEST CHANCES SUNDAY
SURFACE HIGH PRESSURE WILL BE CENTERED TO THE NORTHEAST SATURDAY AND
SATURDAY NIGHT. THE HIGH WILL WEAKEN SUNDAY INTO SUNDAY NIGHT, AS A
TROUGH DEVELOPS TO THE NORTHWEST. AN UPPER LOW CENTERED OVER THE
EASTERN GULF WILL PROVIDE ADDED INSTABILITY THIS PERIOD.
PRECIPITATION CHANCES WILL BE LIMITED SOMEWHAT BY THE SURFACE
RIDGING SATURDAY. WITH THE INFLUENCE OF THE HIGH DISSIPATING SUNDAY,
AND UPPER TROUGH IN PLACE PRECIPITATION CHANCES WILL BE MUCH HIGHER.
TEMPERATURES WILL TREND ABOVE AVERAGE THIS PERIOD.
LONG TERM /MONDAY THROUGH THURSDAY/
MAIN HIGHLIGHTS THIS PERIOD: (MONDAY THROUGH FRIDAY)
- DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS WITH LOCALLY HEAVY
RAINFALL POSSIBLE
AN INVERTED SURFACE TROUGH WILL MOVE ACROSS THE AREA THROUGH TUESDAY
NIGHT. THIS TROUGH WILL MOVE OFFSHORE WEDNESDAY, THEN MOVE TO THE
NORTHEAST OF THE AREA THROUGH THURSDAY, AS A HIGH PRESSURE RIDGE
BUILDS DOWN THE EAST COAST. HIGH PRESSURE WILL BUILD TO THE
NORTHWEST THURSDAY NIGHT THROUGH FRIDAY.
ABOVE AVERAGE PRECIPITATION CHANCES ARE FORECAST THROUGH WEDNESDAY,
THEN CLOSER TO AVERAGE THURSDAY AND FRIDAY.
TEMPERATURES THIS PERIOD BE NEAR TO A LITTLE AVERAGE THROUGH
WEDNESDAY, THEN NEAR TO A LITTLE BELOW THURSDAY AND FRIDAY.
AVIATION /18Z FRIDAY THROUGH 18Z SATURDAY/
SPOTTY SHOWERS CONTINUE TO TRACK SOUTHWESTWARD OVER NE FL, YIELDING
VCSH THROUGH THE AFTERNOON. THERE'S A VERY LIMITED CHANCE (<15%) OF
THUNDERSTORM DEVELOPMENT AT KGNV BUT CONFIDENCE IS TO LOW TO MENTION
AT THIS TIME. OTHERWISE, PREDOMINANT CONDITIONS WILL BE VFR WITH
MULTILAYERED CLOUDS AND LOWEST BASES AROUND 3-4KFT. NORTHEASTERLY
WINDS PREVAIL AT ALL SITES, AROUND 10-15 KNOTS, AND WILL BEGIN TO
DECREASE AFTER 22Z. VFR CONDITIONS PERSIST TONIGHT BUT COASTAL
AIRFIELDS MAY EXPERIENCE BRIEF MVFR CEILINGS AS BOUTS OF
STRATOCUMULUS PUSH IN FROM THE ATLANTIC. FOR INLAND SITES, LIGHT FOG
MAY DEVELOP BRIEFLY DURING THE EARLY MORNING HOURS SATURDAY AS WINDS
TREND CALM. INCREASING CHANCE FOR TSRA AND SHRA AT TERMINALS
SATURDAY, PARTICULARLY ALONG THE I-75 CORRIDOR, WITH ENE TO E WINDS
AROUND 5-12 KNOTS.
MARINE
A WEAK TROUGH POSITIONED OVER THE EAST COAST OF FLORIDA WILL
CONTINUE THE POTENTIAL FOR SCATTERED SHOWERS AND POSSIBLY AN
EMBEDDED THUNDERSTORM THROUGH LATE THIS AFTERNOON, MOSTLY FOR THE
WATERS FROM ST. AUGUSTINE SOUTHWARD. WINDS AND SEAS SHOULD REMAIN
BELOW CAUTION LEVELS DURING THE NEXT SEVERAL DAYS THROUGHOUT OUR
LOCAL WATERS. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO INCREASE
BEGINNING LATE SATURDAY NIGHT, WITH ACTIVITY LIKELY CONTINUING
THROUGH AT LEAST EARLY NEXT WEEK. A STRONGER HIGH PRESSURE CENTER
MAY BUILD SOUTHWARD LATER NEXT WEEK, POTENTIALLY RESULTING IN
ANOTHER ROUND OF NORTHEASTERLY WINDS ACROSS OUR LOCAL WATERS.
RIP CURRENTS: BREEZY ONSHORE WINDS WILL KEEP BREAKERS IN THE 3-4
FOOT RANGE AT THE NORTHEAST FL BEACHES TODAY, WHILE VALUES SUBSIDE
TO THE 2-3 FOOT RANGE AT THE SOUTHEAST GA BEACHES. THESE CONDITIONS
WILL GENERALLY YIELD A HIGHER END MODERATE RISK AT ALL AREA BEACHES.
NORTHEASTERLY WINDS WILL ONLY GRADUALLY SUBSIDE THIS WEEKEND AND
EARLY NEXT WEEK, MAINTAINING A MODERATE RISK AT AREA BEACHES.
FIRE WEATHER
HIGH PRESSURE WILL BE NORTHEAST OF THE REGION THROUGH THE WEEKEND.
AN INVERTED THROUGH WILL BE OVER THE AREA EARLY IN THE WEEK. THUS
TROUGH WILL MOVE TO THE NORTHEAST DURING THE MIDDLE OF NEXT WEEK, AS
A HIGH PRESSURE RIDGE BUILDS DOWN THE EAST COAST OF THE US.
FOG POTENTIAL...NO SIGNIFICANT FOG EXPECTED. HOWEVER, PATCHY FOG IS
POSSIBLE FOR INLAND AREAS IN THE EARLY MORNING HOURS THIS WEEKEND.
PRELIMINARY POINT TEMPS/POPS
AMG 93 70 92 71 / 10 10 30 20
SSI 88 75 88 76 / 0 10 10 20
JAX 89 70 90 73 / 10 10 10 10
SGJ 87 76 88 75 / 20 10 20 30
GNV 91 70 91 71 / 20 0 30 0
OCF 92 70 91 70 / 20 0 30 0
JAX WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GA...NONE.
MARINE...NONE.
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