921
FXUS62 KJAX 170650
AFDJAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
250 AM EDT FRI JUL 17 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 AFTERNOON & EVENING THUNDERSTORMS
HAZARDS: WIND GUSTS OF 35-45 MPH, FREQUENT LIGHTNING &
LOCALIZED FLOODING
- HEAVY RAINFALL & LOCALIZED FLOODING POSSIBLE ON SUNDAY AND
MONDAY WITH INCREASING THUNDERSTORM COVERAGE, MAINLY NE AND
NORTH CENTRAL FL
- MODERATE RIP CURRENT RISK AT AREA BEACHES THIS AFTERNOON
- HEAT ADVISORY CONDITIONS POSSIBLE TOWARDS THE MIDDLE OF NEXT WEEK
NEAR TERM /THROUGH TONIGHT/
MAIN HIGHLIGHTS TODAY AND TONIGHT:
- SEASONABLY HOT AND HUMID SUMMERTIME WEATHER CONTINUES.
- STRONG PULSE THUNDERSTORMS POSSIBLE LATE THIS AFTERNOON FOR
INLAND NE FL, MAINLY ALONG THE I-75 CORRIDOR; LOCALIZED URBAN
FLOODING POSSIBLE.
FOR TODAY...CONVECTION WILL BE MORE ABUNDANT THIS AFTERNOON,
PARTICULARLY ACROSS NE FL OWING TO THE LIFT AND DESTABILIZATION
OFFERED BY A DEVELOPING UPPER LOW. WITH WEAK STEERING FLOW,
CONVECTIVE EVOLUTION WILL FOLLOW TYPICAL SUMMER TREND WITH THE GULF
AND ATLANTIC SEA BREEZES MOVING INLAND, COLLIDING ALONG THE US 301
CORRIDOR THIS AFTERNOON. BEFORE THE POTENTIAL RELIEF FROM AFTERNOON
STORMS, HIGHS WILL PUSH TOWARD THE MID 90S INLAND AND MAKE IT TO
AROUND 90 AT THE COAST BEFORE THE SEA BREEZE MOVES ONSHORE. PEAK
HEAT INDEX WILL BE SEASONABLY HOT BUT NOT LIKELY TO REACH HEAT
ADVISORY CRITERIA THIS AFTERNOON.
AS MENTIONED ABOVE, A TROPICAL UPPER TROPOSPHERIC TROUGH LIFTING
ACROSS SOUTH FLORIDA THIS MORNING WILL GRADUALLY MOVE NORTHWESTWARD
AND CLOSE OFF INTO AN UPPER LOW OVER THE NORTHEASTERN GULF THIS
AFTERNOON. AS IT DOES SO, A COLD POOL OF AIR IN THE MID LEVELS WILL
BEGIN TO PUSH INTO NORTH CENTRAL FL THIS AFTERNOON HELPING TO
STEEPEN MID LEVEL LAPSE RATES OVER THOSE ZONES. DEEP EASTERLY FLOW
STRENGTHENING AROUND THE NORTHEASTERN PERIPHERY OF THE UPPER LOW
WILL BRING IN SOME DRIER AIR WHICH MAY CAP CONVECTION SOMEWHAT
INITIALLY ALONG THE SEA BREEZE. THE POTENTIAL FOR STRONGER
CONVECTION AND POTENTIAL FOR GUSTY WINDS, DOWNPOURS, AND FREQUENT
LIGHTNING EPISODES WILL GENERALLY FAVOR AREAS WEST OF THE ST JOHNS
RIVER AND SOUTH OF I-10 WHERE THE STEEPER LAPSE RATES AND FORCING
WILL OVERLAP COLLIDING SEA BREEZE AND OUTFLOW BOUNDARIES DURING THE
LATE AFTERNOON AND EARLY EVENING HOURS (5-9 PM).
DUE TO THE HIGH-GRADE - ABOVE THE 90TH PERCENTILE - PRECIPITABLE
WATER (2.25"+), A LOCALIZED HEAVY RAIN AND URBAN FLASH FLOODING IS A
POTENTIAL CONCERN THIS EVENING FOR AREAS ALONG I-75 FROM LAKE CITY
SOUTHWARD. THE LATEST HIRES ENSEMBLE CAMS HAVE IDENTIFIED A MEDIUM
(30-50%) PROBABILITY OF THE AFOREMENTIONED AREAS TO ACCUMULATE 3" OR
MORE RAIN OVER A 3 HOUR PERIOD WHICH IS A MORE "AGGRESSIVE" AMOUNT
BUT WORTH MENTIONING.
OTHERWISE, CONVECTION WILL EXIT TO THE WEST DURING THE LATE EVENING
HOURS WITH SKIES CLEARING BEHIND IT. DUE TO HEAVY RAIN, THERE IS
POTENTIAL FOR SOME PATCHY FOG ALONG THE SUWANNEE RIVER VALLEY DURING
THE EARLY HOURS SATURDAY.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/
MAIN HIGHLIGHTS:
- HEAVY RAIN AND LOCALIZED FLOOD CONCERNS
- DAILY BOUTS OF SHOWERS AND STORMS
A TROPICAL UPPER TROPOSPHERIC TROUGH (TUTT) WILL BE LOCATED ALONG
THE WEST FL COAST SATURDAY WITH AN EMBEDDED UPPER LOW LOCATED NEAR
TAMPA. THIS UPPER LOW PRESSURE CENTER WILL SLOWLY MIGRATE NORTH-
NORTHEAST THROUGH SUNDAY, BUT BECOME MORE ILL-DEFINED INTO EARLY
NEXT WEEK. MODEL GUIDANCE ALSO SHOWS QUASI-STATIONARY SURFACE
TROUGHING EXTENDING FROM THE CENTRAL CAROLINAS TO THE FL PANHANDLE
INTO THE EASTERN GULF. A WEAK SURFACE LOW MAY ATTEMPT TO DEVELOP
BENEATH THE UPPER FEATURE AND ACQUIRE SOME SUBTROPICAL OR TROPICAL
CHARACTERISTICS AS IT MOVES NORTHEAST ON SUNDAY. HOWEVER, CONFIDENCE
IN SURFACE LOW DEVELOPMENT REMAINS LOW, WITH THE NATIONAL HURRICANE
CENTER MAINTAINING A 20 PERCENT CHANCE OF TROPICAL DEVELOPMENT.
THE COMBINATION OF THE RICH MOISTURE WITH PWATS AROUND 2 INCHES
AND TEMPERATURES COOLING ALOFT WILL INCREASE AFTERNOON AND EVENING
THUNDERSTORM COVERAGE. DEEP LAYER FLOW IS SOUTHERLY BOTH DAYS ABOUT
10 MPH, PERHAPS A LITTLE STRONGER ON SUNDAY.
REGARDLESS OF TROPICAL DEVELOPMENT, THE DEEP TROPICAL AIRMASS WILL
OVERSPREAD THE REGION THROUGH THE WEEKEND, SUPPORTING NUMEROUS
SHOWERS AND THUNDERSTORMS EACH AFTERNOON AND EVENING. BEST
CONVECTIVE COVERAGE AND HEAVY RAINFALL AMOUNTS LOOK TO OCCUR OVER
INLAND AREAS GENERALLY SOUTH OF WAYCROSS FOR BOTH DAYS, AS THE EAST
COAST SEA BREEZE SHOULD PUSH INLAND FAR ENOUGH TO KEEP THE BULK OF
THE HEAVIER STORMS FURTHER WEST. THE PRIMARY HAZARD WITH STORMS WILL
BE PERIODS OF HEAVY RAINFALL CAPABLE OF PRODUCING LOCALIZED
FLOODING, ESPECIALLY ACROSS NORTHEAST AND NORTH CENTRAL FLORIDA
WHERE REPEATED ROUNDS OF CONVECTION ARE MOST LIKELY. FREQUENT
LIGHTNING AND LOCALLY GUSTY WINDS WILL ACCOMPANY THE STRONGER STORMS.
TEMPERATURES WILL REMAIN SEASONABLY HOT SATURDAY, WITH HIGHS IN THE
LOWER TO MIDDLE 90S AND PEAK HEAT INDEX VALUES OF 102 TO 107
DEGREES. INCREASING CLOUD COVER AND NUMEROUS SHOWERS AND STORMS ON
SUNDAY SHOULD HOLD HIGHS CLOSER TO THE UPPER 80S TO LOWER 90S WHILE
MAINTAINING HUMID CONDITIONS.
LONG TERM /MONDAY THROUGH THURSDAY/
MAIN HIGHLIGHTS FOR NEXT WEEK:
- SCATTERED TO NUMEROUS AFTERNOON THUNDERSTORMS
- POTENTIAL HEAT ADVISORY CONDITIONS BY THE MIDDLE OF NEXT WEEK
WEAK MID TO UPPER LEVEL TROUGH WILL CONTINUE ACROSS THE REGION EARLY
NEXT WEEK, ORIENTED FROM THE EASTERN GULF THEN NORTHEASTWARD OVER
OUR FORECAST AREA TO THE CAROLINA COAST. THIS UPPER TROUGH LOOKS TO
WEAKEN AND BECOME LESS DEFINED BY MID WEEK. LOW LEVEL TROUGHING ALSO
CONTINUES OVER THE SOUTHEAST STATES INTO THE NORTHEAST GULF EARLY
NEXT WEEK. IMPORTANTLY, THE NORTHEAST GULF CONTINUES TO BE AN AREA
THAT IS BEING MONITORED BY THE NHC EARLY NEXT WEEK WITH LOW CHANCES
OF TROPICAL DEVELOPMENT. STILL MUCH UNCERTAINTY IF ANYTHING DEVELOPS
GIVEN IT WOULD BE CLOSE TO LAND AND MODELS ARE HAVING A HARD TIME
SHOWING ANYTHING WELL-DEFINED. AS LOW TO MID LEVEL RIDGING BEGINS TO
BUILD BACK IN OVER THE FL PENINSULA BY WEDNESDAY, ANY TROUGHING OR
LOW PRESSURE WOULD SHIFT NORTHWARD. STILL LOOKS LIKE NUMEROUS
SHOWERS AND STORMS FOR MONDAY AND TUESDAY, ESPECIALLY OVER NORTHEAST
AND NORTH CENTRAL FL. THE HIGH PWAT AIR OF NEAR 2 TO 2.2 INCHES
(NEAR OR ABOVE THE 90TH CLIMATE PERCENTILE), COUPLED WITH CONVERGENT
SOUTH OR SOUTHWEST LOW LEVEL FLOW WILL SUPPORT A LOCALIZED FLOODING
RAIN THREAT FOR INLAND AREAS, ESPECIALLY NORTHEAST AND NORTH CENTRAL
FL.
COVERAGE OF CONVECTION APPEARS TO DECREASE SLIGHTLY WEDNESDAY AND
THURSDAY. AT THE SAME TIME, INCREASING HEIGHTS ALOFT WILL ALLOW
TEMPERATURES TO CLIMB BACK INTO THE MIDDLE 90S, WITH OPPRESSIVE
HUMIDITY PUSHING PEAK HEAT INDEX VALUES TO ABOUT THE 105 TO 110
DEGREE RANGE BY MIDWEEK. GIVEN THIS, HEAT ADVISORY CONDITIONS MAY
BECOME INCREASINGLY LIKELY FOR SOME AREAS.
AVIATION /06Z FRIDAY THROUGH 06Z SATURDAY/
VFR CONDITIONS THROUGH 17Z, THOUGH A ONE TO TWO HOUR PERIOD OF LOW-
BASED CUMULUS (AROUND 2KFT) WILL BE POSSIBLE AROUND 15Z. SEA BREEZE
ACTIVITY WILL PUSH INLAND FASTER THIS AFTERNOON, LIMITING THE
POTENTIAL FOR CONVECTIVE IMPACTS AT KSSI, KSGJ, AND KCRG AS WELL.
MAIN AREAS AND TERMINALS IMPACTED BY TSRA WILL BE WEST OF I-95 WITH
INCREASING CHANCES THE FARTHER WEST YOU GO. HEAVY RAIN WITH
THUNDERSTORMS WILL RESTRICT TERMINAL VISIBILITY TO IFR OR LESS
TEMPORARILY. THE CONCENTRATION OF CONVECTION WILL BE ALONG THE GULF
AND ATLANTIC SEA BREEZE MERGER, WHICH WILL BE NEAR KGNV AROUND 20-
22Z. EXPECT ATLANTIC SEA BREEZE TO ARRIVE AROUND 16Z AT COASTAL
TERMINALS THEN KJAX/KVQQ AROUND 18Z/19Z.
MARINE
LIGHT FLOW WILL FAVOR A DOMINANT SEA BREEZE WIND PATTERN THIS
AFTERNOON. THIS WEEKEND SOUTHERLY WINDS WILL STRENGTHENING TO
EXERCISE CAUTION LEVELS AS GRADIENTS INCREASE BETWEEN A TROUGH OVER
THE SOUTHEASTERN US AND STRENGTHEN BERMUDA HIGH PRESSURE. AS
STEERING FLOW PATTERN TURNS OFFSHORE THIS WEEKEND, CHANCES FOR
AFTERNOON THUNDERSTORMS WILL INCREASE.
SURFACE TROUGHING WILL STRENGTHEN SUNDAY AND MONDAY, WITH WEAK LOW
PRESSURE POSSIBLY DEVELOPING OVER THE NORTHEAST GULF. THE NATIONAL
HURRICANE CENTER HAS MAINTAINED A LOW CHANCE, OR 20 PERCENT, OF WEAK
TROPICAL DISTURBANCE DEVELOPMENT. THE WEAK WAVE OF LOW PRESSURE
SHOULD PROGRESS NORTHEASTWARD ACROSS OUR LOCAL WATERS EARLY NEXT
WEEK.
RIP CURRENTS:
SEA BREEZE WINDS THIS AFTERNOON WILL LEAD TO A LOW-END MODERATE RISK
OF RIP CURRENTS THIS AFTERNOON. SOUTHERLY WIND SURGES DURING THE
EVENING HOURS THIS WEEKEND MAY BUILD SURF HEIGHTS TO 2-3 FEET AT THE
NORTHEAST FL BEACHES AND TO AROUND 2 FEET AT THE SOUTHEAST GA
BEACHES, YIELDING A MODERATE RISK AT ALL AREA BEACHES.
FIRE WEATHER
SURFACE AND TRANSPORT WIND SPEEDS ARE FORECAST TO BE WEAK TODAY
WHICH WILL LEAD TO POOR TO FAIR DISPERSION VALUES. SLIGHTLY HIGHER
SURFACE AND TRANSPORT WIND SPEEDS ON SATURDAY WILL IMPROVE
DISPERSION TO THE FAIR TO GENERALLY GOOD RANGE. MOISTURE STEADILY
INCREASES ACROSS REGION, WITH RAIN AND STORM CHANCES INCREASING
THROUGH THE WEEKEND. ANY STORMS THAT MANAGE TO DEVELOP WILL BE
CAPABLE OF PRODUCING FREQUENT LIGHTNING STRIKES, HIGH WIND GUSTS,
AND HEAVY DOWNPOURS.
FOG POTENTIAL AND OTHER REMARKS: SIGNIFICANT FOG DEVELOPMENT IS NOT
EXPECTED FOR THE NEXT SEVERAL NIGHTS. GUSTY AND ERRATIC WINDS WILL
BE POSSIBLE IN AND NEAR THUNDERSTORMS, WITH OCCASIONAL OUTFLOW
BOUNDARIES CAPABLE OF PRODUCING SUDDEN WIND SHIFTS WELL AWAY FROM
ONGOING CONVECTION.
PRELIMINARY POINT TEMPS/POPS
AMG 95 75 94 74 / 30 30 60 50
SSI 92 80 93 78 / 10 10 30 20
JAX 94 76 94 75 / 40 20 50 20
SGJ 91 76 93 75 / 30 10 40 20
GNV 94 73 93 73 / 60 40 60 20
OCF 92 73 92 74 / 80 30 70 30
JAX WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GA...NONE.
MARINE...NONE.
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