358
FXUS62 KJAX 122315
AFDJAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
715 PM EDT WED AUG 12 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
- OPPRESSIVE HEAT & HUMIDITY CONTINUES AREA-WIDE. HEAT
ADVISORIES IN EFFECT THURSDAY. EXTREME HEAT WARNING FOR
COASTAL SOUTHEAST GA THURSDAY AFTERNOON. DAILY HEAT ADVISORIES
LIKELY CONTINUE FOR MUCH OF OUR AREA INTO NEXT WEEK
- DAILY SCATTERED AFTERNOON & EVENING TSTORMS THURS THROUGH TUES
UPDATE
STRONG/SEVERE THUNDERSTORMS HAVE ENDED FOR OUR AREA THIS
EVENING. STRATIFORM RAIN WITH SOME RUMBLES OF THUNDER WILL
LINGER OVER THE AREA FOR THE NEXT COUPLE OF HOURS BEFORE
DISSIPATING.
NEAR TERM /UNTIL 7 AM THURSDAY MORNING/
MAIN HIGHLIGHTS:
- STRONG TO ISOLATED SEVERE THUNDERSTORMS THIS AFTERNOON THROUGH
EARLY EVENING. STRONGER STORMS WILL BE CAPABLE OF PRODUCING DAMAGING
WIND GUSTS, FREQUENT LIGHTNING STRIKES, AND TORRENTIAL DOWNPOURS.
- LOCALIZED FLOOD THREAT THROUGH EARLY THIS EVENING AS
WAVES OF DOWNPOURS IMPACT PORTIONS OF OUR AREA.
- HEAT ADVISORIES REMAIN POSTED THROUGH 7 PM THIS EVENING FOR MOST
OF OUR AREA.
AFTERNOON SURFACE ANALYSIS DEPICTS HIGH PRESSURE (1019 MILLIBARS)
CENTERED OVER THE NORTHEAST GULF. ALOFT...DEEP-LAYERED RIDING
EXTENDING FROM TEXAS SOUTHEASTWARD THROUGH THE NORTHEASTERN GULF WAS
PRODUCING DEEP AND UNSTABLE NORTHWESTERLY FLOW ACROSS OUR REGION,
WITH A SHORTWAVE TROUGH EMBEDDED WITHIN THIS FLOW EXITING THE
GEORGIA COAST NEAR THE SAVANNAH RIVER ENTRANCE. LATEST GOES-EAST
DERIVED TOTAL PRECIPITABLE WATER IMAGERY INDICATES THAT TROPICAL
MOISTURE REMAINS IN PLACE FOR LOCATIONS ALONG AND NORTH OF THE
INTERSTATE 10 CORRIDOR, WHERE PWATS RANGED FROM 2 - 2.25 INCHES. A
SLIGHTLY DRIER AIR MASS EXISTS TO THE SOUTH OF THE I-10 CORRIDOR,
WHERE PWATS WERE MOSTLY IN THE 1.7 - 1.9 INCH RANGE. A CONVERGENT
ZONE ASSOCIATED WITH THE AFOREMENTIONED SHORTWAVE TROUGH WAS FIRING
NUMEROUS THUNDERSTORMS ACROSS SOUTHEAST GA AND NORTHEAST FL, MAINLY
FOR LOCATIONS FROM WAYCROSS SOUTHEASTWARD TO THE I-10 CORRIDOR.
ACTIVITY WAS PROGRESSING BRISKLY SOUTHEASTWARD AT 20-30 MPH. OUTSIDE
OF RAIN-COOLED LOCATIONS, OPPRESSIVE HEAT AND HUMIDITY CONTINUES,
WITH TEMPERATURES AT 18Z GENERALLY IN THE LOW AND MID 90S, WITH
DEWPOINTS IN THE 70S DRIVING HEAT INDEX VALUES UP TOWARDS 105
DEGREES.
OUTFLOW BOUNDARIES EMANATING FROM THE CONVECTIVE ZONE SHOULD ALLOW
FOR THUNDERSTORMS TO GRADUALLY SHIFT SOUTHWARD AS THE AFTERNOON
PROGRESSES, WITH INDIVIDUAL STORM CELLS CONTINUING TO PROGRESS
QUICKLY SOUTHEASTWARD. STRONG TO ISOLATED SEVERE THUNDERSTORMS WILL
REMAIN POSSIBLE THROUGH THE EARLY EVENING HOURS AS THE FOCUS FOR
ACTIVITY SHIFTS SOUTH OF THE I-10 CORRIDOR. PLENTY OF INSTABILITY
AND DEEP TROPICAL MOISTURE WILL KEEP THE POTENTIAL FOR WET
MICROBURSTS IN PLACE, WITH STORMS ALSO PULSING AS OUTFLOW BOUNDARIES
COLLIDE. STRONGER CONVECTION WILL BE CAPABLE OF PRODUCING DOWNBURST
WIND GUSTS OF 40-60 MPH, ALONG WITH FREQUENT LIGHTNING STRIKES. DEEP
NORTHWESTERLY FLOW WILL PRESENT A RISK FOR TRAINING CONVECTION, AND
STORMS MOVING SOUTHEASTWARD REPEATEDLY OVER THE SAME LOCATIONS WILL
INCREASE THE THREAT FOR LOCALIZED FLOODING, ESPECIALLY FOR URBAN OR
NORMALLY FLOOD PRONE LOCATIONS. OUTFLOW BOUNDARIES SHOULD ALSO
DEVELOP CONVECTION THIS AFTERNOON ACROSS COASTAL SOUTHEAST GA, WHERE
A FEW STRONGER STORMS WILL BE POSSIBLE AS ACTIVITY POTENTIALLY
INTERACTS WITH A PINNED ATLANTIC SEA BREEZE BOUNDARY AT THE
IMMEDIATE COAST.
CONVECTION SHOULD DISSIPATE OVER NORTH CENTRAL FL AND THE I-75
CORRIDOR BY THE MID-EVENING HOURS AS SHORTWAVE ENERGY MOVES FURTHER
OFFSHORE OF THE GEORGIA COAST. DEBRIS CLOUD COVER WILL THIN OUT
OVERNIGHT, WITH VIEWING OF THE ANNUAL PERSEID METEOR SHOWER
IMPROVING DURING THE PREDAWN HOURS ACROSS OUR AREA FROM NORTH TO
SOUTH. OTHERWISE, A WARM AND HUMID AIR MASS WILL KEEP LOWS MOSTLY IN
THE MID TO UPPER 70S.
SHORT TERM /7 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/
MAIN HIGHLIGHTS THIS PERIOD:
- DAILY ISOLATED TO SCATTERED AFTERNOON THUNDERSTORMS, SOME OF WHICH
COULD BE STRONG
- HEAT INDEX VALUES NEAR HEAT ADVISORY LEVELS EACH DAY. EXTREME HEAT
WATCH IN PLACE ALONG COASTAL SE GA THURSDAY
A HIGH PRESSURE RIDGE WILL EXTEND ACROSS SOUTHERN FL THIS PERIOD,
WITH A TROUGH TO THE NORTH. THE RIDGE WILL WEAKEN INTO FRIDAY.
THE FLOW ON THURSDAY WILL PREVAIL FROM THE WEST, WHICH WILL KEEP THE
EAST COAST SEA BREEZE FROM GETTING MUCH FURTHER INLAND THAN THE
BEACHES. THIS WILL HELP THE HEAT TO PUSH ALL THE WAY TO THE BEACHES.
THE COMBINATION OF HEAT AND HUMIDITY WILL RESULT IN HEAT ADVISORY
LEVEL CONDITIONS ACROSS MUCH OF THE AREA, BUT HEAT WARNING LEVELS
EXPECTED FOR COASTAL SE GA. CONVECTION ON THURSDAY WILL LARGELY BE
DRIVEN BY DIURNAL HEATING.
WITH THE WEAKER HIGH, THE FLOW FROM THE WEST WILL NOT BE AS STRONG,
ALLOWING THE EAST COAST SEA BREEZE TO PUSH FURTHER INLAND.
CONVECTION ON FRIDAY WILL BE DRIVEN BY DIURNAL INSTABILITY, AND
ENHANCED BY SEA BREEZE INTERACTIONS. TEMPERATURES WILL BE SIMILAR
FRIDAY AS THURSDAY, BUT A FEW DEGREES COOLER AT THE BEACHES DUE TO
THE SEA BREEZE. HEAT ADVISORY LEVEL CONDITIONS ARE ANTICIPATED
FOR MUCH OF THE AREA.
LONG TERM /SATURDAY THROUGH WEDNESDAY/
MAIN HIGHLIGHTS THIS PERIOD:
- WARM TEMPERATURES CONTINUE OVER THE WEEKEND, WITH HEAT ADVISORIES
LIKELY ON SATURDAY
- ISOLATED TO SCATTERED THUNDERSTORMS EACH AFTERNOON EVENING, WHICH
COULD BECOME STRONG
A COLD FRONT WILL MOVE SOUTH INTO THE AREA SATURDAY, THEN STALL NEAR
THE FL/GA LINE THROUGH SUNDAY, BEFORE WEAKENING OVER THE AREA EARLY
NEXT WEEK. ANOTHER FRONT WILL APPROACH FROM THE NORTH DURING THE
MIDDLE OF NEXT WEEK.
AFTERNOON AND EVENING CONVECTION WILL BE ISOLATED TO SCATTERED THIS
PERIOD. THE HIGHEST CHANCE THIS PERIOD WILL BE ON SUNDAY, DUE TO THE
FRONT BEING OVER THE AREA.
ABOVE AVERAGE TEMPERATURES ARE EXPECTED THROUGHOUT THIS PERIOD.
AVIATION /00Z THURSDAY THROUGH 00Z FRIDAY/
LIGHT RAIN WILL LINGER NEAR THE DUVAL TAF SITES AND SGJ THROUGH
AROUND 03Z. SHOWERS AND STORMS CURRENTLY IN THE VICINITY OF GNV MAY
MOVE OVERHEAD BUT WILL LIKELY REMAIN AS LIGHT RAIN. VARIABLE WINDS 5-
10 KTS THIS EVENING BECOME WESTERLY LESS THAN 5 KTS OVERNIGHT. WEST-
NORTHWEST WINDS 5-10 KTS DEVELOP AFTER 15Z. WINDS SHIFT TO SOUTHERLY
AFTER 18Z FOR THE COASTAL SITES AS THE ATLANTIC SEA BREEZE SHIFTS
INLAND. ANOTHER ROUND OF POTENTIALLY STRONG CONVECTION WILL LIKELY
IMPACT OUR REGION ON THURSDAY AFTERNOON.
MARINE
HIGH PRESSURE POSITIONED OVER THE EASTERN GULF WILL WEAKEN ON
THURSDAY AS TROUGHING DEVELOPS OVER THE SOUTHEASTERN STATES.
WESTERLY WINDS WILL PREVAIL DURING THE NEXT SEVERAL DAYS, WITH THE
SEA BREEZE SHIFTING WINDS TO SOUTHEASTERLY OR SOUTHERLY OVER THE
NEAR SHORE WATERS EACH AFTERNOON, FOLLOWED BY SOUTHERLY EVENING WIND
SURGES THAT MAY BRIEFLY INCREASE SPEEDS TO NEAR CAUTION LEVELS
BEFORE SUBSIDING AFTER MIDNIGHT. STRONG TO ISOLATED SEVERE
THUNDERSTORMS MAY IMPACT PORTIONS OF OUR LOCAL WATERS THIS AFTERNOON
THROUGH EARLY THIS EVENING, WITH STRONGER STORMS CAPABLE OF
PRODUCING DAMAGING WIND GUSTS, FREQUENT LIGHTNING STRIKES, AND
LOCALLY ROUGH SEAS. SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS WILL REMAIN POSSIBLE EACH DAY THROUGH THE UPCOMING
WEEKEND.
RIP CURRENTS: PREVAILING OFFSHORE WINDS DURING THE OVERNIGHT AND
MORNING HOURS WILL KEEP SURF HEIGHTS BELOW 2 FEET AT AREA BEACHES
OUTSIDE OF THUNDERSTORM ACTIVITY, MAINTAINING A MOSTLY LOW RISK
DURING THE NEXT SEVERAL DAYS.
FIRE WEATHER
- HEAT HEADLINES IN EFFECT
HIGH PRESSURE RIDGE WILL BE LOCATED ACROSS SOUTHERN FL WITH A TROUGH
TO THE NORTH THROUGH FRIDAY. A FRONT WILL MOVE SOUTH INTO THE AREA
SATURDAY, BEFORE STALLING NEAR THE FL/GA LINE SUNDAY. THE BOUNDARY
WILL DISSIPATE EARLY NEXT WEEK. ANOTHER FRONT WILL APPROACH TOWARD
THE MIDDLE OF NEXT WEEK. ISOLATED TO SCATTERED THUNDERSTORMS EACH
AFTERNOON AND EVENING. TEMPERATURES WILL BE ABOVE AVERAGE THIS
PERIOD, WITH HEAT INDICES NEAR OR ABOVE ADVISORY LEVELS EACH DAY.
FOG POTENTIAL: SIGNIFICANT FOG DEVELOPMENT IS NOT EXPECTED, WITH
SHALLOW, PATCHY FOG LATE OVERNIGHT LIMITED TO AREAS THAT RECEIVE
LOCALLY HEAVY RAINFALL.
CLIMATE
DAILY RECORD HIGH TEMPERATURES ARE POSSIBLE BY THU-FRI:
THURSDAY, AUGUST 13TH:
KJAX: 99/2023
KGNV: 99/2023
KAMG: 100/9999
KCRG: 96/2023
FRIDAY AUGUST 14TH:
KJAX: 99/2023
KGNV: 97/2023
KAMG: 101/2023
KCRG: 98/2023
SATURDAY AUGUST 15TH:
KJAX: 99/1956
KGNV: 100/1918
KAMG: 99/1995
KCRG: 97/9999
PRELIMINARY POINT TEMPS/POPS
AMG 76 96 77 96 / 10 30 10 30
SSI 79 96 79 95 / 20 30 10 20
JAX 76 95 76 95 / 30 40 10 40
SGJ 78 94 77 94 / 40 40 10 30
GNV 77 95 75 95 / 80 50 30 60
OCF 76 95 75 96 / 70 50 20 40
JAX WATCHES/WARNINGS/ADVISORIES
FL...HEAT ADVISORY FROM 11 AM TO 8 PM EDT THURSDAY FOR FLZ021-023-
024-030-031-035-038-120-124-125-132-136>138-140-220-225-
232-233-236-237-240-322-325-333-340-422-425-433-522-533-
633.
GA...HEAT ADVISORY FROM 11 AM TO 8 PM EDT THURSDAY FOR GAZ132>136-
149-151-152-162-163-250-264-350-364.
EXTREME HEAT WARNING FROM 11 AM TO 8 PM EDT THURSDAY FOR
GAZ153-154-165-166.
MARINE...NONE.
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