947
FXUS62 KJAX 121223
AFDJAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
823 AM 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 AND HUMIDITY CONTINUES THROUGH THE WEEKEND.
HEAT ADVISORY FOR ALL OF NORTH CENTRAL AND NORTHEAST FL AND
COASTAL SOUTHEAST GA TODAY. EXTREME HEAT WATCH FOR COASTAL
SOUTHEAST GA ON THURSDAY. HEAT ADVISORIES LIKELY ELSEWHERE
EACH DAY THROUGH THE EARLY EVENING HOURS.
- SCATTERED TO NUMEROUS AFTERNOON AND EVENING THUNDERSTORMS
TODAY AND THURSDAY. STRONG TO ISOLATED SEVERE STORMS ARE
POSSIBLE, WITH WIND GUSTS OF 40-60 MPH, FREQUENT LIGHTNING
STRIKES, AND HEAVY DOWNPOURS.
- SCATTERED AFTERNOON AND EVENING THUNDERSTORMS FROM FRIDAY
THROUGH MONDAY.
NEAR TERM /THROUGH TONIGHT/
MAIN HIGHLIGHTS:
- HEAT ADVISORY IN EFFECT FROM NOON THROUGH 7 PM TODAY FOR ALL
OF NORTH CENTRAL AND NORTHEAST FL AND COASTAL SOUTHEAST GA.
- SCATTERED TO NUMEROUS AFTERNOON AND EVENING THUNDERSTORMS
TODAY. STRONG TO ISOLATED SEVERE STORMS ARE POSSIBLE, WITH
WIND GUSTS OF 40-60 MPH, FREQUENT LIGHTNING STRIKES, AND HEAVY
DOWNPOURS.
WESTERLY SURFACE WINDS CONTINUE TODAY AS THE MEAN LAYER RIDGE
INTO THE MID LEVELS IS OVER THE CENTRAL GULF. DEEP LAYER FLOW
UP THROUGH ABOUT 500 MB IS THE WEST OR NORTHWEST ABOUT 10-15 KT.
PWATS REMAIN ELEVATED AT ABOUT 2 INCHES OR SLIGHTLY HIGHER.
GUIDANCE SHOWS PERHAPS A BETTER CHANCE OF SHOWERS AND STORMS
THIS AFTERNOON AND EVENING THAN PRIOR FORECASTS. HOWEVER, THESE
HIGHER CHANCES, UP TO 40-60 PERCENT, ARE FOCUSED IN A
CONVERGENCE ZONE THAT APPEARS TO BE LOCATED ALONG THE I-10
CORRIDOR NORTHWARD TO HIGHWAY 82 IN SOUTHEAST GA. OUTSIDE SIDE
OF THESE AREAS, RAIN CHANCES LOOK TO BE 20-40 PERCENT. GIVEN THE
AMOUNT OF MOISTURE AND INSTABILITY, ISOLATED STRONG/SEVERE
STORMS ARE PROBABLE ESPECIALLY WITH ANY BOUNDARY COLLISIONS AND
MERGERS. LATEST MODEL SOUNDINGS SHOW MLCAPE THAT MAY BE UP TO
3000-3500 J/KG AND THE DOWNDRAFT CAPE THAT MAY BE NEAR 1000.
THAT SHOULD BE ENOUGH FOR GUSTS UP TO 40-60 MPH. THE SPC HAS
SHOWN A MARGINAL RISK OF SEVERE STORMS FOR MOST OF OUR AREA
TODAY. ISOLATED TO SCATTERED SHOWERS AND STORMS ARE ANTICIPATED
TONIGHT, AND WILL EVENTUALLY FADE AND DISSIPATE BY MIDNIGHT AND
WILL SHOW ONLY 10 PERCENT CHANCES AFTER MIDNIGHT.
BIGGEST CONCERN TODAY WILL BE DANGEROUSLY HOT TEMPERATURES AND
HEAT INDEX VALUES. HIGH TEMPERATURES WILL BE IN THE MID TO
UPPER 90S, EVEN AT THE EAST COAST BEACHES. MAXIMUM AFTERNOON
HEAT INDICES WILL BE AROUND 105-110 DEGREES. HEAT ADVISORY
REMAINS IN EFFECT.
SHORT TERM /THURSDAY 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.
HIGH PRESSURE OVER THE GULF WILL BEGIN TO SHIFT TOWARDS THE
NORTHERN GULF COAST LATE IN THE FORECAST PERIOD AS A TROUGH
SHIFTS SOUTH ALONG THE SE COAST. WITH THE HIGH PRESSURE OVER THE
GULF, WESTERLY- SOUTHWESTERLY FLOW WILL PERSIST THROUGH THE END
OF THE WEEK. SCATTERED SHOWERS AND STORMS ALONG THE GULF BREEZE
AS IT PUSHES INLAND, WITH HIGHER CHANCES FOR LOCATIONS SOUTH OF
THE I-10 CORRIDOR AS MOISTURE WILL BE SLIGHTLY HIGHER OVER NE
FL. THE ATLANTIC SEA BREEZE WILL BEGIN TO PUSH ONSHORE DURING
THE AFTERNOON HOURS, WITH COVERAGE OF SHOWERS AND STORMS EXPECT
TO INLAND FROM THE COAST OF SE GA AND NE FL AS THE SEA BREEZES
MERGE.
WARM TEMPERATURES WILL CONTINUE THROUGH THE END OF THE WEEK AS
DAYTIME HIGHS WILL REMAIN IN THE UPPER 90S, CLOSE TO 100F FOR
SOME LOCATIONS. A HEAT ADVISORY WILL LIKELY BE NEEDED FOR BOTH
DAYS. AN EXTREME HEAT WATCH IS CURRENTLY IN PLACE FOR COASTAL SE
GA AS HEAT INDEX VALUES MAY RISE TO 112F TO 114F THURSDAY
AFTERNOON.
LONG TERM /SATURDAY THROUGH TUESDAY/
MAIN HIGHLIGHTS THIS PERIOD:
- OPPRESSIVE HEAT CONTINUES DURING THE WEEKEND, WITH HEAT
ADVISORIES LIKELY.
A DIPPING COLD FRONT ALONG THE SE COAST WILL ALLOW FOR HIGHER
CHANCES OF SHOWERS AND STORMS ACROSS SE GA ON SATURDAY, AND THEN
SOUTH TOWARDS NE FL ON SUNDAY. COVERAGE OF SHOWERS AND STORMS
LOOK TO SHIFT FURTHER SOUTH TOWARDS NE FL ON MONDAY, AND BACK
NORTH AS THE FRONT DRIFTS NORTHWARD ON TUESDAY. ABOVE AVERAGE
TEMPERATURES WILL PERSIST INTO THE UPCOMING WEEKEND, WHERE WE
WILL CONTINUE TO HAVE TEMPERATURES RISE TO THE UPPER 90S AND
HEAT INDEX VALUES RISING TO HEAT ADVISORY CRITERIA DURING THE
AFTERNOON HOURS. BUT THE TIMING OF SHOWERS AND STORMS MAY KEEP
SOME LOCATIONS FROM RISING MUCH AS CLOUD COVER MAY LIMIT MUCH
HEATING TO TAKE PLACE.
AVIATION /12Z WEDNESDAY THROUGH 12Z THURSDAY/
VFR CONDITIONS WILL PREVAIL AT THE REGIONAL TERMINALS THROUGH AT
LEAST 18Z. SHOWERS AND THUNDERSTORMS WILL BEGIN DEVELOPING NEAR
THE DUVAL COUNTY TERMINALS AFTER 18Z, WITH ACTIVITY THEN
EXPANDING TO THE SSI AND SGJ COASTAL TERMINALS TOWARDS 20Z AND
THEN SOUTHWARD TOWARDS THE GNV TERMINAL BY AROUND 22Z. TEMPO
GROUPS WERE PLACED AT EACH TERMINAL FOR BRIEF WIND GUSTS UP TO
35 KNOTS, ALONG WITH IFR VISIBILITIES DURING HEAVIER DOWNPOURS.
CONVECTION SHOULD SHIFT SOUTHWARD AND AWAY FROM THE TERMINALS BY
01Z THIS EVENING, WITH VFR CONDITIONS THEN PREVAILING OVERNIGHT
THOUGH SUNRISE ON THURSDAY. WESTERLY SURFACE WINDS WILL BECOME
SUSTAINED AT 5-10 KNOTS AT THE REGIONAL TERMINALS BY 15Z,
FOLLOWED BY WINDS SHIFTING TO NORTHWESTERLY BY 17Z. THE ATLANTIC
SEA BREEZE WILL DEVELOP AFTER 18Z ALONG THE COAST, WITH THIS
BOUNDARY MOVING PAST THE SSI AND SGJ COASTAL TERMINALS BEFORE
20Z, SHIFTING SURFACE WINDS TO EAST- SOUTHEASTERLY AROUND 10
KNOTS AT SGJ AND SOUTHERLY AROUND 10 KNOTS AT SSI. AFTER
CONVECTION CONCLUDES, WEST-SOUTHWESTERLY SURFACE WINDS AROUND 5
KNOTS ARE FORECAST DURING THE OVERNIGHT HOURS.
MARINE
ATLANTIC HIGH PRESSURE WILL SHIFT SOUTH AND WESTWARD AS A TROUGH
FORMS OVER THE SOUTHEASTERN STATES. EACH AFTERNOON, THE SEA
BREEZE WILL SHIFT WINDS TO SOUTH TO SOUTHEAST OVER THE NEAR
SHORE WATERS THROUGH THE UPCOMING WEEKEND, FOLLOWED BY SOUTHERLY
EVENING WIND SURGES WHICH MAY BRIEFLY INCREASE TO NEAR CAUTION
LEVELS. SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS
WILL REMAIN POSSIBLE EACH DAY THROUGH THE UPCOMING WEEKEND. SOME
OF THESE STORMS MAY BE STRONG WITH GUSTY WINDS AND LOCALLY HIGH
WAVES.
RIP CURRENTS: LOW SURF HEIGHTS AT OR BELOW 2 FT AND OFFSHORE
FLOW WILL LIKELY YIELD A LOW RISK AT AREA BEACHES TODAY. THIS
PATTERN WILL LIKELY CONTINUE THROUGH FRIDAY.
FIRE WEATHER
- PATCHY HIGH AFTERNOON DISPERSIONS OVER SE GA TODAY AND
THURSDAY.
LIGHT WEST TO SOUTHWEST WINDS WILL KEEP THE ATLANTIC SEABREEZE
NEAR THE COAST EACH DAY, WITH LOWER THUNDERSTORM COVERAGE
EXPECTED TODAY. A FEW STRONG THUNDERSTORMS MAY PRODUCE GUSTY
OUTFLOWS WITH LOCALLY ERRATIC WINDS. WARM TEMPERATURES CONTINUE
AS HIGHS WILL BE IN THE MID 90S INLAND AND LOWER TO MID 90S AT
THE COAST TODAY. HEAT ADVISORY IS IN PLACE ACROSS NE FL AND
COASTAL LOCATIONS OF SE GA AS PEAK HEAT INDEX VALUES OF 106-112.
WITH WARM TEMPERATURES EXPECTED TO CONTINUE THROUGH THE REST OF
THE WEEK, HEAT ADVISORIES WILL LIKELY BE NEEDED. PATCHY HIGH
DAYTIME DISPERSIONS EXPECTED TODAY AND THURSDAY AS MIXING
HEIGHTS INCREASE 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.
CLIMATE
DAILY RECORD HIGH TEMPERATURES ARE POSSIBLE FROM THURSDAY
THROUGH SATURDAY:
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 94 75 96 77 / 30 10 10 10
SSI 95 78 97 80 / 40 20 20 10
JAX 95 76 97 76 / 60 20 40 10
SGJ 94 77 94 77 / 50 20 40 10
GNV 94 75 95 75 / 20 30 40 10
OCF 95 75 95 75 / 20 20 40 10
JAX WATCHES/WARNINGS/ADVISORIES
FL...HEAT ADVISORY FROM NOON TODAY TO 7 PM EDT THIS EVENING 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 NOON TODAY TO 7 PM EDT THIS EVENING FOR
GAZ153-154-162-165-166.
EXTREME HEAT WATCH FROM THURSDAY MORNING THROUGH THURSDAY
EVENING FOR GAZ153-154-165-166.
MARINE...NONE.
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