Area Forecast Discussion
Issued by NWS Jacksonville, FL
Issued by NWS Jacksonville, FL
854 FXUS62 KJAX 160759 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 359 AM EDT Thu Jul 16 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 - Typically Hot and Humid Summertime Weather Continues through Friday. - Scattered Afternoon and Early Evening Showers and Thunderstorms through Friday. - Increasing Coverage of Showers and Thunderstorms this Weekend, Especially Across Northeast and North Central FL. - Heavy Downpours and Localized Flooding Possible on Sunday and Monday. - Potential Heat Advisory Conditions Towards the Middle Portion of Next Week. && .NEAR TERM /THROUGH TONIGHT/... Main Highlights Today and Tonight: - Typically Hot and Humid Summertime Weather Continues. - Scattered Afternoon and Early Evening Showers and Thunderstorms Today. Early morning surface analysis depicts high pressure (1021 millibars) situated just south of the northern Gulf coast. Meanwhile, a frontal boundary that was in place over the southeastern states was dissipating. Aloft..."Heat wave" ridging extends from the Upper Midwest southeastward across the Carolinas, with this feature flattening as troughing digs over the Great Lakes and New England. Beneath this ridge, a Tropical Upper Tropospheric Trough (TUTT) was spinning slowly northwestward across south FL and the FL Keys towards the southeast Gulf. Mid and high altitude debris cloudiness was gradually thinning out across our area, with light west winds keeping temperatures generally in the 75-80 degree range as of 08Z, with dewpoints mostly in the low to mid 70s. Ridging positioned over the Carolinas will continue to flatten as the aforementioned "TUTT" feature over south FL and the FL Keys slowly sharpens while drifting northwestward into the southeast Gulf by early Friday. Low and mid level northwesterly flow will otherwise continue through tonight as surface ridging just south of the northern Gulf coast slowly retrogrades westward. Seasonably hot and humid conditions will continue today, with inland highs climbing into the mid 90s, with a slightly delayed Atlantic sea breeze allowing highs to again reach the lower 90s at coastal locations. Heat index values will likely peak just below Heat Advisory criteria, with values generally in the 102-107 degree range this afternoon. Seasonable moisture levels should activate scattered convective development during the early to mid afternoon hours along mesoscale boundaries such as the inland moving Atlantic and Gulf sea breezes, with slightly higher PWATs compared to Wednesday perhaps increasing coverage across north central FL and the St. Johns River basin late this afternoon and early this evening as mesoscale boundaries collide near the U.S. Highway 17 and 301 corridors. A few storms may pulse as these boundaries collide, but relatively mild mid-level temperatures and weak lapse rates should keep any stronger storms that develop below severe limits. Stronger storms could produce downburst winds of 35-45 mph, along with frequent lightning strikes and heavy downpours, as storm motion today should be rather slow. Convection may drift further inland across the U.S.-301 corridor early this evening, but coverage should quickly diminish after sunset. Debris cloud cover will thin out towards midnight, with light low level westerly flow keeping lows mostly in the mid 70s inland and the upper 70s to around 80 at coastal locations. && .SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/... Main Highlights Friday through Sunday: - Heavy Rain and Localized Flood Concerns for NE FL this Weekend. - Daily bouts of showers and storms. Increasing afternoon thunderstorms is expected Friday as deep pooling moisture plasters the area. One factor for the Friday uptick in coverage will be the cooling temperatures aloft associated with a a tropical upper tropospheric trough closes off into upper low. The progression of the mid/upper level feature will likely bring numerous showers and thunderstorms across the NE FL zones Friday afternoon, initiating along the sea breezes. Due to the northwesterly flow the zone of sea breeze convergence will be generally along the US 301 corridor Friday. As the upper low closes, it`ll retrograde a bit farther northwest and anchor over the northeastern Gulf where it will sit until a northern stream trough dips across the eastern US, helping the low eject northeastward through Sunday. This feature will be the focus as a weak surface low may be reflected beneath the closed low, which may gradually become tropical in nature as it lifts northeastward on Sunday. The Nat`l Hurricane Center maintains only a 20% chance of tropical development with the latest guidance more pessimistic at surface low development. Whether a surface low develops or not, a tropical-like airmass will be in place especially for areas along the I-75 corridor. Heavy rain concerns will be the primary focus over the weekend with potential for localized flash flooding, mainly for NE and north central FL zones. Otherwise, seasonable summer heat will continue through the weekend, though cloud cover will associated with the low may cap highs in the upper 80s by Sunday. For Friday and Saturday highs in the low to mid 90s and heat index peaking in the 102-107 range is expected each afternoon. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... Main Highlights For Next Week: - Scattered to Numerous Afternoon Thunderstorms. - Potential heat advisory conditions by the middle of next week. If the the upper low lifts away according to the latest guidance, a west to southwesterly flow trailing it and deep moisture will keep chances fairly high 50-70% each afternoon through the first half of next week. Heat will will also build gradually through next week as upper ridging begins to nose in from the west-northwest. As peak temperatures push back into the mid 90s, the heat index may begin to approach Heat Advisory levels by the middle of next week. && .AVIATION /06Z THURSDAY THROUGH 06Z FRIDAY/... VFR conditions will prevail at the regional terminals through at least 17Z. Showers and thunderstorms will begin developing along the Atlantic and Gulf sea breeze boundaries towards 18Z, with activity developing initially near the SSI terminal and then potentially impacting the northeast FL terminals after 20Z. Confidence in timing and coverage remain too low for TEMPO groups at this time, but PROB30 groups for brief wind gusts up to 25 knots and MVFR visibilities during heavier downpours were included at each terminal, with possible impacts at the northeast FL terminals potentially extending through around 02Z Friday as the Atlantic and Gulf sea breeze boundaries potentially collide near the U.S. Highway 17 and 301 corridors. West-southwest or westerly surface winds will remain sustained around 5 knots overnight at the regional terminals, followed by surface winds shifting to northwesterly and increasing to 5-10 knots towards 14Z. Outside of developing convective, the inland moving Atlantic sea breeze will shift surface winds to easterly around 10 knots at SGJ towards and southeasterly at SSI by 19Z. The inland moving Gulf sea breeze will shift surface winds to westerly around 10 knots at GNV towards 21Z. West-southwesterly surface winds will then resume at the regional terminals by 02Z Friday, with speeds diminishing to 5 knots or less towards the end of this TAF period. && .MARINE... High pressure centered over the Gulf will maintain a prevailing northwesterly wind flow across our local waters through Friday, with the afternoon sea breeze shifting winds to east- southeasterly over the near shore waters, followed by a slight southerly evening wind surge throughout our waters after sunset. Showers and thunderstorms developing along the inland moving sea breeze late this afternoon may shift back over the near shore waters early this evening before dissipating. A similar weather pattern will continue on Friday, with mostly dry weather continuing offshore. Surface troughing will then develop over the southeastern states on Saturday, shifting prevailing winds to southwesterly, with southerly evening wind surges this weekend likely bringing at least Caution level wind speeds to our local waters. Surface troughing will continue to sharpen on 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 cyclone formation in the northeast Gulf. Showers and thunderstorms will increase in coverage this weekend, and this weak low pressure center may then progress northeastward across our local waters early next week. Rip Currents: Onshore winds developing this afternoon behind the inland moving sea breeze could create a lower end moderate risk at the northeast FL beaches, where surf heights may increase to around 2 feet. Meanwhile, low surf heights at the southeast GA beaches should maintain a low risk through at least Friday. 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... - Patchy High Dispersions Over Inland Northeast FL Today. Prevailing northwesterly transport and surface winds will keep the Atlantic sea breeze pushing beyond the I-95 corridor this afternoon. Due to the breezy northwesterly flow, patchy inland dispersions are likely, with high dispersions west of US 301. Shower and storm chances generally focus along the pinned Atlantic sea breeze late this afternoon but increase areawide Friday and into the weekend with a more active pattern emerging. This is partially due to potential tropical development in the northeast Gulf that we are currently monitoring. 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 93 75 94 74 / 20 10 40 30 SSI 93 78 93 79 / 40 20 10 10 JAX 94 74 94 75 / 50 20 30 20 SGJ 93 78 93 75 / 50 10 30 10 GNV 94 75 93 73 / 40 30 60 50 OCF 95 75 92 74 / 60 30 70 60 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. MARINE...None. && $$