Area Forecast Discussion
Issued by NWS Jacksonville, FL
Issued by NWS Jacksonville, FL
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171 FXUS62 KJAX 200809 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 409 AM EDT Fri Sep 20 2024 ...MINOR COASTAL FLOODING THROUGH THE WEEKEND... .NEAR TERM...(through Tonight)... Light fog has started to develop across portions of southeast GA near the Altamaha river. Amid clear skies and calm conditions, it`s possible for locally dense fog to develop toward sunrise across inland areas of SE GA north of Waycross. A weak boundary stalled across north central FL will become more diffuse through the day while a surface ridge builds to the north. Though forecast soundings are offering generous diurnal instability (SBCAPE ~1500 j/kg) this afternoon, the dry air aloft will keep PoPs isolated at best and focused across north-central FL. Any lingering showers this evening will fade quickly and be followed by mostly clear skies which may allow patchy fog development inland early Saturday. The onshore flow will keep the beaches cooler today with temps peaking around the low/mid 80s while inland areas push into the upper 80s. For the latest NE FL and SE GA Daily Key Messages please visit: https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf && .SHORT TERM...(Saturday through Sunday night) Breezy northeasterly flow through the weekend as high pressure continues to build over the region. Drier air (PWATs <=1.5") over the area will limit precipitation chances through the weekend for most locations. Northeasterly flow may bring some showers and storms onshore along coastal locations south of the JAX metro during the afternoon both Saturday and Sunday, with PoPs currently around the 20% to 35% range. The coastal flood advisory will remain in place through Saturday evening as the combination of northeasterly flow and high tide will bring about some minor flooding along the coast. Temperature highs for this weekend will be in the mid to upper 80s, with Sunday expected to be slightly warmer as the northeasterly flow begins to weaken a bit. Overnight lows again expected to be in the upper 60s for locations across SE GA and in the lower 70s across NE FL. && .LONG TERM...(Monday through Thursday night) The dry weather will continue during the early half of the upcoming week as the dry airmass and high pressure is expected to remain over the region into Tuesday. Uncertainty in the development of a tropical cyclone over the northwestern Caribbean Sea during the upcoming week leaves the back half of the forecast period still in question. With the models differing in the evolution of the eastward moving trough from the High Plains has led to run-to-run shiftiness and a wide envelope of possible tracks among the ensemble models. At this time, NHC still has chance of development at 40% for the area in the northwestern Caribbean Sea. && .AVIATION...(06Z TAFS) Issued at 154 AM EDT Fri Sep 20 2024 Aside from patchy fog this morning at inland airfields (KVQQ & KGNV), VFR conditions are expected through the period. Winds will favor a northeast direction at 5-12 knots through the day with speeds tailing off this evening. An isolated afternoon shower may develop along a sea breeze boundary with best probability at KGNV, which is still under 20%. && .MARINE... Northeast winds will increase today as an area of high pressure builds from the north. As winds and seas build, small craft will need to exercise caution on the local waters through Saturday. By Sunday, flow turns onshore through as the high weakens and settles to the northeast. A weak pressure pattern will set up through the first half of next week before a cold front approaches from the northwest during the latter part of next week. RIP CURRENTS...There will be a moderate risk of rip currents today with risk increasing to High by Saturday as surf heights rise amid the breezy onshore flow. && .HYDROLOGY... Due to the compounding effects of lingering runoff from recent heavy rains, onshore flow, and high astronomical "spring" tides, minor coastal flooding is anticipated this morning and likely through the weekend. The flooding potential will be greatest around times of high tide. A Coastal Flood Advisory continues for the St Johns River basin (including the Intracoastal Waterway) and Atlantic coast of NE FL. This morning the Advisory has been expanded northward to cover the stretch of the SE GA beaches/sounds Tidal flooding should lower through Sunday and into Monday as astronomical departures decrease and onshore flow eases up. && .PRELIMINARY POINT TEMPS/POPS... AMG 88 67 87 67 / 10 0 0 0 SSI 83 73 82 73 / 10 0 0 0 JAX 87 71 85 72 / 20 10 10 0 SGJ 86 74 85 74 / 10 20 30 10 GNV 89 69 88 70 / 20 0 10 0 OCF 91 71 90 72 / 20 0 20 0 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...Coastal Flood Advisory until 5 AM EDT Sunday for FLZ033-038-125- 132-137-225-325. Coastal Flood Advisory until 5 AM EDT Sunday for FLZ124-133-138. GA...Coastal Flood Advisory until 5 AM EDT Sunday for GAZ154-166. AM...None. && $$