Area Forecast Discussion
Issued by NWS Jacksonville, FL
Issued by NWS Jacksonville, FL
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868 FXUS62 KJAX 201954 CCA AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 258 PM EDT Fri Sep 20 2024 ...New NEAR TERM, SHORT TERM, LONG TERM, AVIATION, MARINE, HYDROLOGY... ...DRIER WEEKEND WITH CONTINUED TIDAL FLOODING AND INCREASED RIP CURRENT RISK... .NEAR TERM... Issued at 228 PM EDT Fri Sep 20 2024 For the latest NE FL and SE GA Daily Key Messages please visit: https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf Widely scattered showers still expected across NE FL/Coastal SE GA this afternoon as the East Coast sea breeze pushes inland and Northeast winds increase to 10-15G20 mph, and while an isolated thunderstorm cannot be ruled out, storm chances remain around 10% or less through sunset. Light Northeast flow will remain in place tonight as weak high pressure builds north of the region, with winds remaining in the 5-10G15 mph range along the Atlantic Coast, but falling to 5 mph or less over inland areas under Mostly clear skies. This may be enough onshore flow to push a few of the showers over the Atlantic Coastal waters into the NE FL beachfront locations towards sunrise Saturday morning, but overall rainfall chances tonight remain along the coast remain around 20% or less. Further inland expect winds to become near calm towards sunrise Saturday morning & under mostly clear skies and temps falling into the upper 60s, expect at least some patchy fog development from the US 17/301 corridors inland to the I-75 corridor but too early to determine location of any locally dense fog development. Closer to the Atlantic Coast the onshore will keep milder conditions with lows in the lower/middle 70s. && .SHORT TERM... (Saturday through Sunday night) Issued at 228 PM EDT Fri Sep 20 2024 Breezy east to northeast winds and drier conditions will prevail this weekend with high pressure northeast of the region and weak coastal troughs offshore of the local Atlantic seaboard. The best chance of coastal showers will focus along the northeast FL Atlantic coast, with rain chances shifting inland into the afternoons where a thunderstorm will be possible generally south of a St. Augustine to Gainesville line. With drier air in place and mostly clear skies overnight, patchy to areas of inland fog are expected each night. High temperatures will trend near to above normal values in the 80s with mild lows in the upper 60s to low 70s. The main weather impact this weekend will be a continuation of Tidal Flooding along the local Atlantic coast, ICWW and within the St. Johns River basin. Most locations will top out in the "Minor" tidal flooding category, with a few locations along the St. Johns basin from Mayport toward the Trout River potentially nearing the "Moderate" threshold. At this time, the Coastal Flood Advisory to highlight mainly nuisance tidal flooding around high tides continues through the weekend. && .LONG TERM... (Monday through next Friday) Issued at 228 PM EDT Fri Sep 20 2024 Mon & Tue...A drier pattern continues through mid-week with a warming trend as an upper level ridge builds across the Gulf Coast region with a dry NNW flow aloft keeping frontal systems well north of the area and PWAT falling to < 1.2 inches by Tuesday. At the surface, the surface ridge will build southward with a ridge axis extending across the local area Monday and Tuesday continuing a dominant ESE flow and east coast sea breeze. Temperatures will moderate above normal values with highs in the low 90s well inland to mid 80s coast, with seasonally cool lows given the dry air with values in the mid 60s to low 70s. Wed & Thu...Moisture begins to return with a focus on the Gulf of Mexico and the ultimate evolution and track of a potential tropical system. Regardless of exact track, for the local area rain chances begin to increase with high temperatures trending lower with the increase in cloud cover and storminess. Use this weekend to restock supply kits and review family evacuation plans. Monitor official tropical forecasts from the National Hurricane Center at hurricanes.gov and local emergency management officials. && .AVIATION... (18Z TAFS) Issued at 119 PM EDT Fri Sep 20 2024 Northeast flow, diurnal heating and just enough moisture have allowed for some Towering Cu development and isolated showers (VCSH) along the East Coast sea breeze and have added to a few of NE FL TAF sites of JAX/VQQ/GNV for this afternoon, but this activity should end at JAX by 20Z, at VQQ by 21Z and sunset at GNV and continued to leave out any TSRA mention since chances remain low at this time (<10%). Light to near calm winds over inland TAF sites will support some fog formation in the 06-09Z time frame with IFR conds expected at VQQ and MVFR conds at GNV/JAX, but remaining VFR at the coastal TAF sites, lowest vsbys expected around sunrise. Conds improve in the 13-14Z time frame back to VFR conds and another more significant increase in NE winds late in the period will bring the chances for isolated showers (VCSH) to SGJ in the this period with potential for some MVFR CIGS as well. && .MARINE... Issued at 228 PM EDT Fri Sep 20 2024 Northeast winds will increase over the local waters tonight as an area of high pressure builds northeast of the region. As winds and seas increase late tonight into Saturday, Small Craft Exercise Caution conditions are expected. By Sunday, winds veer onshore as the high weakens and build ENE of the region. A weak pressure pattern develops Monday and continues through mid-week as high pressure extends offshore of the southeast Atlantic coast. 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... Issued at 228 PM EDT Fri Sep 20 2024 Minor coastal (tidal) flooding is will continue through the weekend for the Atlantic, ICWW and St. Johns River basin where a Coastal Flood Advisory is in effect. Flooding impacts will be mainly nuisance tidal flooding and greatest around times of high tide. High tide crests and inundation extended will subside Sunday into into Monday for most locations as astronomical departures decrease and onshore flow weakens. && .PRELIMINARY POINT TEMPS/POPS... AMG 67 87 67 89 / 10 0 0 0 SSI 73 82 73 84 / 10 0 0 0 JAX 70 85 72 88 / 10 10 10 10 SGJ 73 85 74 86 / 10 20 10 10 GNV 69 88 70 90 / 10 10 20 10 OCF 70 90 72 91 / 10 20 20 10 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...Coastal Flood Advisory until 5 AM EDT Sunday for FLZ033-038-124- 125-132-133-137-138-225-325. GA...Coastal Flood Advisory until 5 AM EDT Sunday for GAZ154-166. AM...None. && $$