Area Forecast Discussion
Issued by NWS Jacksonville, FL
Issued by NWS Jacksonville, FL
768 FXUS62 KJAX 132355 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 755 PM EDT Sun Jul 13 2025 ...New AVIATION... For the latest NE FL and SE GA Daily Key Messages please visit: https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf .AVIATION... (00Z TAFS) Issued at 756 PM EDT Sun Jul 13 2025 Strong thunderstorms will impact SSI and the Glynn County airfields through around 01Z, with brief surface wind gusts up to 30 knots and IFR conditions during heavier downpours. Thunderstorms may also impact GNV through around 02Z, with brief surface wind gusts up to 30 knots and IFR conditions during heavier downpours. Briefly heavy showers are otherwise possible through around 02Z at the Duval County terminals, with confidence high enough to include a TEMPO group at JAX for MVFR conditions through around 01Z. VFR conditions should then prevail at the regional terminals towards 03Z, with brief periods of MVFR visibilities possible overnight at VQQ. Showers and thunderstorms will focus inland on Monday afternoon and evening, with PROB30 groups for briefly gusty winds and MVFR to IFR conditions during heavier downpours included after 18Z at GNV and VQQ. Confidence was only high enough for vicinity coverage at JAX and CRG, generally during the early afternoon hours. Only vicinity showers were mentioned at the SSI and SGJ coastal terminals on Monday. Southerly surface winds sustained at 5-10 knots early this evening will shift to westerly while gradually diminishing overnight. Northwesterly surface winds will develop shortly after sunrise, with speeds increasing to 5-10 knots by 14Z. Surface winds will then shift to northeasterly at the coastal terminals by 16Z, where speeds will increase to around 10 knots. The Atlantic sea breeze will progress inland during the afternoon hours, shifting surface winds to northeasterly at the inland terminals by late afternoon. && .NEAR TERM... Issued at 146 PM EDT Sun Jul 13 2025 Weak low level troughiness is starting to make its way into the region and over area waters early this afternoon, with a northwest to north-northwesterly flow accompanying it for most. This flow direction is trying to advect some drier air into inland southeast GA near the Upper Suwannee River Valley and Altamaha Basin, which will make a little bit more progress inland through this evening and temper diurnal convection across this area. Towards the coasts and from about I-10 southward in northeast FL, layer moisture will hold strong, especially with a more east of north wind component closer to the coast which will result in more numerous convection this afternoon and evening. The Storm Prediction Center (SPC) has placed a good portion of the region, mainly northeast FL, in a marginal risk (1 out of 5) for isolated severe t`storms given the usual summer moisture and instability combined with slightly improved dynamics with low & mid level troughing. Primary potential hazard would be wet downbursts of up to 40-60 mph, though given very high CAPE and temps aloft near to slightly cooler than normal, isolated hail will also be possible. Strongest storms are likely to be closer to the east coast and the nearly pinned sea breeze, and as far inland as about HWY 301 in FL. Heavy downpours will also be a threat with the usual summer status quo, but a faster than normal and rare north to south storm motion will keep the flooding risk generally lower than the past few days unless excess training occurs. Offshore flow will also persist high temps a bit above normal, especially across interior southeast GA with less convective coverage. High temps in the mid 90s will be most common, with some readings in the upper 90s likely over interior GA. Convection may be slower to die down this evening and tonight with the presence of troughing near the coast and over area waters, with some showers and isolated thunder possible towards or after midnight - especially by the FL coast and over FL waters and south of about Gainesville to Saint Augustine. Mild lows in the mid to upper 70s will be common tonight. && .SHORT TERM... (Monday through Tuesday night) Issued at 146 PM EDT Sun Jul 13 2025 A broad area of low pressure is forecast to be off the southeast U.S. coast Monday morning, with an associated the mid/upper low pressure system located over the northwest Bahamas. A sfc trough extending from the low arcs northwest into GA. The sfc system is forecast to move west to west-southwest through the FL peninsula Monday through Monday night and then into the eastern Gulf Tuesday afternoon. Weak troughing, oriented from south to north over our forecast region, still likely on Tuesday even as the broad low moves west of the area late in the afternoon. Mean layer flow up to about 20 kft is northerly on Monday and shifts to northeasterly on Tuesday. On both days, highest chances for showers and storms are expected across inland areas as the Atlantic sea breeze will have little resistance moving inland, but especially on Tuesday as the low level flow become northeast and east. A few strong storms are likely with heavy rainfall, gusty winds, and frequent lightning. Models suggest Monday having the higher threat of heavy rainfall over inland areas south of I-10. WPC has marginal to a slight risk of excessive rain south of a line from about Palm Coast to Waldo to Fort White. Storm severity looks somewhat weaker by Tuesday as temps aloft are warmer and sfc temps may be more in the lower 90s which would suggest overall weaker updraft strength. The axis of better precip will also shift a little further inland on Tuesday due to northeasterly mean layer flow. Monday will be the hotter of the two days, with heat indices approaching advisory levels. Too close to call on issuing an advisory at this time. Forecast will show values of about 104 to 108 in most locations. Heat advisory criteria is 108-112. && .LONG TERM... (Wednesday through next Sunday) Issued at 146 PM EDT Sun Jul 13 2025 The broad area of low pressure will be in the Gulf on Wednesday with mean layer flow from the south and southeast. High pressure ridge axis will located further north than normal into parts of GA and SC Wednesday. As the sfc low tracks further away from the area Thu and Fri, this high pressure ridge will build further into the area by the end of the week. Elevated rain chances expected Wednesday to Friday with some moderation in chances nearer to normal by Sat due to subsidence affects from the mid level high which will move into central FL end of the week. Temperatures will be near to a little above normal this period with heat indices in the range of 100-105 each day, with heat advisory criteria possibly being met in some locations. && .MARINE... Issued at 146 PM EDT Sun Jul 13 2025 Atlantic high pressure will weaken and shift southward through tonight as a weak trough/broad low develops near the Gulf Stream waters. This feature will then slowly migrate westward across our local waters on Monday, followed by shifting westward into the northeast Gulf of Mexico by Tuesday. Showers and thunderstorms will remain scattered to numerous at times across our local waters beginning through Monday and Tuesday, with more northerly prevailing winds shifting to southerly by Tuesday as this trough slowly organizes over the eastern Gulf towards midweek. Rip Currents: Rip current risk is low to moderate through the rest of today with offshore or along shore flow. Risk will be moderate at all beaches Monday. && .PRELIMINARY POINT TEMPS/POPS... AMG 75 98 74 93 / 20 60 20 60 SSI 78 91 78 88 / 30 30 10 50 JAX 76 95 75 92 / 20 50 20 70 SGJ 75 91 77 89 / 40 30 20 70 GNV 75 97 73 93 / 60 80 40 80 OCF 75 96 73 91 / 60 80 40 90 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$