Area Forecast Discussion
Issued by NWS Jacksonville, FL
Issued by NWS Jacksonville, FL
208 FXUS62 KJAX 121811 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 211 PM EDT Sat Jul 12 2025 ...New NEAR TERM, SHORT TERM, LONG TERM, AVIATION, MARINE... .NEAR TERM... (Rest of Today through Tonight) Issued at 205 PM EDT Sat Jul 12 2025 For the latest NE FL and SE GA Daily Key Messages please visit: https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf Mid level ridge is located from the central Gulf coast southeastward to south FL, with broad troughing across SC/NC southward into the far western Atlantic. The troughing offshore will dig through tonight, while the mid level ridge will retrograde slightly. This will result in mean layer winds to veer a bit through tonight. At the sfc, weak high pres ridge over south central FL will shift southward, while weak troughing will develop further offshore of the southeast U.S. coast, more or less tied to a weak 1015 mb low pressure system developing along the SC/NC state line. Locally, for the rest of the afternoon, generally expect scattered showers and storms that will be moving slightly faster than yesterday, to the east or east-southeast. Expect that a few of these storms will move into the area coastal waters as well. Overall, convective parameters are not too far off from normal with MLCAPE and DCAPE of near 2700 J/kg and 800-1000 J/kg, respectively. We can`t rule a severe storm with a downburst winds to 50, possibly 60 mph, given the relatively favorable environment (compared to yesterday). Thete-E differences are in the neighborhood of 25-30. While most of the deep convection will diminish and tend to dissipate in the evening, the fact that we have some energy rotating around the mid level ridge late tonight across parts of the forecast area late tonight, isolated convection is likely late tonight. This convection will probably be on the weak side. Indeed, almost all the model guidance has some precip falling after midnight mainly central and eastern parts of the area. Again, this activity, should move toward the southeast as the mean flow veers into Sunday morning. Temps: in the lower to mid 90s rest of the aftn, and latest heat indices generally range from 101-106, with a few higher values out there but are suspect observations. Some of the precip occurring now may bring down indices a few values in some locations. Lows tonight in the mid 70s mostly. && .SHORT TERM... (Sunday through Monday night) Issued at 205 PM EDT Sat Jul 12 2025 Rather weak troughing/broad low pressure starts to shift south and southwestward from the Carolinas on Sunday, slowly moving towards and over the Florida Peninsula through Monday and Monday Night. This will have several implications, firstly breaking down high pressure ridging that has kept us in a mostly west to southwest flow, and secondly increasing rain/t`storm coverage across most of the area. The low will induce more of a northwesterly flow on Sunday, which will try to bring in some drier air into southeast GA and therefore tempering PoPs and convective coverage a bit in those areas, however. The more north to northwesterly flow near the surface and aloft will also result in a rather rare summer north to south storm motion Sunday. Highest convective coverage as well as the greatest threat for any strong to isolated severe storms will therefore be across northeast FL, and especially south of I-10 and towards the FL coast where the best convergence will be. Gusts up to 40-60 mph and minor flooding from heavy rainfall will be the primary hazards. Highs will remain quite warm with offshore flow, as mid 90s will be common. The highest readings likely to be across inland GA with less convective coverage and some drier air where upper 90s will be in store for some. As low pressure continues to push southward Sunday Night, this will likely keep some showers and t`storms going throughout the night over area waters and especially offshore waters, as well as over parts of northeast FL. Low temps will be mild Sunday Night, in the mid to upper 70s. Monday, broad low pressure will be located almost directly over north FL before slowly drifting southwestward towards the northeast Gulf Monday Night. The presence of the low and some weak energy aloft will maintain active convection, including increased coverage likely into southeast GA as well. The position of the low will shift flow towards the north to northeast throughout the day, with the east coast sea breeze therefore progressing far inland and likely shifting the "corridor" of highest PoPs and stronger t`storm chances inland and towards the nearly pinned west coast sea breeze during the afternoon and evening. More of a continental wind direction will hold strong enough inland for mid to upper 90s to continue Monday. However, temps from about the I-95 corridor and to the coast will nudge down a bit closer to the lower 90s where there will be more of a sea breeze influence. && .LONG TERM... (Tuesday through next Saturday) Issued at 205 PM EDT Sat Jul 12 2025 The broad and weak low will drift southwestward into the Gulf Tuesday and into Wednesday as high pressure starts to rebuild from the east to northeast through the end of the week. The National Hurricane Center (NHC) has placed a 20% chance of tropical or subtropical development somewhere over the north/northeast Gulf during the longer term, though impacts, if any, do not look significant and likely west of our area at this time. We will of course continue to keep a close eye on trends and forecasts accordingly. Otherwise, the long term looks to mostly consist of near to above average shower/t`storm chances and an onshore flow regime. Temperatures overall will trend near normal, though start to nudge upward towards late week as flow becomes more southeast as compared to east/northeast. && .AVIATION... (18Z TAFS) Issued at 205 PM EDT Sat Jul 12 2025 Scattered convection has developed over northeast FL so far this afternoon with activity nearing GNV at 2 PM. All the TAFs will have VCSH/VCTS rest of the aftn with TEMPO groups, and MVFR and possible IFR at this time with gusts of 25-30 kt. Convection will linger 00z-03z this evening and fade. However, based on chances of showers and storms in the forecast after midnight, have opted to leave in VCSH for SGJ and CRG after 04z. May need additional VC wording in SSI too later tonight, but too uncertain for now. For Sunday, expect another round of showers and storms, with some better chances for northeast FL, thus seems warranted to go with a PROB30 group for GNV 15z-18z. && .MARINE... Issued at 205 PM EDT Sat Jul 12 2025 High pressure extending across central Florida will move south through Monday while a surface trough develops over portions of the area coastal waters. The surface trough will move west of the area by early Tuesday. Scattered thunderstorms will be possible each day over area waters. Some storms may produce strong gusty winds and frequent lightning. Winds of 10-15 kt or less and seas of 3 ft or less anticipated into Sunday and probably Monday. Some slight uptick in in the winds and seas are likely by Tuesday and Wednesday, with the wind flow becoming more east and southeast. Rip Currents: Low to moderate risk of rip currents continues with surf/breakers around 2 feet, with a slight subsiding trend to 1-2 feet by Sunday/Monday, with low to moderate risk of rip currents continuing. && .PRELIMINARY POINT TEMPS/POPS... AMG 74 96 75 96 / 20 20 20 50 SSI 77 93 79 92 / 30 30 20 40 JAX 75 96 76 95 / 30 60 20 70 SGJ 76 94 76 92 / 30 70 30 70 GNV 75 95 74 96 / 20 70 20 90 OCF 75 93 76 94 / 20 80 30 90 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$