FXUS62 KJAX 271343 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 943 AM EDT Tue May 27 2025 ...New UPDATE... .UPDATE... Issued at 930 AM EDT Tue May 27 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 Fairly small area of patchy dense fog is finally dissipating near and just north of the JAX airport. We updated forecasts to account for this morning. We also have some lingering isolated shower activity near the Altamaha River Basin and is slowly pushing off to the east-northeast, and appears its related to a weak shortwave trough. Recent guidance shows that an uptick in convection will occur along the Atlantic sea breeze this afternoon and early evening, mainly across northeast FL St Johns River Basin. This may be a bit more coverage through the evening. Further north, should see some scattered convection across parts of southeast GA mainly north of Waycross as 1 or 2 shortwave troughs moves across parts of central GA. Time frame for this convection will be later, roughly from 9 PM to about 1 AM. In both areas, model soundings suggest about 25 to near 30 kt of effective shear, narrow CAPE, and decent DCAPE. This may support isolated hail and a damaging wind threat. Noticing 500 mb temp from JAX sounding at -5.3C so this may result in any isolated severe storms confined to inland southeast GA where the 500 mb temps are cooler at about -7/-8C. Max temps were adjusted slightly. Otherwise, previous forecast looks good with just slight adjustments. && .NEAR TERM...(Today and Tonight) The last bit of convection that has held together through the early morning hours is beginning to diminish. Dry conditions areawide and perhaps some patchy and light fog is expected by sunrise. For today, a deep southwesterly steering flow will focus an intrusion of drier mid level air across most of the area this afternoon, cutting available moisture down substantially, with PWAT under 1.5". The drier air aloft combined with subsidence will limit sea breeze shower development this afternoon. Though a few showers may develop along the sea breeze, mainly during the late afternoon, it'll shift east off the coast as it diminishes around or before sunset. The main window of convective activity today is expected across SE GA this evening and possible into the early hours Wednesday as another shortwave impulse rides along a persistent boundary near the Altamaha River basin. A complex of thunderstorms associated with the feature will push west to east into and across SE GA after sunset. Residual instability developed throughout the day should leave enough fuel to support a mix of surface-based and elevated convection with the capacity to become strong or marginally severe, particularly as it interacts with the lingering remnants of the sea breeze boundary. Primary concerns with these storms will be strong wind gusts (40-60 mph) and localized flooding, especially in urban areas along the SE GA coast. Offshore flow and a dominant Gulf sea breeze will lead to another widespread day of heat with highs in the low to mid 90s and heat index values in the lower 100s. While significant fog development isn't likely, there could be patches of fog in areas where heavy rain occurs this afternoon and evening. && .SHORT TERM...(Wednesday through Thursday night) Hot days with diurnally driven showers and thunderstorms continue Wednesday and Thursday. SW return flow increases moisture to the area and continues a dominant Gulf sea breeze regime. Showers and thunderstorms develop along the inland moving sea breezes each late morning into evening. Widely scattered convection on Wednesday gives way to more numerous activity on Thursday with the increase in low-level moisture. Isolated strong to pulse severe storms will be possible due to additional lift from passing upper shortwaves and along the sea breeze merger near the I-95 corridor each afternoon and evening. Above seasonable temperatures continue with highs in the upper 80s to mid 90s and overnight lows in the upper 60s to low 70s. && .LONG TERM...(Friday through Monday) A deepening trough will shift a cool front into the area Friday night into Saturday. Moist SW flow will increase PWATs across the area to about 2 inches on Friday ahead of the approaching front. Pre-frontal convection will be more widespread compared to previous days bringing beneficial to potentially flooding rainfall area-wide Friday into Friday night. Embedded strong to severe thunderstorms will be possible with additional lift from passing shortwaves aloft. Cooler, drier air filters in from the northwest as the cool front shifts south of the area on Saturday. Temperatures cool below seasonable for the weekend with highs in the 80s to around 90 and overnight lows in the 60s. && .AVIATION...(12Z TAFS) Issued at 641 AM EDT Tue May 27 2025 Low stratus and sporadic areas of fog will continue MVFR cigs and IFR/LIFR visibility around 13z, lifting to VFR thereafter. Widely scattered convection and isolated thunderstorms are possible but confidence not quite high enough at this point to justify prevailing or temporary conditions at any specific site in NE FL. Better thunderstorm chances are expected this evening at KSSI between 03-06z. Winds this morning will favor WSW and then shift ESE with the Atlantic sea breeze advances inland. && .MARINE... Broad high pressure ridge will remain over the waters today while a weak and stationary front resides just to the north. A weak trough of low pressure will track along the front this evening and increase thunderstorm potential over the Georgia coastal waters tonight. A light flow pattern will allow the sea breeze to develop each afternoon through Thursday with increasing chances for storms along it by Thursday afternoon. Offshore winds will strengthen Friday in response to an approaching cool front. The frontal passage is expected Friday night and will be accompanied by a strong or possibly severe line of storms. Rip Currents: Lower-end Moderate Risk today and Wednesday. && .FIRE WEATHER... Widely scattered showers and thunderstorms will develop again in the vicinity of weak stalled front across southeast Georgia and along the sea breeze fronts today and Wednesday. Despite the downpours, frequent lightning may lead to new ignitions across Marion, Putnam and Flagler counties where fuels are driest. Hot and humid conditions with high mixing heights continue through the week. Southwesterly transport winds increase on Thursday ahead of a cool front moving through the southeast US resulting in area- wide high daytime dispersions. A strong to severe line of thunderstorms will push into the area ahead of cool front Friday or Friday night. Rain and thunderstorm potential will drop behind the cool front for the weekend as drier air begins to filter in. && .PRELIMINARY POINT TEMPS/POPS... AMG 91 69 90 70 / 30 40 30 30 SSI 85 74 89 74 / 30 40 30 40 JAX 93 72 94 72 / 30 20 40 20 SGJ 90 73 93 73 / 30 20 40 20 GNV 94 71 94 71 / 30 20 30 10 OCF 94 71 94 71 / 40 20 20 10 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$