Area Forecast Discussion
Issued by NWS Jacksonville, FL
Issued by NWS Jacksonville, FL
070 FXUS62 KJAX 121336 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 936 AM EDT Sat Sep 12 2026 .KEY MESSAGES... For the latest NE FL and SE GA Daily Key Messages please visit: https:/www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf - Moderate Rip Current Risk all Local Beaches Today and Friday. Elevated Risk Returns Early Next Week - Daily Heat Index up to 107 through Sunday - Daily Afternoon & Evening Thunderstorms. Main Hazards: Locally Heavy Rain, Lightning & Gusty Winds Up to 40-50 mph && .UPDATE... Some adjustment with thunderstorm chances and timing were completed with this morning update. Overall a similar pattern will set up today with a "juicier" profile compared to 24 hours ago; JAX 12z RAOB measured PWAT at 2.36". A persistent southwesterly flow with deeper westerly flow aloft will again hold the Atlantic sea breeze off early this afternoon and promote a fast-moving Gulf sea breeze. During the late afternoon and early evening hours, 4-7 PM, the sea breezes will interact and again lead to numerous thunderstorm development along the I-95 corridor. Given the locally high amounts (2"+) of rain less than 24 hours ago, there will be potential for localized flooding. Additionally, precip loaded downdrafts may lead to strong outflow winds up to 50 mph along with potential for excessive lightning. By this evening, a shortwave will approach the region from the northwest which may continue convection through midnight for portions of southeast GA, mainly north of Waycross. It`s unlikely this trough will dip any farther south as it should largely be deflect to the northeast by the stubborn mid level ridge. Temperatures today will be hot again, pushing into the low 90s, allowing heat index to climb to 100-106 degrees this afternoon. && .AVIATION /12Z SATURDAY THROUGH 12Z SUNDAY/... Mostly VFR conditions with cumulus development after 15z, possibly with brief MVFR ceilings (2-3k ft). Showers and storms likely starting at 16z, and then become more numerous after 18z through around 23z. Confidence in TSRA impacts remains high with TEMPO and PROB30 betweeen 18z-24z at all terminals. Non-thunderstorm winds will be light southwest to west, with east coast sea breeze developing at SGJ, CRG, and SSI by 18z. Sea breeze may reach JAX by 22z if not disrupted by convection during the early/mid afternoon. && .MARINE... Weakening high pressure south of the area will maintain south to southwest winds and afternoon sea breezes through the weekend. Daily mid to late afternoon thunderstorms will move offshore, bringing locally strong wind gusts and frequent lightning at times. On Tuesday, high pressure ridge will push south along the east coast and push a cold front south through the area waters, creating strengthening northeast winds and building seas. This may lead to a small craft advisory for the coastal waters starting Tuesday and may continue into Wednesday and Thursday. Rip Currents: Prevailing offshore winds (except for an afternoon sea breeze) and weak easterly swells will keep a low-end moderate risk of rip currents in effect the next couple of days. Strengthening northeast winds late Monday night into Tuesday will likely result in a high risk at all area beaches through at least Thursday as breakers build. && .FIRE WEATHER... A trough of low pressure will stretch across the southeastern US this weekend. High pressure will build to the northeast early next week, and strengthen through mid week. As this high builds, an inverted trough will develop east of the area. The gradient between these two features will result in elevated winds Tuesday through Thursday, especially at the coast. An inverted trough will settle overhead late in the week into the weekend. Daily thunderstorm chances are forecast, mainly in the afternoon and evening hours. && .HYDROLOGY... As far as rainfall today into tonight, areal amounts of around 0.2 to 0.5 inches are forecast. Many areas may see less than that. However, model guidance shows some amounts of about 3 inches are possible in a few pockets mainly over the eastern zones, but also shown to be possible toward Alachua and Marion counties. As such, where these heavy rains occur today, temporary flooding is possible, especially in any poor drainage or urbanized areas. && .PRELIMINARY POINT TEMPS/POPS... AMG 91 73 92 72 / 50 30 20 0 SSI 89 77 91 77 / 60 30 30 10 JAX 91 74 92 75 / 70 20 50 10 SGJ 90 75 91 75 / 60 20 50 20 GNV 91 73 91 74 / 60 20 50 10 OCF 92 74 92 74 / 50 20 60 20 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. MARINE...None. && $$