Area Forecast Discussion
Issued by NWS Jacksonville, FL
Issued by NWS Jacksonville, FL
077 FXUS62 KJAX 181202 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 802 AM EDT Sat Jul 18 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 - Low chance (30%) of a tropical development in the northeastern Gulf through Monday. - Scattered afternoon thunderstorms this weekend followed by expanding coverage by Monday with increasing potential for heavy rain and localized flooding. - Moderate Rip Current Risk today and Sunday - Heat Advisory Conditions Possible Towards the Middle of Next Week && .NEAR TERM /THROUGH TONIGHT/... Main Highlights This afternoon and Tonight: - Seasonably Hot and Humid Summertime Weather Continues. - Scattered thunderstorms with isolated strong storms possible for Suwannee River Valley and inland Southeast GA. Elevated and slow-moving showers and isolated thunderstorms continue to develop amid residual elevated instability, mainly north of I-10, early this morning. The primary driver of these showers appears to be broad lift associated with weak positive vorticity advection around the closed upper level low of the southwestern coast of FL. Due to slow moving nature of these isolated thunderstorms and premium moisture in place, there is a chance for localized flooding over the next few hours. For Today...low level steering flow will trend southerly and then southwesterly through the afternoon as the Bermuda high extends an axis across southern FL and the upper low shifts slightly west. This will keep the Atlantic sea breeze from pushing as far inland this afternoon. Overall, convective coverage will be limited across NE FL this afternoon as a dry pocket of air wrapping around the base of the upper low this morning lifts northward into the area this morning/afternoon. Though the dry pocket will curtail instability, there should be sufficient moisture across interior areas of SE GA and northern tier of the Suwannee River valley, generally northwest of Waycross and west of Lake City, to support scattered thunderstorm development this afternoon. With the sea breeze being pinned temperatures will be hotter for communities closer to the coast today with highs into the mid 90s. The beaches should still feel the cooling sea breeze, limiting highs to the low 90s. Heat index values will generally peak in the 100-107 degree range once again. Tonight...A few showers and possibly an isolated thunderstorm may develop this evening along outflow produced by convection across central FL for the north-central FL zones this evening. Otherwise, convection will generally fade more quickly tonight with less elevated instability to feed off. Additionally, guidance does indicate a surface low may begin to organize in the northeastern Gulf beneath the upper low. This low remains a potential candidate for tropical development through Sunday with now a 30% chance of developing. Please continue to monitor for updates and emerging forecast information on what could become the second Atlantic tropical system of the 2026 season. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... Main Highlights This Period: - Heavy Rain and Localized Flood Concerns - Daily bouts of showers and storms The main focus for the forecast period will be on the potential for further development of an upper level low (NHC has a 30% chance of tropical development during the next 7 days) currently located off the west coast of FL in the Gulf. Regardless of further development, the deep tropical airmass hanging over the area (PWATs around 2") with cooling temps aloft will support rounds of showers and thunderstorms during the afternoon and evening hours. The highest convective coverage and heavy rainfall amounts will likely be over inland areas, as the east coast sea breeze moves inland and keeps the bulk of the heavier storms further west and away from the Atlantic coast. Latest CAMs indicate the Low to remain a bit longer over the NE Gulf and shift a little to the west before any shift towards the north/northeast at the start of the upcoming week, when coverage of showers and storms is expected to increase on Monday for inland locations of NE FL and SE GA. Temperature highs will be in the lower to mid 90s through the end of the weekend and the start of the upcoming week, with peak heat index values of 102 to 107 degrees. && .LONG TERM /TUESDAY THROUGH FRIDAY/... Main Highlights This Period: - Scattered to Numerous Afternoon Thunderstorms - Potential heat advisory conditions by the middle of next week Nearing midweek, the upper level disturbance in the Gulf is expected to weaken as low to mid level ridging builds over the FL peninsula by Wednesday as the low pressure shifts northward. Otherwise, will continue to see scattered to numerous chances for showers and storms through the upcoming week, with coverage increasing across the area as a frontal boundary nears the region during the later part of the upcoming week. Temperatures will again rise to the low to mid 90s during the afternoon hours during the week ahead as heat index values will begin to trend into the 105 to 110 range by midweek. && .AVIATION /12Z SATURDAY THROUGH 12Z SUNDAY/... Lingering stratus at GNV will gradually lift and dissipate in the next couple of hours. Low chance of showers and storms near the TAF sites this afternoon intro evening due to the pocket of dry air moving northward into the area. An isolated low-topped shower could pass near the TAF sites so kept VCSH. Atlantic sea breeze will gradually shift winds south-southeasterly across KSSI, KSGJ and KCRG at around 10 knots. Otherwise, a south-southwesterly wind will prevail at TAF sites west of I-95. && .MARINE... Bermuda high pressure will extend a ridge axis across southern Florida today, shifting winds southerly across the local waters today. As winds shift they will strengthen to Exercise Caution levels between a trough over the southeastern US and the ridge axis to the south. Drier air moving into the coastal waters will limit thunderstorm potential through the weekend and possibly into next week. There`s greater uncertainty in the forecast next week regarding the potential for tropical development in the northeastern Gulf. That system is now more likely to drift northwest through the first half of next week. For the second half of next week, a prolonged offshore flow is likely to remain in place with nocturnal southerly wind surges as a cold front approaches from the northwest. Rip Currents: There will be a moderate risk for rip currents this afternoon as surf elevate to 2-3 feet along the SE GA beaches and 2-4 feet for NE FL beaches. Surf heights will relax some Sunday but a moderate risk is still expected during the afternoon. && .FIRE WEATHER... Tropical moisture increasing over the region will bring rain and storm chances through the weekend, with rounds of heavy downpours heading into the upcoming week, bringing the potential for localized flooding with any training showers and storms. South-southwest surface and transport winds increase this weekend improving dispersions to the fair to generally good range. Fog Potential and Other Remarks: Significant fog development is not expected for the next several nights. Gusty and erratic winds will be possible in and near thunderstorms, with occasional outflow boundaries capable of producing sudden wind shifts well away from ongoing convection. && .PRELIMINARY POINT TEMPS/POPS... AMG 93 73 93 74 / 50 30 40 10 SSI 90 78 93 79 / 20 20 20 10 JAX 95 76 94 76 / 20 10 30 10 SGJ 93 76 92 76 / 10 10 30 10 GNV 92 73 91 73 / 20 10 50 20 OCF 92 74 91 74 / 20 20 60 20 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. MARINE...None. && $$