Area Forecast Discussion
Issued by NWS Jacksonville, FL
Issued by NWS Jacksonville, FL
051 FXUS62 KJAX 130546 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 146 AM EDT Sun Sep 13 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 - Scattered Afternoon and Early Evening Thunderstorms Expected today. Strong Storms are Possible Along the I-95 Corridor, with Wind Gusts of 40-50 mph Possible, Along with Frequent Lightning Strikes and Torrential Downpours. - Daily Heat Index Values Peak in the 104 - 108F Range through Monday - Afternoon and Evening Thunderstorm Coverage Shifts South of the I-10 Corridor on Monday. - Becoming Breezy and Cooler on Tuesday at Coastal Locations with Numerous Showers and Embedded Thunderstorms Possible. - Small Craft Advisory Conditions Expected Tuesday through Thursday Across Our Local Atlantic Waters. High Risk of Rip Currents is Likely at Area Beaches. && .NEAR TERM /TODAY THROUGH TONIGHT/... Main Highlights This Period: - A few strong storms possible, with gusty winds and heavy rainfall - Heat indices up to 108 today - Patchy fog this morning and tonight A few changes in the pattern today as a mid level trough swings southeastward into the area today, with an associated low level trough moves into southeast GA as well. This will bring about mean layer steering flow changing from southwest to west during the day. In addition, drier air will filter into inland southeast GA north of Waycross as PWATs drop below 2 inches there, but remain elevated elsewhere to about 2.0 to 2.3 inches. This moisture and the instability available will fuel additional shower and storm activity today. Convection will likely start early for inland northeast FL, then work east through the afternoon. The greatest chance for storms today will be along the I-95 corridor due to sea breeze interactions. Much lower rain chances are advertised for southeast GA at about 20-30 percent, where forcing is weaker and drier air will work against deep convection formation. For northeast FL, will initialize POPs at about 30-60 percent, with lowest chance toward north Suwannee and Hamilton counties, and highest chance over the southern St Johns River Basin. Isolated strong storms are possible this afternoon, mainly where the forcing is strongest over the southeast zones, with strong gusty winds, frequent lightning, and heavy rainfall the main concerns. DCAPE remains limited again to about 600 J/kg, and MLCAPE up to near 2500 J/kg. Peak rainfall amounts not as high as prior days, but up to 3 inches are still possible. Isolated to widely scattered convection expected in the evening from 8 pm to midnight, and as usual on a weakening trend, dissipating by that time. Patchy fog expected inland areas early this morning and again early Monday morning. Locally dense fog is possible. Temperatures hot again today and up to 2-4 deg above seasonal averages, with heat indices up to 104 to 108. Lows tonight in the lower to mid 70s. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... Main Highlights This Period: - Daily Thunderstorm Potential Monday and Tuesday, with a few strong storms possible capable of producing gusty winds and heavy rainfall Prevailing flow will shift about to become more out of the northeast by Monday night as ridging moves northward and high pressure forms north of Georgia. Diurnal convection will become inhibited over southeast Georgia as drier air and high pressure ridging extends into the northern portion of the forecast area, inhibiting the development of showers and storms, with storms more likely to form over north central Florida and for areas south of the I-10 corridor. Northeasterly flow will be more entrenched on Tuesday with daytime convection and breezy winds, strengthened by the tightening pressure gradient, pushing onshore and pressing inland. High temperatures will rise up into the lower 90s for the beginning of the week with max temps beginning to dip down into the upper 80s on Tuesday for coastal areas. Overnight low temperatures will drop down into the lower to mid 70s over inland areas with min temps cooling into the upper 60s by the end of the period for inland southeast Georgia. Heat index values today will rise to over 100 for some areas during peak heating ahead of developing convection. Potential for patchy early morning fog and low cloud decks over inland areas before and around sunrise during the overnight and early morning hours this weekend. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... Main Highlights This Period: - Daily Thunderstorms Potential - Elevated Rip Current Risk Breezy onshore winds will persist through Thursday with winds becoming milder by Saturday as high pressure to the north shifts to the west and an inverted trough builds offshore to the east and presses inland, with in initially inhibited convection becoming more widespread for the end of the week. Daily high temperatures will be nearer to the seasonal average for southeast Georgia and northeast Florida Wednesday and Thursday, with max temps warming into the lower 90s by the end of the week and into the start of next weekend. Heat index values will initially be below 100 through the majority of the forecast period. && .AVIATION /06Z SUNDAY THROUGH 06Z MONDAY/... VFR conditions are noted at 06z with just debris mid to high clouds over the area. VQQ airport may tend to diminish to IFR and LIFR cig/vis through 12z, with some lighter vsby issues at JAX and GNV possible. Some of the inland terminals, including JAX, may see some MVFR ceilings of about 1000-2000 ft from about 12z-16z, and low confidence on IFR cigs. With more than sufficient moisture available, some shower activity is likely to form 12z-16z inland areas, and then spread and evolve through midday with good chance for showers and storms this afternoon. PROB30 and TEMPO groups are in place to cover the showers and storms today, with IFR to MVFR conditions expected at times. Sfc winds will be light westerly after 12z/13z at 4-8 kt, with a sea breeze developing by 18z-20z for SSI, SGJ, and CRG switching winds to the southeast. && .MARINE... Offshore winds will continue across the area waters today and on Monday, except for a sea breeze which will shift winds to the southeast and south during the afternoon hours. Another good chance of a couple of strong thunderstorms this afternoon and evening. Strong gusty winds and very heavy rainfall will accompany the stronger storms. On Monday, less thunderstorm activity is expected and likely be limited to northeast Florida nearshore waters. From Tuesday through Thursday, a strong northeast wind surge will bring small craft advisory conditions, rough seas, and numerous showers and a few thunderstorms over the area waters. 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. By Tuesday, strengthening northeast winds and building surf are expected which will continue into Thursday. This should result in a high rip current risk and dangerous surf at all area beaches during this time period. && .FIRE WEATHER... ...PATCHY TO AREAS OF HIGH DISPERSIONS TUESDAY THROUGH THURSDAY... 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 trend lower than yesterday at around 0.1 to 0.3 inches are forecast. However, model guidance still suggest some low probabilities of about 20 to 30 percent of 3 inches, mainly southeast zones. 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 92 73 94 73 / 10 10 0 0 SSI 91 77 92 79 / 20 20 0 0 JAX 92 75 93 75 / 40 20 10 0 SGJ 91 76 91 76 / 40 30 10 10 GNV 92 74 93 74 / 40 20 40 10 OCF 92 75 93 74 / 50 20 50 20 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. MARINE...None. && $$