Area Forecast Discussion
Issued by NWS Jacksonville, FL
Issued by NWS Jacksonville, FL
646 FXUS62 KJAX 190554 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 154 AM EDT Sun Jul 19 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 - Thunderstorm chances and coverage will increase today through Tuesday as tropical moisture overspreads the region. Localized Flooding will be the primary Thunderstorm Hazard. - Likely (60% Chance) Development of Invest 91 into a weak tropical disturbance over eastern Gulf of America over the next 48 hours. - Moderate Rip Current Risk today and Monday, possibly High Risk Tuesday. && .NEAR TERM /THROUGH TONIGHT/... Main Highlights Today and Tonight: - Scattered afternoon and early evening thunderstorms mainly across NE FL today. - Invest 91 is forecast to gradually drift north and then west while it continues to organize. NHC now has increased probability to 60% for development through Monday. The gradual organization of surface circulation has continued early this morning beneath the upper low in the northeastern Gulf. Showers and isolated thunderstorms rotating around the eastern side of the disturbance have been tracking south to north across central FL and pushing into the north-central FL zones. This nocturnal convection will lose support as it lifts north of I-4 and into our area through the predawn hours, but cannot entirely rule out an isolated thunderstorm making it to Marion or Putnam county. For Today...the focus and primary weather feature will be the gradual development and deepening of the Invest 91 disturbance. Dry air circulating around the system will advect northward this morning along the FL peninsula and initially capping early afternoon convection for zones along the I-95 corridor in NE FL and much of SE GA. Behind the dry air, deeper moisture will quickly overspread the area, fueling scattered thunderstorms later this afternoon as convergence along the east coast sea breeze enhances amid the southeasterly flow. The best chances for strong thunderstorms will be focused along and west the St Johns River basin. Cloudier skies and scattered showers will keep highs a bit lower than normal for portions of NE FL along the I-75 corridor this afternoon with highs in the upper 80s to near 90. While areas west will be about 3-7 degrees warmer, generally in the low to mid 90s which will result in peak heat index around 100-105 during the hottest part of the day. Tonight...Invest 91 is progged to drift slightly north and west. It`s possible that the rain bands around the circulation will lift across the Big Bend and through the Suwannee Valley overnight bring an additional round or two of needed rainfall in those areas. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... Main Highlights This Period: - Bouts of Showers and Storms & Heavy Rainfall, Especially for Western Areas Focus still remains on if there will be any further development of the broad surface Low currently located along the eastern Gulf. Current model guidance continues to show a north-northwest shift of the Low, with the Low being positioned south of the FL panhandle on Monday, and then begins a shift northward towards the Gulf coast sometime late Monday to early Tuesday. The western locations of the area still are expected to have the highest chances of precipitation at the start of the upcoming week with showers and storms associated with the Low sweep along the FL peninsula. The influence of the Low will result in the overall flow to be from the south-southeast, allowing for an inland push of the Atlantic sea breeze each afternoon, with showers and storms developing as it pushes towards inland locations. While we expect for temperature to rise into the low 90s, cloud cover and passing showers could bring cooler temperatures for some locations. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... Main Highlights This Period: - Scattered to Numerous Afternoon Thunderstorms - Potential heat advisory conditions by the middle of next week Ridging will begin to build over the FL peninsula by midweek as the Gulf Low is expected to continue to weaken. Scattered chances of precipitation area-wide on Wednesday. An approaching frontal boundary will likely bring higher chances of precipitation across SE GA as the boundary begins to stall nears the region during the later part of the upcoming week. Temperatures will be in the low to mid 90s during the afternoon hours through the upcoming week and into the weekend. && .AVIATION /06Z SUNDAY THROUGH 06Z MONDAY/... A few light showers will drift south to north along the I-75 terminal through the early morning hours but VFR conditions are expected to continue. Showers should generally stay west of the NE FL terminals along the I-95 corridor during the predawn hours. Breezy south to south-southeastelry winds around 8-12 knots will develop ahead of the sea breeze this morning and early afternoon. The sea breeze will push into the coastal terminals around 17-19z, shifting winds to the ESE with gusts around 15 knots. As moisture overspreads the area, there will be increasing chances for convection during the late afternoon hours. TSRA chances will higher but for NE FL terminals but rogue SHRA cannot be ruled out this evening at KSSI. Convective activity will generally diminish after 00z. && .MARINE... The potential tropical disturbance organizing in the northeastern Gulf of America will strengthen slightly today. As it does, southerly winds will strengthen across the local waters to Exercise Caution levels this afternoon. Though the Invest 91 low pressure should move northwest, it`s influence will continue breezy southerly winds through at least Wednesday. As high pressure to the east strengthens, winds may strengthen near Small Craft Advisory levels causing seas to elevate on Tuesday. For the second half of the week, offshore flow will develop as a cold front approaches front he northwest and stalls just north of the waters next weekend. Rip Currents: Breezy longshore flow will keep breakers around 2-3 feet and result in a solid Moderate Risk of rip currents this afternoon as the sea breeze pushes onshore. A period of stronger southerly winds is expected Monday and Tuesday which will elevate breakers to 3-5 feet. Right now, Monday the risk will be kept at Moderate. As surf builds Tuesday, risk will likely jump to the High Risk for rip currents. && .FIRE WEATHER... An increase in moisture and southerly winds is expected over the next several days as an upper level low spins in the eastern Gulf, slowly drifting north and west through early next week. The National Hurricane Center gives this low a 60% chance of developing tropical characteristics over the next 48 hours, though impacts to our area area expected to be limited outside of bands of showers and thunderstorms affecting the area at times during daytime heating. Otherwise, the increase in flow will result in good dispersions for most, with the main exceptions being near the immediate coast and west of about I-75 in northeast FL where dispersions will be slightly lower thanks to more cloud cover. The low weakens by mid next week, with a frontal boundary dropping southward towards the region. 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 94 74 93 74 / 20 10 50 10 SSI 93 80 92 80 / 10 10 40 20 JAX 94 77 93 77 / 20 10 50 10 SGJ 92 77 92 77 / 20 10 50 20 GNV 92 74 91 74 / 30 30 60 20 OCF 91 75 91 75 / 40 40 60 10 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. MARINE...None. && $$