807 FXUS62 KJAX 060816 AFDJAXArea Forecast Discussion National Weather Service Jacksonville FL 416 AM EDT Mon Oct 6 2025
...New SYNOPSIS, NEAR TERM, SHORT TERM, LONG TERM, MARINE, HYDROLOGY...
.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
- Minor to Moderate Tidal Flooding Continues this Week and into the Upcoming Weekend. A Coastal Flood Warning for Moderate Tidal Flood Impacts Continues within the St. Johns River Basin to the South of Downtown Jacksonville.
- Dangerous Beach & Marine Conditions through Tuesday, Returning Late this Week and Next Weekend. High Rip Current Risk, High Surf & Small Craft Advisories remain posted through Tuesday.
- Locally Heavy Rainfall & Localized Flood Risk Today, with Isolated Thunderstorms Possible.
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.SYNOPSIS... Issued at 416 AM EDT Mon Oct 6 2025
Early morning surface analysis depicts persistent high pressure (1027 millibars) stretching from the Mid-Atlantic coast to offshore of coastal New England. This feature continues to wedge down the southeastern seaboard, with coastal troughing remaining positioned over our near shore Atlantic waters. Meanwhile, weak low pressure centers were embedded along a remnant frontal boundary near southeast FL and coastal Louisiana. Otherwise, a cold front was pushing east southeastward from the western Great Lakes and Upper Midwest through the Plains states. Aloft...ridging centered along the Carolina coast continues to build over our region, with the axis of this feature extending southward into the southeast Gulf. Previously cutoff troughing along the northern Gulf coast was shearing out as a longwave trough digs southeastward from the Rockies and the northern Plains towards the Upper Midwest.
Latest GOES-East derived Total Precipitable Water imagery indicates PWATs remain above early October climatology throughout our region, with values mostly in the 1.75 - 2 inch range. Values in excess of 2 inches prevail along the Interstate 4 corridor in central FL. Coastal troughing was currently only generating isolated showers over the Atlantic coastal waters, with land areas remaining dry during the predawn hours. Marine stratocumulus continues to occasionally move onshore and across the I-95 corridor in northeast FL, while lower stratus clouds were developing beneath higher altitude cirroform clouds across inland portions of southeast GA. Temperatures at 08Z ranged from around 70 across inland portions of southeast GA and the Suwannee Valley to the upper 70s at coastal locations. Dewpoints ranged from the mid 60s across inland portions of southeast GA and northern portions of the Suwannee Valley to the mid 70s at coastal locations.
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.NEAR TERM... (Today and Tonight) Issued at 416 AM EDT Mon Oct 6 2025
Our stagnant weather pattern continues today, featuring brisk easterly low level flow, compliments of a stubborn surface ridge wedging down the southeastern seaboard, and persistent coastal troughing over our near shore Atlantic waters. This trough and strengthening low level convergence will likely create an increasing coverage of showers and possibly a few embedded thunderstorms over the Atlantic waters towards sunrise that will quickly move onshore after sunrise, mainly along the northeast FL coast. Deeper moisture currently in place along the I-4 corridor in central FL will advect northward this morning, and we expect numerous showers and a few embedded thunderstorms along the I-95 corridor by the mid to late morning hours. This activity will shift inland across the U.S. Highway 301 and Interstate 75 corridors, with activity remaining more scattered in nature across southeast GA, where PWAT values should remain below 2 inches today. Embedded thunderstorms developing today will be capable of producing torrential downpours given the tropical moisture that will be overspreading north central and northeast FL, with brief wind gusts of 30-40 mph also possible.
Morning stratus developing across inland southeast GA and portions of the Suwannee Valley will lift by the mid-morning hours, with peaks of sunshine later this morning boosting highs to the mid and upper 80s for locations west of U.S.-301. Showers and thunderstorms developing before noon and brisk onshore winds will keep highs in the low to mid 80s for areas east of U.S.-301.
A few additional bands of showers will continue to advect onshore early this evening along the Atlantic coastal counties as brisk onshore flow persists. However, deeper convection developing today is expected to shift west of the Suwannee and Alapaha Rivers towards sunset, and a pocket of drier air, featuring PWATs of less than 1.5 inches, will advect across most of southeast GA after midnight. PWATs elsewhere will fall back to the 1.75 - 2 inch range overnight, allowing for a decreasing coverage of showers by the predawn hours on Tuesday. Another round of low stratus clouds and possibly some fog may develop within the drier and more subsident air mass that will be advecting across inland portions of southeast GA during the predawn and early morning hours on Tuesday. Lows tonight will again range from the upper 60 / around 70 for inland southeast GA and the Suwannee Valley to the mid 70s at coastal locations.
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.SHORT TERM... (Tuesday through Wednesday night) Issued at 416 AM EDT Mon Oct 6 2025
Tuesday, drier air moving into the area will have precipitation chances trend down as high pressure over the mid-Atlantic states shifts towards the Atlantic ahead of an approaching cold front. Continued easterly onshore flow and lingering moisture will bring isolated to scattered showers push in from the local waters towards coastal locations during the morning hours. By the afternoon, showers will push towards inland locations, with a stray storm possible. Daytime highs will in the 80s with warmer temps away from the coast. Overnight lows in the upper 60s over inland SE GA and from the Suwannee Valley Region towards the US-301 corridor of NE FL, lower 70s along the coast and north central FL counties.
Wednesday, dry air continues to build over the area into midweek as most of the area will be shower-free aside for chances of isolated showers along Flagler, Putnam, St. Johns and southern Marion counties during the afternoon hours. Otherwise, highs will once again be in the 80s area-wide and a bit warmer than Tuesday as cloud cover will be lower than Tuesday. The cold front will begin to cross into northern SE GA by Wednesday Night, where some showers may development during the overnight hours along the Altamaha River Basin. Overnight lows similar to Tuesday Night.
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.LONG TERM... (Thursday through Sunday) Issued at 416 AM EDT Mon Oct 6 2025
A cold front will shift south across the area through Thursday and clear south of the area by Friday while an area of low pressure will begin to lift north-northeast over the western Atlantic waters. With this pattern, elevated northeast onshore flow will likely develop with winds in the 25 to 30 mph range over the local waters and coastal locations. As this will still coincide with the Full Moon and higher tides, the onshore northeasterly flow will likely continue the risk of coastal hazards of rip currents, coastal flooding, dangerous maritime boating conditions, and rough surf during the later half of the upcoming week into the weekend. Otherwise, scattered chances of precipitation on Thursday into Friday as showers push onshore with the northeast flow. By Saturday, chances of precipitation begin to trend downward again as guidance suggests the area of low pressure shifts east- northeast towards the Atlantic.
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.AVIATION... (06Z TAFS) Issued at 208 AM EDT Mon Oct 6 2025
Periods of MVFR ceilings between 2,000 - 3,000 feet will remain possible at the regional terminals through around 09Z. Lower stratus ceilings may develop after 07Z at GNV and VQQ, but confidence was too low to indicate IFR conditions in the TAFs at this time. Showers are expected to increase in coverage and intensity across our local Atlantic waters during the predawn hours, with this activity then moving onshore and impacting the SGJ terminals just before sunrise, with activity then progressing westward across the Duval County terminals during the early morning hours. Confidence in this scenario was high enough to include TEMPO groups for brief wind gusts up to 25 knots and IFR visibilities during heavier downpours. Embedded thunderstorms will be possible within these heavier showers, but confidence was too low to include vicinity thunderstorm coverage during the early morning hours. Activity may extend northward to the SSI terminal, but confidence in impacts was only high enough to include a PROB30 group after 10Z. Additional showers and thunderstorms are then expected to develop during the morning and early afternoon hours at the SGJ and Duval County terminals, and PROB30 groups for thunderstorm impacts featuring wind gusts up to 30 knots and IFR visibilities during heavier downpours were used into the afternoon hours. Activity will progress westward towards the GNV terminal after 16Z, where confidence was high enough to include vicinity thunderstorm coverage and a PROB30 group through around 23Z. Showers and thunderstorms should then shift west of the regional terminals after 00Z, with VFR conditions expected to prevail on Monday evening. Easterly surface winds will remain sustained around 10 knots overnight at SGJ, while northeasterly winds remain sustained at 5 knots or less. Easterly winds will then increase to around 15 knots and gusty at SGJ before 14Z, with speeds elsewhere increasing to 10-15 knots and gusty before 17Z.
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.MARINE... Issued at 416 AM EDT Mon Oct 6 2025
High pressure centered along the Mid-Atlantic coast will continue to wedge down the southeastern seaboard, while coastal troughing remains situated over our near shore waters through Tuesday. Gusty easterly winds and Small Craft Advisory conditions featuring rough, elevated seas will continue across our local waters through at least tonight. Seas of 5-8 feet will prevail through tonight near shore, while seas offshore of 7-9 feet are forecast. Meanwhile, waves of showers and a few embedded thunderstorms will continue to traverse our area through Tuesday. High pressure will then shift further offshore of the Mid-Atlantic coast by Tuesday night and Wednesday, allowing coastal troughing to weaken over our local waters. Winds and seas will briefly diminish below Caution levels near shore and to Caution levels for the offshore waters adjacent to northeast FL. A cold front entering the southeastern states on Wednesday will then shift slowly southward across our local waters by Thursday and Thursday night. Strong high pressure building over New England will wedge down the southeastern seaboard late this week as low pressure potentially develops over the Gulf Stream waters adjacent to southeast Florida. Northeasterly winds will quickly strengthen on Thursday, with Small Craft Advisory conditions expected to extend throughout our local waters into next weekend as onshore winds potentially gust to Gale Force.
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.HYDROLOGY... Issued at 416 AM EDT Mon Oct 6 2025
Water levels have remained at minor flood thresholds during times of high tide at most gauges along the Atlantic coast and the Intracoastal Waterway (ICCW) in Duval, St. Johns, and Flagler Counties since Sunday, as well as along the St. Johns River and its tributaries in Duval County. We have thus lowered the Coastal Flood Warning for these locations and have issued a Coastal Flood Advisory through midweek, as minor flooding is expected to continue during times of high tide, with water levels generally reaching 1.5 to 2 feet above Mean Higher High Water (MHHW) during times of high tide. Coastal Flood Warnings remain in effect within the St. Johns River basin to the south of downtown Jacksonville, where water levels will continue to reach moderate flood thresholds (generally around 2 feet above MHHW) during times of high tide during the next several days.
As onshore winds gradually diminish towards midweek, astronomical influences from this week`s full "Hunter`s" moon will continue to increase, setting up a potentially significant coastal and tidal flood event later this week and into the upcoming weekend as a surge of strong northeasterly winds potentially overspreads our area. Coastal Flood Warnings and Advisories will likely be expanded by Thursday and Friday all along the Atlantic coast and throughout the St. Johns River basin.
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.PRELIMINARY POINT TEMPS/POPS... AMG 86 69 87 67 / 30 10 10 0 SSI 82 73 83 73 / 30 10 20 0 JAX 83 73 86 70 / 50 10 30 0 SGJ 83 76 85 73 / 60 20 30 10 GNV 86 73 90 68 / 60 20 30 0 OCF 85 73 88 70 / 60 20 30 0
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.JAX WATCHES/WARNINGS/ADVISORIES... FL...Coastal Flood Advisory until 5 AM EDT Wednesday for FLZ124-125- 138-225-233-325-333.
High Rip Current Risk through late Tuesday night for FLZ124-125- 138-233-333.
Coastal Flood Warning until 5 AM EDT Wednesday for FLZ132-137- 633.
High Surf Advisory until 5 AM EDT Tuesday for FLZ138-233-333.
GA...Coastal Flood Advisory until 5 AM EDT Wednesday for GAZ166.
High Rip Current Risk through late tonight for GAZ154-166.
AM...Small Craft Advisory until 10 AM EDT Tuesday for AMZ450.
Small Craft Advisory until 5 AM EDT Wednesday for AMZ452-454-472- 474.
Small Craft Advisory until 5 PM EDT Tuesday for AMZ470.
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NWS JAX Office Area Forecast Discussion