Marine Weather and Tide Forecast for Green Cove Springs, FL

SYNOPSIS
Issued at 337 PM EDT Thu Oct 3 2024

Afternoon surface analysis depicts high pressure (1022 millibars)
centered over New England and the Mid-Atlantic states, with this feature wedging down the southeastern seaboard. A weak coastal trough has developed over the the near shore Atlantic waters adjacent to coastal southeast GA and northeast FL, and this feature was generating isolated to widely scattered showers that were advecting onshore along the southeast GA coast. An earlier shower that moved onshore along Vilano Beach in coastal St. Johns County contained a waterspout
Aloft
ridging was in place along the southeastern seaboard and extended southward through the Bahamas and the Greater Antilles. Latest GOES-East derived Total Precipitable Water imagery indicates that a seasonably dry air mass remains in place for inland locations along and north of the Interstate 10 corridor, where PWATS were around 1.25 inches. A tighter moisture gradient was in place across north central FL and the Suwannee Valley, with values increasing to around 1.75 inches for locations west of the I-75 corridor. Meanwhile, breezy and convergent low level onshore flow was advecting slightly higher moisture levels around 1.5 inches towards coastal locations from the Atlantic waters. Marine stratocumulus continues to increase along the southeast GA coast, where temperatures at 19Z were only around 80 degrees, while a flatter cumulus field elsewhere allowing temperatures to climb to the mid and upper 80s. Dewpoints ranged from the mid and upper 60s across inland southeast GA to the low and mid 70s at coastal locations.

NEAR TERM
(through Tonight)
Issued at 337 PM EDT Thu Oct 3 2024

Coastal troughing will continue to focus occasional shower activity over coastal southeast GA, with some potential for a round of brief showers advecting onshore along the northeast FL coastal counties during the overnight and early morning hours. An isolated thunderstorm cannot be ruled out, mainly for coastal locations. Marine stratocumulus should gradually increase overnight along the I-95 corridor and inland southeast GA, which should limit the potential for fog formation. Patchy fog will be possible for locations along and west of U.S. Highway 301 in northeast and north central FL during the predawn hours as winds decouple and only high altitude cloud cover is expected. Lows tonight will range from the upper 60s for inland locations north of Waycross to the lower 70s elsewhere inland. An onshore breeze will keep coastal lows generally in the upper 70s.

SHORT TERM
(Friday through Saturday night)
Issued at 337 PM EDT Thu Oct 3 2024

Friday, moisture increases as low level onshore flow veers around to the southwest as mid/upper level ridging migrates south from the Carolina coast towards the northern Bahamas by late in the day.
Weak inverted troughing will push scattered Atlantic coastal showers onshore in the morning and midday hours with isolated T'storms inland in the afternoon as the easterly flow pushes the Atlantic seabreeze well inland. Clouds will increase with the increased moisture and along with onshore winds from the ENE, highs will be in the mid 80s over SE GA, upper 80s along and south of I-10.

Saturday will be similar with inverted troughing over the local waters helping to keep coastal showers moving onshore early in the day and shifting inland with a low chance for T'storms. Highs will be a notch cooler compared to Friday with near normal values in the mid 80s and upper 80s over north central FL. Lows will begin the day in the low 70s over the interior portions of SE GA and NE FL with mid to upper 70s along the coast.

LONG TERM
(Sunday through next Thursday)
Issued at 337 PM EDT Thu Oct 3 2024

Elevated east to northeasterly winds will persist with increasing showers Sunday into early next week and a cold front sinks south into the area and stalls while a broad low develops over the Gulf of Mexico. NHC probability of development is 30% for the system to become tropical this weekend into early next week. Locally heavy rainfall may occur over northeast Florida into the SE GA coast from a combination of tropical moisture lifting from the east side of the broad low and strong northeasterly flow as a series of cold fronts approach and stall over the area. Continue to monitor the forecast for updates on the genesis of the low and potential heavy rainfall impacts over the area next week.

Highs will be a bit cooler than average in the lower 80s during the period due to cool, breezy onshore ENE winds and mostly cloudy conditions. Lows will begin above normal and then trend to near normal next week with below normal lows sneaking into portions of SE GA by midweek.

AVIATION
(00Z TAFS)
Issued at 750 PM EDT Thu Oct 3 2024

Winds will back to the northeast tonight as the existing coastal trough slowly slides westward. This same trough will generate showers that will advect into the coastal sites through the evening.
Waves of heavier showers are possible at airfields along the immediate coast (KSSI/KSGJ), degrading visibility to IFR levels at times. Outside of shower influence and at inland sites, VFR conditions are forecasted through the night with ceilings falling to MVFR as a stratocumulus deck builds and shifts inland.

Mainly anticipate showers coverage to expand along the coast in the morning hours Friday and shift inland (westward) through the early afternoon. Winds will trend easterly Friday and become occasionally gusty, perhaps a bit more frequent at the airfields along the coast.
Gusts generally in the 15-20 knot range.



MARINE
Issued at 337 PM EDT Thu Oct 3 2024

High pressure building over New England will wedge down the southeastern seaboard through the weekend, resulting in breezy east northeasterly winds and gradually building seas across our local waters. Small Craft should Exercise Caution if venturing into the offshore waters, where speeds will increase to 15-20 knots and seas will build to 5-6 feet. Seas near shore will remain in the 4-5 foot range through the weekend. A weak coastal trough situated over the near shore waters will produce periodic waves of showers and a few embedded thunderstorms through the weekend.
Meanwhile, a broad low pressure will develop over the southern and central portions of the Gulf of Mexico by Saturday night, resulting in increasing coverage of showers and thunderstorms early next week. Winds and seas are forecast to reach Caution levels near shore and Small Craft Advisory levels for the offshore waters beginning on Monday, with these conditions then expanding to the near shore waters towards Tuesday.

Rip Currents: Breezy onshore winds will combine with a long period northeasterly swell to produce a moderate to high risk of rip currents at area beaches on Friday. Gradually building and increasingly rough surf conditions are expected as breezy onshore winds continue this weekend, likely creating a high risk at all area beaches. An even longer period swell originating from distant Major Hurricane Kirk will arrive at our beaches early next week, resulting in dangerous and life threatening surf conditions.

HYDROLOGY
Issued at 337 PM EDT Thu Oct 3 2024

A flood wave is traveling downstream along the Alapaha River, with water levels forecast to rise to flood stage near the gauge at Statenville on Friday evening. Moderate flooding is forecast at the Statenville gauge towards midnight on Friday night, with a crest near major flood levels possible by Sunday afternoon.
Otherwise, water levels are cresting along upper portions of the Altamaha River near the gauges at Charlotteville and Baxley, where minor flooding will continue during the next several days. Water levels will continue to rise along middle and lower portions of the Altamaha River, with minor flooding ongoing near the gauge at Doctortown, where a crest is expected late on Friday. Water levels will quickly rise near the gauge at Everett City on Friday, reaching flood stage by Saturday afternoon and then cresting near or just below moderate flood levels late this weekend. Water levels will also rise along lower portions of the Suwannee River next week, with minor flooding forecast for portions of the river from around the gauge at Luraville southward. This flood wave will create backwater flooding near the confluence with the lower Santa Fe River beginning late this weekend, causing minor flooding to begin near the gauge at Three Rivers Estates beginning on Sunday afternoon.

PRELIMINARY POINT TEMPS/POPS
AMG 87 69 85 70 / 10 10 30 10 SSI 85 77 84 78 / 20 40 40 30 JAX 88 72 87 72 / 10 30 50 20 SGJ 87 77 86 77 / 10 40 50 20 GNV 91 71 89 73 / 10 10 50 20 OCF 91 72 91 72 / 20 10 40 20

JAX WATCHES/WARNINGS/ADVISORIES
FL...None.
GA...None.
AM...None.