Marine Weather and Tide Forecast for Macclenny, FL

NEAR TERM /THROUGH TONIGHT/

Main Highlights through Tonight:

A mostly sunny day is forecast for Today, with west southwest flow helping to push temperatures above average. A few showers and thunderstorms will be possible over north central FL this afternoon and evening due to diurnal instability, and convergence along the east coast sea breeze.

A cold front will move southeast across the area Tonight, with strong high pressure building behind it. A few showers will be possible across NE FL ahead of the front. Winds will increase across the area following the frontal passage. Much drier air will sweep southeast into area overnight, with dewpoints over inland SE GA falling 15 to 20 degrees. Due to the timing of the front, a broad range in low temperatures is forecast, with low 60s over inland SE GA, to the lower 70s along the NE FL coast.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/

Main Highlights This Period:

- Northerly winds expected to gust to around 40 mph at Coastal Locations, which would necessitate a wind advisory.

- Coastal hazards increase for this weekend, including Gales for marine waters, hazardous surf and rip currents, and beginning stages of elevated tidal water levels.

Following the strong cold frontal passage Saturday morning, high pressure will build north of the region driving a surge of strong northerly to northeasterly winds over the local area, especially by the afternoon. Winds expected to range up to 15 to 25 mph with gusts easily reaching 35 mph in a number of areas and localized gusts of 40+ mph which may require a wind advisory. High pressure sitting to the north and northeast will sustain these elevated winds through Sunday night, accompanied by a chance of coastal showers. An overrunning condition does setup for a time on Saturday which will support some patches of rain over southeast parts of the forecast area, but rain amounts will be very light.

Temperatures will drop significantly behind the front bringing cooler daytime highs with readings in the 70s on Saturday, and slightly warmer at the coast. Highs Sunday only mid to upper 60s for southeast GA to I-10, and then lower 70s further south.
Overnight lows for the weekend will range from the lower 50s inland over southeast GA, and upper 50s to mid 60s elsewhere, mildest in the coastal areas and north central FL. Coastal hazards escalate starting Saturday and persist through Sunday night, featuring high rip current risk and very rough surf, and elevated water levels/possible minor tidal flooding. Gale watches were posted for the marine waters starting Saturday.

LONG TERM /MONDAY THROUGH THURSDAY/
Main Highlights This Period:

- Coastal hazards including tidal flooding, gusty winds, elevated rip risk and surf expected Monday through Wednesday.

- Below normal temperatures this period.

Strong high pressure will remain anchored to the north and northeast driving a prolonged period of elevated onshore flow.
Model guidance also shows a low pressure system located well offshore near 35N72W which will be nearly stationary or drift south, and may further enhance and prolong coastal impacts mainly in terms of surf heights. For our area, this translates into continued high risk of rip currents, rough and elevated surf, and minor to moderate beach erosion along the Atlantic coast. Elevated water levels anticipated along the coast, Intracoastal Waterway, and the St Johns River basin mainly in the minor category. Wind will remain breezy to windy, with sustained winds of 15-25 mph with gusts reaching 35-40 mph along the coast. Winds will begin to taper off by midweek as the high pressure begins to weaken.

Rain chances will be isolated to scattered range or about 15-25 percent for northeast FL coast but may reach as far as Highway 301 at times. Drier conditions expected further inland over northeast FL and for southeast GA.

Temperatures will be below average during the period, with daytime highs around the lower to mid 70s Monday, trending to the mid to upper 70s mid week. Overnight lows will generally be in the lower to mid 50s inland, then upper 50s to lower 60s coast for Monday, and trending very gradually warmer into mid week as the low level flow slowly veers bringing in more modified air off the Atlantic.

AVIATION /12Z FRIDAY THROUGH 12Z SATURDAY/

VFR conditions will prevail at the regional terminals through at least 09Z Saturday. MVFR ceilings of 1,500 - 2,000 feet will then overspread the terminals from north to south after 09Z, with isolated to widely scattered showers possible towards the end of this TAF period. Confidence in timing of shower development during the predawn and early morning hours on Saturday is currently too low to introduce vicinity shower coverage at this time. Light surface winds this morning will generally become west-southwesterly at 5-10 knots after 18Z at the inland terminals, while the Atlantic sea breeze moves inland early this afternoon, shifting surface winds to east or southeasterly around 10 knots at the SGJ and SSI coastal terminals by 18Z. Surface winds will then shift to southwesterly after 02Z as speeds gradually diminish. Surface winds will then abruptly shift to northwesterly while increasing to 10-15 knots and gusty before 12Z Saturday, accompanying the arrival of MVFR ceilings.

MARINE

High pressure ridge over area will weaken Today, as a strong cold front approaches from the northwest. This front will move southeast across the area Tonight, with strong high pressure building behind it. A period of elevated winds and building seas will be expected from Saturday through much of next week, with gales likely beginning on Saturday and possibly continuing into Monday night.

Rip Currents: Low to Moderate risk Today. High risk of rip currents with rough surf from Saturday through much of next week.

FIRE WEATHER

- PATCHY HIGH AFTERNOON DISPERSIONS TODAY OVER INLAND SOUTHEAST GA.
- AREAS OF HIGH DISPERSION VALUES THIS WEEKEND.
- ELEVATED NIGHTTIME DISPERSION ALONG THE COAST SATURDAY NIGHT AND SUNDAY NIGHT.

Southwest to west winds develop today ahead of an approaching cold front. The cold front will push through the area tonight.
Moderate to strong north to northeast winds develop this weekend behind the cold front as high pressure builds north of the area. Elevated winds are expected along the Atlantic coast of SE GA and NE FL beginning late tonight, with the elevated winds persisting into the upcoming week. This will bring chances of showers for coastal locations through the weekend and next week.

For today, Good to High dispersions develop over SE GA ahead of the frontal boundary, with Fair to good dispersions expected over NE FL.

HYDROLOGY

Minor flooding will continue along lower portions of the Satilla River during the next several days.

TIDES/COASTAL FLOODING

Minor tidal flooding is possible along the Atlantic coast, ICWW, and St. Johns river basin this weekend and early next week as strong northeasterly winds develop. Some significant beach erosion is possible by Sunday, especially coastal northeast FL, as seas for the nearshore waters build to the 10-15 ft range through Monday night while southeast GA nearshore seas mainly in the 8-13 ft range.

PRELIMINARY POINT TEMPS/POPS
AMG 86 61 70 50 / 0 10 10 0 SSI 86 67 74 58 / 0 20 20 0 JAX 88 68 74 57 / 0 20 20 0 SGJ 87 70 76 64 / 10 20 30 10 GNV 89 69 75 57 / 10 20 20 0 OCF 89 71 76 59 / 30 20 30 10

JAX WATCHES/WARNINGS/ADVISORIES
FL...None.
GA...None.
MARINE...Gale Watch from Saturday morning through late Monday night for AMZ450-452-454-470-472-474.