Marine Weather and Tide Forecast for Fernandina Beach, FL

NEAR TERM /THROUGH TONIGHT/
WEATHER CONCERNS THROUGH TONIGHT:

- Areas of dense fog expected early to mid morning, especially over southeast GA and the St. Johns River Basin

Fog and low clouds are much slower to develop early this morning as compared to Wednesday Morning, though expected to pick up over the next several hours and persist through about mid morning for most of the area. With flow starting to establish itself as more southeasterly rather than easterly, confidence in areas of fog decreases rather quickly for areas further south and west, such as for cities like Ocala and Gainesville and for areas generally along the I-75 corridor south of I-10. That being said, still anticipating at least areas of dense fog over parts of the St.
Johns River Basin and southeast GA, likely becoming more patchy the further south and west you go.

Fog and low clouds dissipate around mid morning, with another very mild day for many with a southeasterly flow. The increase in low level moisture that has built up over the past few days will also bring chances for convective showers further inland during the afternoon and evening as the Atlantic sea breeze pushes inland.
Highest chances for a few showers will be generally towards I-75 in FL, though a few showers will be possible as far north as western inland GA counties. Though enough moisture will be in place for some convective showers, the combination of PWATs only around the 1.2 to 1.4 in range and minimal instability will result in very low chances for any thunder. Above normal temps continue for the vast majority of the area, with low to mid 80s common inland and only in the mid to upper 70s closer to the immediate coast.

Tonight will feature mild lows a few degrees warmer than Thursday Morning, with chances for fog returning for much of the area as well. Short term guidance is rather split and generally not as aggressive with fog potential over the area at this time, however still expecting at least patchy fog to return for most of the area, becoming locally dense at times in some spots. Min temps in the low to mid 60s will be common.

SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/
Main Highlights Fri-Sat:

- Nightly fog and stretches of sea fog lasting through the morning.
- Few to Scattered inland showers daily; isolated t'storm Friday afternoon - Warming Trend, approaching records each day

Warming southeasterly flow will lead to days of near record highs and even record high minimum temperatures under the influence of an upper ridge that'll be sliding eastward further into the Atlantic through the period. The strong temperature gradient between the inland heat and the cool shelf waters will drive a modestly strong sea breeze inland each day. Increasing southerly flow will bring some mid level moisture back into the mid levels on Friday which combined with the diurnal heating and surface moisture may lead to an isolated thunderstorm during the late afternoon along the I-75 corridor. With thunder probs (10-20%), confidence still isn't there to mention any extensive area where thunderstorms are possible Friday.

Upper ridge will begin to break down and shift east on Saturday as the flow aloft trends broadly more cyclonic. Overall, similar expectations are expected on Saturday with less of threat for isolated PM storms as drier air moves back into the mid levels.

The already moist boundary layer, amplified by the daily sea breeze pushes, will set up each night for fog development. Radiative fog and an advective fog from the coastal waters will be possible each night. At a minimum, locally dense fog is expected each morning.

Inland temperatures will challenge daily records this period as highs climb to the upper 80s. The beaches and coastal zones will stay about 5-10 degrees cooler due to the prevailing onshore flow.
Lows will be quite mild as well, also challenging records, with minimum temps in the low/mid 60s.

LONG TERM /SUNDAY THROUGH WEDNESDAY/
Main Weather Highlights Sun-Thur:

- Near record high temperatures for inland areas - Nightly Fog Potential Continues - Increasing chance for thunderstorms late next week - Elevated rip current risk amid persistent onshore flow and swells

Pattern shift continues Sunday into Monday as westerly flow aloft envelopes the region. This will halt an approaching front, stalling it to the northwest while a locally persistent southeasterly flow prevails, pushing the east coast sea breeze well inland each day through Tuesday. Diurnal instability will be marginal each day during this stretch, but sufficient low level moisture appears to be in place to support a slight chances of showers along the sea breeze as it moves inland each afternoon. Medium range guidance is honing in on the next upper trough and attendant cold front reaching the region Thursday bringing a line of showers and thunderstorms. While this may bring a needed rainfall, the drought-stricken vegetation may be susceptible to lightning ignitions. Above normal temperatures at inland locations will continue and make a push toward the 90 degree mark each day. The potential for nightly bouts of radiative fog continues during this period with little change in the boundary layer moisture.

AVIATION /12Z THURSDAY THROUGH 12Z FRIDAY/

A mixed bag of ceilings this morning. Developing southeasterly winds have begun to mix thin low stratus as of 11z and is likely to erode it completely by 13z or sooner. Shallow fog may develop briefly but it isn't expected to persist at area airfields. VFR conditions are favored through the afternoon and early evening. The only concern with the forecast after 00z is the formation and potential inland movement of any sea fog. Trended cloud bases to account for the uncertainty at coastal airfields between 00z-06z. Beyond 06z, high probability of LIFR exists for coastal terminals along the I-95 corridor, around 50-80% probability. Winds will be breezy from the ESE and trend E with the sea breeze this afternoon with gusts up to 15 knots with the sea breeze as it passes.

MARINE

Dense sea fog at times will lead to difficult navigation conditions across the waters through the rest of the week, especially during overnight periods. There will be periods over the next few days where fog lifts to stratus, but prevailing visibilities will generally be low, especially within about 20 to 30nm from the coast.
Sea fog is likely to continue through the weekend as warm, moist air is pushed across the water by southeasterly flow. Otherwise, surface high pressure will remain fairly stationary, near Bermuda, throughout the next week.

Rip Currents: Breezy onshore winds shift more east to southeasterly today, with breakers of 3-4 feet at the northeast FL beaches and 2-3 feet at the southeast GA beaches. Rip current risk will be high over northeast FL beaches today along the St. Johns and Flagler County coastlines, and higher end moderate for the rest of area beaches. A similar trends is likely to continue through Friday as well. An elevated rip current risk will continue through the weekend and into early next week at area beaches as persistent southeasterly winds prevail.

FIRE WEATHER

Temperatures will trend warmer through the weekend, near record levels for early March, through the weekend under the influence of a dominant upper ridge. A prolonged, moist southeasterly flow will bolster the Atlantic sea breeze each afternoon and widely scattered showers are possible along the sea breeze, especially Friday afternoon, with the best chances along the I-75 corridor. The moist airmass will carry the potential for nightly fog, which may become locally dense. Fair to good afternoon dispersion and favorable humidity trends will persist through the weekend. Pattern shift next week with a frontal system possible Wednesday/Thursday.

FOG POTENTIAL AND OTHER REMARKS: Areas of fog may become locally dense each night. Moderate sea breeze is expected with easterly winds 10-15 mph pushing it across the region for the next several afternoons.

CLIMATE
Record High Temperatures:

March 5: KGNV: 87/1997

March 6: KGNV: 87/2023 KAMG: 86/1961

March 7: KGNV: 88/2023 KAMG: 86/1956

March 8: KJAX: 88/1945 KGNV: 88/1921 KAMG: 86/1974 KCRG: 86/1998

March 9: KJAX: 88/2024 KGNV: 89/1907 KAMG: 88/1974

March 10: KGNV: 90/1974 KAMG: 88/1974 KCRG: 86/2019

Record High Minimum Temperatures:

March 7: KGNV: 66/1935

March 8: KGNV: 65/1973

PRELIMINARY POINT TEMPS/POPS
AMG 82 61 84 61 / 10 10 20 10 SSI 73 60 73 61 / 10 10 10 10 JAX 83 61 84 61 / 10 0 20 0 SGJ 78 62 79 62 / 10 10 20 10 GNV 86 62 88 62 / 20 10 30 10 OCF 87 63 88 63 / 30 30 30 10

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