Marine Weather Net

Altamaha Sound to Fernandina Beach FL Marine Forecast


TONIGHT

E
WINDS
5 - 10
KNOTS

WEDNESDAY

SE
WINDS
5 - 10
KNOTS

WEDNESDAY NIGHT

SE
WINDS
5 - 10
KNOTS

THURSDAY

SW
WINDS
5 - 10
KNOTS

The Marine Weather Forecast In Detail:
AMZ450 Forecast Issued: 809 PM EST Tue Jan 18 2022

Tonight...East Winds 5 To 10 Knots. Seas 1 To 2 Feet With A Dominant Period 11 Seconds. Mostly Smooth On The Intracoastal Waters.
Wednesday...Southeast Winds 5 To 10 Knots. Seas 1 To 2 Feet With A Dominant Period 10 Seconds. A Light Chop On The Intracoastal Waters.
Wednesday Night...Southeast Winds 5 To 10 Knots Becoming Southwest After Midnight. Seas 1 To 2 Feet With A Dominant Period 3 Seconds. Mostly Smooth On The Intracoastal Waters.
Thursday...Southwest Winds 5 To 10 Knots. Seas 1 To 2 Feet. A Light Chop On The Intracoastal Waters.
Thursday Night...Southwest Winds 5 To 10 Knots Becoming Northwest After Midnight. Seas 1 To 2 Feet. Mostly Smooth On The Intracoastal Waters. Chance Of Showers.
Friday...North Winds 10 To 15 Knots Increasing To 15 To 20 Knots In The Afternoon. Seas 2 To 3 Feet. Choppy On The Intracoastal Waters. Chance Of Showers.
Friday Night...North Winds 15 To 20 Knots. Seas 3 To 4 Feet. Chance Of Showers.
Saturday...North Winds 15 To 20 Knots. Seas 4 To 6 Feet. Chance Of Showers.
Saturday Night...North Winds 10 To 15 Knots. Seas 4 To 6 Feet. Chance Of Showers.
Sunday...Northwest Winds 10 To 15 Knots. Seas 4 To 6 Feet.
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AMZ400: Synopsis for Altamaha Sound GA to Flagler Beach FL out to 60 nm
809 PM EST Tue Jan 18 2022

High pressure will be over the waters through Wednesday with light winds expected. Winds will shift to southwesterly Thursday as a cold front approaches from the northwest. The front will cross the waters on Friday, then elevated winds are expected Friday night into the weekend as a coastal low develops. High pressure will build to the west early next week.

Gulf Stream
The approximate location of the west wall of the Gulf Stream as of Jan 15, 2022 at 1200 UTC...
- 37 nautical miles east northeast of Flagler Beach.
- 46 nautical miles east of Saint Augustine Beach.
- 61 nautical miles east of Jacksonville Beach.
- 68 nautical miles east southeast of St Simons Island.
Area Forecast Discussion
National Weather Service Jacksonville FL
1237am EST Wednesday Jan 19 2022

16pm EST]... Near Term - Through Tonight
With high pressure shifting over the area, very light winds, and only a few thin cirrus clouds tonight, radiational cooling is expected to take off after sunset. Lows tonight are expected to be cold once again, most of the area will drop down into the 30s and only a few spots along the NE FL coast will see lows in the lower 40s. Light onshore winds at the coast will help to increase moisture just enough across the area to increase frost formation tonight. A Freeze Warning has been issued for inland SE GA, the Suwannee Valley, and a portion in inland NE FL where a light freeze and widespread frost are expected. A Frost Advisory has also been issued for for the rest of inland NE FL and coastal SE GA where frost formation is expected.

Short Term - Wednesday Through Thursday Night
On Wednesday, our local area will still be under the influence of surface high pressure as it shifts just offshore into the Atlantic. Dry weather with light winds under mostly clear skies will lead us into a fairly nice day. High temperatures will reach into the middle 60s to lower 70s, and low temperatures Wednesday night will be warmer than the previous two nigheights with temperatures in the 40s inland and lower 50s at the coast.

On Thursday, an upper level shortwave trough digging southwards over the Great Lakes region will push a cold front towards the Southeast US and arctic high pressure will move down into the upper Mid-west. Scattered to numerous showers are expected ahead of the front on Thursday, but model solutions still differ on the amount of rain expected. The ECMWF (European Centre for Medium-Range Weather Forecasts) is much more aggressive with rainfall while the Canadian and GFS are a bit drier. The front is expected to move over the area Thursday night. Temperatures will be a few degrees warmer on Thursday due to southwest flow ahead of the front, high temperatures are expected to be in the upper 60s to middle 70s. A range of low temperatures are expected Thursday night with areas in SE GA behind the front in the lower to middle 40s and areas in NE FL ahead of the front in the lower 50s.

Long Term - Friday Through Tuesday

There is quite a spread in model solutions for the long term period, so there is high uncertainty in the forecast. The front will likely become quasi-stationary over our area on Friday as the upper level shortwave trough digs towards the Mid-Atlantic region. Models agree that another shortwave trough near Texas on Friday will interact with the northern shortwave and pass over our area Friday night or Saturday. Rain is expected to continue over our area Friday through Saturday, but it is uncertain how much rain we will get.

The ECMWF brings the northern shortwave more south and advances the southern shortwave faster than the GFS, allowing the shortwaves to phase up and produce a strong low pressure system off the Carolina coast next weekend. The GFS and the Canadian advance the southern shortwave slower, limiting the strength of the developing low off the coast. The ECMWF also has a much wetter solution than the GFS and Canadian as the southern shortwave moves over our area Friday night or Saturday.

There is a low chance of some light freezing rain near the Altamaha River in inland SE GA late Friday night/Saturday morning as cold arctic air pushes towards the Southeast US and interacts with precipitation over the area. Regardless of if we get any freezing rain or not, inland SE GA will experience cold rain with expected highs only in the 40s Friday and Saturday and lows in the 30s Friday night/Saturday morning. The rest of the area will see below average temperatures as well Friday and Saturday, and we could see frost and freeze conditions Saturday night.

Rain will be moving out of the area Saturday night, and will be over by Sunday. Dry weather is expected Sunday and Monday, then rain chances will return with another shortwave expected to move over the area on Tuesday. Temperatures will gradually increase Sunday through Tuesday, but still remain a bit below average.

Marine
High pressure will be over the waters through Wednesday with light winds expected. Winds will shift to southwesterly Thursday as a cold front approaches from the northwest. The front will cross the waters on Friday, then elevated winds are expected Friday night into the weekend as a coastal low develops. High pressure will build to the west early next week.

Rip Currents
Low risk at all area beaches through Wednesday.

Fire Weather
High pressure will shift over the area tonight and Wednesday, and winds will be light and variable. Weak transport winds will result in low daytime dispersions for inland SE GA and along the NE FL and SE GA coasts as well as along the St. Johns River basin. Elsewhere, dispersions will be on the lower side, generally 20-30 units. Winds will increase from the southwest on Thursday, resulting in better daytime dispersion values, although far inland SE GA may still have some patches of low dispersions. A cold front will approach the area on Thursday with showers beginning Thursday afternoon. Significant is fog not expected. Freeze and frost conditions are expected for most of the area late tonight into early Wednesday morning.

NOAA Jacksonville FL Office: Watches - Warnings - Advisories
FL...Freeze Warning until 8am EST this morning for Baker-Bradford- Eastern Alachua-Gilchrist-Hamilton-Inland Nassau-Northern Columbia-Southern Columbia-Suwannee-Union-Western Alachua- Western Duval-Western Marion.

Frost Advisory until 8am EST this morning for Central Marion- Coastal Duval-Coastal Nassau-Eastern Clay-Eastern Marion- Eastern Putnam-Inland Flagler-Inland St. Johns-South Central Duval-Trout River-Western Clay-Western Putnam.

GA...Freeze Warning until 8am EST this morning for Appling-Atkinson- Bacon-Brantley-Clinch-Coffee-Echols-Inland Camden-Inland Glynn-Jeff Davis-Northeastern Charlton-Northern Ware-Pierce- Southern Ware-Wayne-Western Charlton.

Frost Advisory until 8am EST this morning for Coastal Camden- Coastal Glynn.

AM...None.