Nation Weather Service Marine Forecast for St. Augustine, Florida

Coastal Waters Forecast Overview: St. Augustine, Florida

This marine weather forecast is issued by the National Weather Service in Jacksonville, Florida, providing crucial information for mariners navigating the coastal waters from Altamaha Sound, Georgia to Flagler Beach, Florida, extending out to 60 nautical miles. This detailed forecast, valid from 9:11 PM EST Sunday, February 23, 2025, is essential for anyone planning to be on the waters near St. Augustine.

Synopsis of Weather Systems Affecting Coastal Waters

A weak low-pressure system, currently located just south of coastal Louisiana, is expected to move southeastward across the southeastern Gulf of Mexico tonight and Monday. This system will track across South Florida on Monday night, bringing rainfall to our local waters overnight and into Monday. There’s a possibility of embedded thunderstorms, particularly in the offshore waters south of St. Augustine on Monday afternoon and night.

By early Tuesday morning, the low pressure will pivot northeastward over the northwestern Bahamas and then strengthen as it accelerates towards Bermuda. Following this system, weak high pressure will build eastward along the northern Gulf Coast on Tuesday night, becoming centered over our local waters early Wednesday morning. This high pressure will shift offshore by Wednesday afternoon, ahead of a cold front approaching the southeastern states on Wednesday night.

The cold front is predicted to sweep southeastward across our local waters on Thursday night, bringing showers. Gusty northwesterly winds will follow the frontal passage on Thursday night, shifting to northerly by Friday morning as another high-pressure system builds eastward along the northern Gulf Coast. Conditions are expected to improve by Friday evening as high pressure moves towards the Florida peninsula, leading to diminishing winds and seas.

Gulf Stream Location Near St. Augustine

As of February 22, 2025, at 1200 UTC, the approximate location of the west wall of the Gulf Stream is:

67 nautical miles east of Saint Augustine Beach.

This data is provided courtesy of the Naval Oceanographic Office and is vital for mariners navigating these waters.

Coastal Waters Forecast: Altamaha Sound to Flagler Beach, FL out to 20 NM

AMZ450-452-454

Rest of Tonight: South winds around 5 knots, becoming northwest. Seas around 2 feet, primarily from the east at 2 feet with a 9-second period. Intracoastal waters will be smooth. There is a chance of light rain this evening, becoming likely after midnight.
Monday: Northeast winds of 10 to 15 knots. Seas will be 2 to 3 feet, from the northeast at 3 feet with a 5-second period. Intracoastal waters will experience a light chop. Expect periods of rain.
Monday Night: Northeast winds of 10 to 15 knots. Seas 2 to 3 feet. Wave Detail: Northeast 3 feet at 5 seconds. Intracoastal waters a light chop. Periods of rain.
Tuesday: North winds of 15 to 20 knots. Seas 2 to 4 feet, occasionally reaching 5 feet, from the north at 4 feet with a 5-second period. Intracoastal waters will be choppy. There is a chance of light rain in the morning.
Tuesday Night: Northwest winds of 5 to 10 knots. Seas 2 to 4 feet, occasionally up to 5 feet, from the east at 3 feet with a 6-second period. Intracoastal waters will be mostly smooth.
Wednesday: North winds around 5 knots, becoming northeast at 5 to 10 knots in the afternoon. Seas 2 to 3 feet, from the east at 3 feet with a 7-second period. Intracoastal waters will be mostly smooth.
Wednesday Night: South winds of 5 to 10 knots, becoming southwest after midnight. Seas 2 to 3 feet, from the east at 3 feet with a 7-second period. Intracoastal waters will be mostly smooth.
Thursday: South winds of 5 to 10 knots, becoming southwest around 10 knots in the afternoon. Seas 2 to 3 feet. Intracoastal waters becoming a light chop. A slight chance of showers late in the afternoon.
Thursday Night: West winds around 15 knots, becoming northwest and increasing to 15 to 20 knots after midnight. Seas 2 to 4 feet, occasionally up to 5 feet. Intracoastal waters becoming choppy. A chance of showers.
Friday: North winds of 15 to 20 knots. Seas 2 to 4 feet, occasionally up to 5 feet. Intracoastal waters choppy. A slight chance of showers, mainly in the morning.

Coastal Waters Forecast: Altamaha Sound GA to Flagler Beach FL from 20 to 60 NM

AMZ470-472-474

Rest of Tonight: South winds around 5 knots, becoming west. Seas 2 to 3 feet, from the northeast at 2 feet with an 8-second period. A slight chance of light rain this evening, then rain likely after midnight.
Monday: Northeast winds increasing to 10 to 15 knots. Seas 2 to 3 feet, from the northeast at 3 feet with an 8-second period. Rain is likely in the morning, followed by showers with a slight chance of thunderstorms in the afternoon.
Monday Night: Northeast winds of 10 to 15 knots. Seas 2 to 4 feet, occasionally reaching 5 feet, from the northeast at 4 feet with a 5-second period. Showers are likely with a slight chance of thunderstorms.
Tuesday: North winds of 15 to 20 knots. Seas 3 to 5 feet, occasionally up to 6 feet, from the north at 5 feet with a 6-second period. A chance of rain during the morning.
Tuesday Night: Northwest winds of 5 to 10 knots. Seas 3 to 4 feet, occasionally up to 5 feet, from the east at 4 feet with a 7-second period.
Wednesday: North winds of 5 to 10 knots, becoming northeast during the afternoon. Seas 2 to 3 feet, from the east at 3 feet with a 7-second period.
Wednesday Night: Southeast winds of 5 to 10 knots, becoming south-southwest after midnight. Seas 2 to 3 feet, from the southeast at 3 feet with a 7-second period.
Thursday: Southwest winds of 5 to 10 knots, becoming west at 15 to 20 knots. Seas 3 to 5 feet, occasionally up to 6 feet. A slight chance of showers late in the afternoon.
Thursday Night: Southwest winds around 15 knots, becoming northwest and increasing to 15 to 20 knots after midnight. Seas building to 3 to 5 feet, occasionally up to 6 feet. A chance of showers.
Friday: North winds of 15 to 20 knots. Seas 4 to 5 feet, occasionally up to 6 feet. A chance of showers, mainly during the morning.

Important Note: Winds and seas may be higher in and near thunderstorms. Mariners should exercise caution and stay updated with the latest Nation Weather Service marine forecasts for St. Augustine, Florida.