National Weather Service Marine Forecast FZCA52 TJSJ

FZCA52 TJSJ 202007
CWFSJU

Coastal Waters Forecast
National Weather Service San Juan PR
407 PM AST Thu Aug 20 2026

Puerto Rico and the U.S. Virgin Islands Waters

Seas are provided as a range of the average height of the highest 1/3 of the waves...along with the occasional height of the average highest 10 percent of the waves.

AMZ700-210915
407 PM AST Thu Aug 20 2026

Synopsis for Puerto Rico and the U.S. Virgin Islands Waters

Moderate to locally fresh easterly winds will continue today, maintaining locally choppy conditions across portions of the offshore waters and local passages. Winds will gradually diminish from Friday into the Weekend, though occasionally breezy conditions may persist across the more exposed waters. Marine conditions will gradually deteriorate again Sunday into early next week as winds increase.

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AMZ711-210915
Atlantic Waters of Puerto Rico and USVI from 10 NM to 19.5N
407 PM AST Thu Aug 20 2026

SMALL CRAFT SHOULD EXERCISE CAUTION

TONIGHT
East winds 15 to 20 knots with gusts up to 30 knots. Seas 4 to 5 feet, occasionally to 6 feet. Wave Detail: East 4 feet at 7 seconds. Isolated showers after midnight.

FRIDAY
East winds 15 to 20 knots with gusts up to 25 knots. Seas around 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 7 seconds.

FRIDAY NIGHT
East winds around 15 knots with gusts up to 25 knots. Seas 4 to 5 feet, occasionally to 6 feet. Wave Detail: East 4 feet at 7 seconds. Scattered showers after midnight.

SATURDAY
East winds 10 to 15 knots with gusts up to 25 knots. Seas around 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 7 seconds. Scattered showers in the morning.

SATURDAY NIGHT
East winds 10 to 15 knots with gusts up to 25 knots. Seas around 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 8 seconds. Scattered showers.

SUNDAY
East winds 10 to 15 knots with gusts up to 25 knots. Seas around 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 7 seconds.

SUNDAY NIGHT
East winds 15 to 20 knots with gusts up to 25 knots. Seas around 4 feet, occasionally to 5 feet.

MONDAY
East winds around 15 knots. Seas around 4 feet, occasionally to 5 feet.

MONDAY NIGHT
East winds 15 to 20 knots. Seas 4 to 5 feet, occasionally to 6 feet.

TUESDAY
East winds 15 to 20 knots, increasing to 20 to 25 knots in the afternoon. Seas 4 to 6 feet, occasionally to 8 feet.

TUESDAY NIGHT
East winds 20 to 25 knots, diminishing to 15 to 20 knots after midnight. Seas 5 to 6 feet, occasionally to 8 feet. Scattered showers.

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AMZ712-210915
Coastal Waters of Northern Puerto Rico out 10 NM
407 PM AST Thu Aug 20 2026

SMALL CRAFT SHOULD EXERCISE CAUTION

TONIGHT
East winds 15 to 20 knots with gusts up to 30 knots, diminishing to 10 to 15 knots with gusts up to 25 knots late this evening and overnight. Seas 3 to 5 feet, occasionally to 6 feet. Wave Detail: Northeast 4 feet at 7 seconds. Isolated showers.

FRIDAY
East winds 10 to 15 knots, increasing to 15 to 20 knots in the afternoon. Gusts up to 30 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: Northeast 4 feet at 7 seconds.

FRIDAY NIGHT
East winds 15 to 20 knots, diminishing to 10 to 15 knots after midnight. Seas 3 to 5 feet, occasionally to 6 feet. Wave Detail: East 4 feet at 5 seconds and northeast 4 feet at 8 seconds.

SATURDAY
East winds 10 to 15 knots, increasing to 15 to 20 knots in the afternoon. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: Northeast 4 feet at 7 seconds.

SATURDAY NIGHT
East winds 15 to 20 knots, diminishing to 10 to 15 knots after midnight. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: Northeast 4 feet at 7 seconds. Scattered showers.

SUNDAY
East winds 10 to 15 knots with gusts up to 20 knots, increasing to 15 to 20 knots with gusts up to 30 knots in the afternoon. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: Northeast 4 feet at 7 seconds. Scattered showers in the morning.

SUNDAY NIGHT
East winds 15 to 20 knots, diminishing to 10 to 15 knots after midnight. Seas 3 to 4 feet, occasionally to 5 feet. Scattered showers.

MONDAY
East winds 10 to 15 knots, increasing to 15 to 20 knots in the afternoon. Seas 3 to 4 feet, occasionally to 5 feet. Scattered showers in the morning.

MONDAY NIGHT
East winds 15 to 20 knots, diminishing to 10 to 15 knots after midnight. Seas 3 to 4 feet, occasionally to 5 feet.

TUESDAY
East winds 10 to 15 knots, increasing to 15 to 20 knots in the afternoon. Seas 3 to 4 feet, occasionally to 5 feet.

TUESDAY NIGHT
East winds 10 to 15 knots. Seas 4 to 5 feet, occasionally to 6 feet. Scattered showers.

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AMZ716-210915
Coastal Waters from Cabo San Juan to the waters between Anegada Island and Virgin Gorda and North 10 NM
407 PM AST Thu Aug 20 2026

SMALL CRAFT SHOULD EXERCISE CAUTION

TONIGHT
East winds 15 to 20 knots with gusts up to 25 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 3 feet at 5 seconds and north 1 foot at 8 seconds. Isolated showers after midnight.

FRIDAY
East winds around 15 knots with gusts up to 20 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 3 feet at 5 seconds and northeast 2 feet at 8 seconds.

FRIDAY NIGHT
East winds around 15 knots with gusts up to 20 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 3 feet at 5 seconds and northeast 2 feet at 8 seconds. Scattered showers after midnight.

SATURDAY
East winds 10 to 15 knots with gusts up to 20 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 3 feet at 5 seconds and northeast 1 foot at 8 seconds. Scattered showers.

SATURDAY NIGHT
East winds 10 to 15 knots with gusts up to 25 knots. Seas 2 to 4 feet, occasionally to 5 feet. Wave Detail: East 3 feet at 5 seconds and northeast 2 feet at 8 seconds. Scattered showers.

SUNDAY
East winds around 15 knots with gusts up to 20 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 3 feet at 5 seconds and northeast 1 foot at 8 seconds.

SUNDAY NIGHT
East winds around 15 knots with gusts up to 25 knots. Seas 3 to 4 feet, occasionally to 5 feet.

MONDAY
East winds around 15 knots. Seas 3 to 4 feet, occasionally to 5 feet. Scattered showers in the morning.

MONDAY NIGHT
East winds 15 to 20 knots. Seas 3 to 4 feet, occasionally to 5 feet.

TUESDAY
East winds around 20 knots. Seas 3 to 4 feet, occasionally to 5 feet.

TUESDAY NIGHT
East winds 15 to 20 knots. Seas 3 to 4 feet, occasionally to 5 feet. Scattered showers.

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AMZ723-210915
Anegada Passage east of Virgin Gorda and Saint Croix south to 17N
407 PM AST Thu Aug 20 2026

SMALL CRAFT SHOULD EXERCISE CAUTION

TONIGHT
East winds 15 to 20 knots with gusts up to 25 knots. Seas 4 to 5 feet, occasionally to 6 feet. Wave Detail: Northeast 5 feet at 7 seconds. Isolated showers late.

FRIDAY
East winds around 15 knots with gusts up to 25 knots. Seas 4 to 5 feet, occasionally to 6 feet. Wave Detail: East 5 feet at 7 seconds.

FRIDAY NIGHT
East winds 15 to 20 knots with gusts up to 25 knots. Seas around 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 7 seconds.

SATURDAY
East winds 10 to 15 knots with gusts up to 25 knots. Seas around 4 feet, occasionally to 5 feet. Wave Detail: Northeast 4 feet at 7 seconds. Scattered showers in the morning.

SATURDAY NIGHT
East winds 15 to 20 knots with gusts up to 25 knots. Seas around 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 5 seconds and northeast 2 feet at 8 seconds.

SUNDAY
East winds around 15 knots with gusts up to 25 knots. Seas around 4 feet, occasionally to 5 feet. Wave Detail: Northeast 4 feet at 7 seconds.

SUNDAY NIGHT
East winds around 15 knots with gusts up to 25 knots. Seas around 4 feet, occasionally to 5 feet. Scattered showers.

MONDAY
East winds around 15 knots. Seas around 4 feet, occasionally to 5 feet.

MONDAY NIGHT
East winds 15 to 20 knots. Seas 4 to 6 feet, occasionally to 8 feet.

TUESDAY
East winds around 20 knots. Seas around 6 feet, occasionally to 8 feet.

TUESDAY NIGHT
East winds 15 to 20 knots. Seas 5 to 6 feet, occasionally to 8 feet. Scattered showers.

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AMZ726-210915
Coastal waters east of Puerto Rico, around Vieques, and around and just north of Culebra and Saint John
407 PM AST Thu Aug 20 2026

SMALL CRAFT SHOULD EXERCISE CAUTION

TONIGHT
East winds 15 to 20 knots with gusts up to 25 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 6 seconds. Isolated showers.

FRIDAY
East winds around 15 knots with gusts up to 25 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 7 seconds.

FRIDAY NIGHT
East winds around 15 knots with gusts up to 25 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 3 feet at 7 seconds. Scattered showers after midnight.

SATURDAY
East winds 10 to 15 knots with gusts up to 20 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 3 feet at 7 seconds.

SATURDAY NIGHT
East winds 10 to 15 knots with gusts up to 25 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 7 seconds. Scattered showers.

SUNDAY
East winds around 15 knots with gusts up to 25 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 5 seconds.

SUNDAY NIGHT
East winds around 15 knots with gusts up to 25 knots. Seas 3 to 4 feet, occasionally to 5 feet.

MONDAY
East winds around 15 knots. Seas 3 to 4 feet, occasionally to 5 feet. Scattered showers in the morning.

MONDAY NIGHT
East winds 15 to 20 knots. Seas 3 to 4 feet, occasionally to 5 feet.

TUESDAY
East winds 15 to 20 knots. Seas 4 to 6 feet, occasionally to 8 feet.

TUESDAY NIGHT
East winds 15 to 20 knots. Seas 4 to 5 feet, occasionally to 6 feet. Scattered showers.

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AMZ733-210915
Caribbean waters of Puerto Rico from 10 NM to 17N, including the coastal waters of Saint Croix
407 PM AST Thu Aug 20 2026

SMALL CRAFT SHOULD EXERCISE CAUTION

TONIGHT
East winds 15 to 20 knots with gusts up to 30 knots. Seas 4 to 5 feet, occasionally to 6 feet. Wave Detail: East 5 feet at 6 seconds. Isolated showers late.

FRIDAY
East winds 15 to 20 knots with gusts up to 30 knots. Seas 4 to 6 feet, occasionally to 8 feet. Wave Detail: East 5 feet at 7 seconds.

FRIDAY NIGHT
East winds 15 to 20 knots with gusts up to 25 knots. Seas 4 to 5 feet, occasionally to 6 feet. Wave Detail: East 5 feet at 7 seconds.

SATURDAY
East winds 15 to 20 knots, diminishing to 10 to 15 knots in the afternoon. Seas 4 to 5 feet, occasionally to 6 feet. Wave Detail: East 5 feet at 6 seconds.

SATURDAY NIGHT
East winds 10 to 15 knots, increasing to 15 to 20 knots after midnight. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 6 seconds.

SUNDAY
East winds 15 to 20 knots with gusts up to 25 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 6 seconds.

SUNDAY NIGHT
East winds 15 to 20 knots with gusts up to 25 knots. Seas around 4 feet, occasionally to 5 feet.

MONDAY
East winds around 15 knots. Seas around 4 feet, occasionally to 5 feet. Scattered showers in the morning.

MONDAY NIGHT
East winds 15 to 20 knots. Seas around 4 feet, occasionally to 5 feet.

TUESDAY
East winds 15 to 20 knots. Seas 4 to 5 feet, occasionally to 6 feet.

TUESDAY NIGHT
East winds 15 to 20 knots. Seas around 5 feet, occasionally to 6 feet. Scattered showers.

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AMZ735-210915
Coastal Waters of Southern Puerto Rico out 10 NM
407 PM AST Thu Aug 20 2026

SMALL CRAFT SHOULD EXERCISE CAUTION

TONIGHT
East winds 15 to 20 knots, diminishing to 10 to 15 knots after midnight. Gusts up to 30 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 6 seconds. Isolated showers late.

FRIDAY
East winds 10 to 15 knots, increasing to 15 to 20 knots in the afternoon. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 7 seconds.

FRIDAY NIGHT
East winds 15 to 20 knots, diminishing to 10 to 15 knots after midnight. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 7 seconds.

SATURDAY
East winds 10 to 15 knots with gusts up to 20 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 7 seconds.

SATURDAY NIGHT
East winds 10 to 15 knots with gusts up to 25 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 6 seconds.

SUNDAY
East winds 10 to 15 knots with gusts up to 20 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 6 seconds.

SUNDAY NIGHT
East winds 10 to 15 knots with gusts up to 25 knots. Seas 3 to 4 feet, occasionally to 5 feet.

MONDAY
East winds 10 to 15 knots. Seas 3 to 4 feet, occasionally to 5 feet.

MONDAY NIGHT
East winds 10 to 15 knots. Seas 3 to 4 feet, occasionally to 5 feet.

TUESDAY
East winds 10 to 15 knots, increasing to 15 to 20 knots in the afternoon. Seas 3 to 4 feet, occasionally to 5 feet.

TUESDAY NIGHT
East winds 15 to 20 knots. Seas 3 to 4 feet, occasionally to 5 feet.

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AMZ741-210915
Mona Passage Southward to 17N
407 PM AST Thu Aug 20 2026

SMALL CRAFT SHOULD EXERCISE CAUTION

TONIGHT
East winds 15 to 20 knots with gusts up to 30 knots. Seas 4 to 6 feet, occasionally to 8 feet. Wave Detail: East 6 feet at 7 seconds. Scattered showers early this evening.

FRIDAY
East winds 15 to 20 knots with gusts up to 30 knots. Seas 4 to 6 feet, occasionally to 8 feet. Wave Detail: East 6 feet at 7 seconds.

FRIDAY NIGHT
East winds 15 to 20 knots with gusts up to 25 knots. Seas 4 to 6 feet, occasionally to 8 feet. Wave Detail: East 5 feet at 7 seconds.

SATURDAY
East winds 10 to 15 knots with gusts up to 25 knots. Seas 3 to 5 feet, occasionally to 6 feet. Wave Detail: East 5 feet at 7 seconds. Scattered showers in the afternoon.

SATURDAY NIGHT
East winds 10 to 15 knots with gusts up to 25 knots. Seas 3 to 5 feet, occasionally to 6 feet. Wave Detail: East 5 feet at 7 seconds. Scattered showers in the evening.

SUNDAY
East winds 15 to 20 knots, diminishing to 10 to 15 knots in the afternoon. Seas 3 to 5 feet, occasionally to 6 feet. Wave Detail: East 5 feet at 6 seconds.

SUNDAY NIGHT
East winds 10 to 15 knots, increasing to 15 to 20 knots after midnight. Seas 3 to 5 feet, occasionally to 6 feet.

MONDAY
East winds 15 to 20 knots, diminishing to 10 to 15 knots in the afternoon. Seas 3 to 5 feet, occasionally to 6 feet. Scattered showers in the afternoon.

MONDAY NIGHT
East winds 10 to 15 knots. Seas 3 to 5 feet, occasionally to 6 feet. Scattered showers.

TUESDAY
East winds 10 to 15 knots, increasing to 15 to 20 knots in the afternoon. Seas 3 to 5 feet, occasionally to 6 feet.

TUESDAY NIGHT
East winds 15 to 20 knots. Seas 4 to 5 feet, occasionally to 6 feet.

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AMZ742-210915
Coastal Waters of Northwestern Puerto Rico out 10 NM
407 PM AST Thu Aug 20 2026

TONIGHT
East winds 10 to 15 knots, diminishing to 5 to 10 knots after midnight. Seas 2 to 3 feet. Wave Detail: Northeast 3 feet at 6 seconds. Scattered showers early this evening.

FRIDAY
East winds 5 to 10 knots, becoming northeast 10 to 15 knots in the afternoon. Seas 2 to 3 feet. Wave Detail: Northeast 3 feet at 7 seconds and southeast 2 feet at 6 seconds. Scattered showers in the afternoon.

FRIDAY NIGHT
East winds 10 to 15 knots with gusts up to 25 knots. Seas 2 to 4 feet, occasionally to 5 feet. Wave Detail: East 3 feet at 6 seconds.

SATURDAY
Northeast winds 5 to 10 knots. Seas 2 to 3 feet. Wave Detail: Northeast 2 feet at 6 seconds and southeast 1 foot at 5 seconds. Numerous showers in the afternoon.

SATURDAY NIGHT
East winds 10 to 15 knots with gusts up to 20 knots, diminishing to 5 to 10 knots after midnight. Seas 2 to 3 feet. Wave Detail: East 2 feet at 6 seconds.

SUNDAY
Northeast winds 5 to 10 knots. Seas 2 to 3 feet. Wave Detail: Northeast 2 feet at 6 seconds and south 1 foot at 5 seconds. Scattered showers in the afternoon.

SUNDAY NIGHT
East winds 5 to 10 knots. Seas 2 to 3 feet.

MONDAY
East winds 5 to 10 knots, becoming northeast 10 to 15 knots in the afternoon. Seas 2 to 3 feet. Numerous showers in the afternoon.

MONDAY NIGHT
East winds 10 to 15 knots. Seas 2 to 3 feet. Scattered showers.

TUESDAY
East winds 5 to 10 knots. Seas 2 to 3 feet. Scattered showers in the afternoon.

TUESDAY NIGHT
East winds 5 to 10 knots, increasing to 10 to 15 knots after midnight. Seas 2 to 4 feet, occasionally to 5 feet.

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AMZ745-210915
Coastal Waters of Southwestern Puerto Rico out 10 NM
407 PM AST Thu Aug 20 2026

SMALL CRAFT SHOULD EXERCISE CAUTION

TONIGHT
Southeast winds 15 to 20 knots with gusts up to 25 knots, becoming east 10 to 15 knots with gusts up to 25 knots late this evening and early morning, then diminishing to 5 to 10 knots late. Seas 2 to 3 feet. Wave Detail: Southeast 2 feet at 5 seconds and north 1 foot at 7 seconds. Isolated showers this evening.

FRIDAY
East winds 5 to 10 knots, becoming southeast in the afternoon. Seas 2 to 3 feet. Wave Detail: Southeast 2 feet at 6 seconds. Scattered showers in the afternoon.

FRIDAY NIGHT
East winds 5 to 10 knots. Seas 2 to 3 feet. Wave Detail: Southeast 2 feet at 5 seconds.

SATURDAY
East winds 5 to 10 knots. Seas around 2 feet. Wave Detail: Southeast 2 feet at 5 seconds. Scattered showers in the afternoon.

SATURDAY NIGHT
East winds 10 to 15 knots with gusts up to 20 knots, diminishing to 5 to 10 knots after midnight. Seas around 2 feet. Wave Detail: Southeast 2 feet at 5 seconds.

SUNDAY
East winds 5 to 10 knots with gusts up to 20 knots. Seas around 2 feet. Wave Detail: Southeast 2 feet at 5 seconds.

SUNDAY NIGHT
East winds 5 to 10 knots. Seas 2 to 3 feet.

MONDAY
East winds 5 to 10 knots. Seas around 2 feet.

MONDAY NIGHT
East winds 5 to 10 knots, diminishing to around 5 knots after midnight. Seas 2 to 3 feet.

TUESDAY
East winds 5 to 10 knots, becoming southeast 15 to 20 knots in the afternoon. Seas 2 to 3 feet. Scattered showers in the afternoon.

TUESDAY NIGHT
East winds 15 to 20 knots, diminishing to 10 to 15 knots after midnight. Seas 2 to 3 feet. Scattered showers.