FZCA52 TJSJ 210746 CWFSJU Coastal Waters Forecast National Weather Service San Juan PR 346 AM AST Tue Apr 21 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. AMZ700-212030- 346 AM AST Tue Apr 21 2026 .Synopsis for Puerto Rico and the U.S. Virgin Islands Waters... A high-pressure system over the north-central Atlantic will promote gentle to moderate easterly winds, with seas in the 3 to 5 foot range today. Winds and seas will slightly diminish tonight. A weak frontal boundary north of the region, and a brief pulse of northerly swell spreading across the Atlantic waters, will cause winds to back from the northeast. As a result, seas will increase to 5 to 6 feet from Wednesday night into Thursday. Small craft should exercise caution in the offshore Atlantic waters and local passages during this time. Winds will then veer to an east to southeast direction by the end of the workweek, then becoming more southerly to end the weekend. $$ AMZ711-212030- Atlantic Waters of Puerto Rico and USVI from 10 NM to 19.5N- 346 AM AST Tue Apr 21 2026 .TODAY...East winds 10 to 15 knots, diminishing to 5 to 10 knots this afternoon. Seas 4 to 5 feet, occasionally to 6 feet. Wave Detail: East 4 feet at 8 seconds and northeast 1 foot at 11 seconds. Isolated showers. .TONIGHT...Northeast winds 5 to 10 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 8 seconds and northeast 1 foot at 11 seconds. .WEDNESDAY...East winds 5 to 10 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 3 feet at 8 seconds and northwest 2 feet at 11 seconds. .WEDNESDAY NIGHT...Northeast winds 5 to 10 knots. Seas 4 to 6 feet, occasionally to 8 feet. Wave Detail: North 6 feet at 10 seconds and east 3 feet at 8 seconds. .THURSDAY...East winds 5 to 10 knots. Seas around 6 feet, occasionally to 8 feet. Wave Detail: North 6 feet at 10 seconds and east 2 feet at 8 seconds. .THURSDAY NIGHT...East winds 5 to 10 knots. Seas 5 to 6 feet, occasionally to 8 feet. Wave Detail: North 5 feet at 9 seconds and east 2 feet at 8 seconds. .FRIDAY...East winds 5 to 10 knots. Seas around 5 feet, occasionally to 6 feet. Scattered showers. .FRIDAY NIGHT...East winds 5 to 10 knots. Seas 4 to 5 feet, occasionally to 6 feet. Scattered showers. .SATURDAY...Southeast winds 5 to 10 knots. Seas around 4 feet, occasionally to 5 feet. Scattered showers. .SATURDAY NIGHT...Southeast winds 5 to 10 knots. Seas 3 to 4 feet, occasionally to 5 feet. Scattered showers. $$ AMZ712-212030- Coastal Waters of Northern Puerto Rico out 10 NM- 346 AM AST Tue Apr 21 2026 .TODAY...East winds 5 to 10 knots, increasing to 10 to 15 knots with gusts up to 20 knots this afternoon. Seas around 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 8 seconds and northeast 2 feet at 11 seconds. Isolated showers. .TONIGHT...East winds 5 to 10 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 3 feet at 8 seconds and northeast 1 foot at 11 seconds. Scattered showers in the evening. .WEDNESDAY...East winds 5 to 10 knots. Seas around 3 feet. Wave Detail: Northeast 3 feet at 8 seconds and northeast 1 foot at 10 seconds. .WEDNESDAY NIGHT...East winds 5 to 10 knots. Seas 3 to 5 feet, occasionally to 6 feet. Wave Detail: North 5 feet at 10 seconds and northeast 3 feet at 8 seconds. .THURSDAY...East winds 5 to 10 knots. Seas 5 to 6 feet, occasionally to 8 feet. Wave Detail: North 6 feet at 10 seconds and east 2 feet at 8 seconds. .THURSDAY NIGHT...East winds 5 to 10 knots. Seas 5 to 6 feet, occasionally to 8 feet. Wave Detail: North 5 feet at 9 seconds and east 2 feet at 8 seconds. Scattered showers. .FRIDAY...East winds 5 to 10 knots. Seas 4 to 5 feet, occasionally to 6 feet. Numerous showers in the afternoon. .FRIDAY NIGHT...Southeast winds 5 to 10 knots. Seas 4 to 5 feet, occasionally to 6 feet. .SATURDAY...Southeast winds 5 to 10 knots, becoming east in the afternoon. Seas around 4 feet, occasionally to 5 feet. Scattered showers in the morning, then numerous showers in the afternoon. .SATURDAY NIGHT...Southeast winds 5 to 10 knots. Seas 3 to 4 feet, occasionally to 5 feet. $$ AMZ716-212030- Coastal Waters from Cabo San Juan to the waters between Anegada Island and Virgin Gorda and North 10 NM- 346 AM AST Tue Apr 21 2026 .TODAY...East winds 5 to 10 knots with gusts up to 20 knots. Seas 2 to 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 7 seconds and northeast 1 foot at 11 seconds. Isolated showers. .TONIGHT...Northeast winds around 10 knots. Seas 2 to 3 feet. Wave Detail: Northeast 2 feet at 7 seconds and northeast 1 foot at 11 seconds. Scattered showers in the evening. .WEDNESDAY...Northeast winds 5 to 10 knots. Seas 2 to 3 feet. Wave Detail: Northeast 2 feet at 7 seconds and northeast 1 foot at 10 seconds. .WEDNESDAY NIGHT...Northeast winds 5 to 10 knots. Seas 2 to 3 feet. Wave Detail: Northeast 2 feet at 7 seconds and northwest 2 feet at 11 seconds. .THURSDAY...East winds 5 to 10 knots. Seas 3 to 5 feet, occasionally to 6 feet. Wave Detail: North 5 feet at 10 seconds and east 2 feet at 7 seconds. Scattered showers in the morning. .THURSDAY NIGHT...East winds 5 to 10 knots. Seas 4 to 6 feet, occasionally to 8 feet. Wave Detail: Northeast 5 feet at 9 seconds and north 5 feet at 10 seconds. .FRIDAY...East winds 5 to 10 knots. Seas 3 to 5 feet, occasionally to 6 feet. .FRIDAY NIGHT...East winds around 10 knots. Seas 3 to 4 feet, occasionally to 5 feet. .SATURDAY...Southeast winds around 10 knots. Seas 3 to 4 feet, occasionally to 5 feet. .SATURDAY NIGHT...Southeast winds around 10 knots. Seas 3 to 4 feet, occasionally to 5 feet. Scattered showers. $$ AMZ723-212030- Anegada Passage east of Virgin Gorda and Saint Croix south to 17N- 346 AM AST Tue Apr 21 2026 .TODAY...East winds 10 to 15 knots with gusts up to 20 knots, becoming northeast 5 to 10 knots late. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 7 seconds and northeast 1 foot at 11 seconds. .TONIGHT...Northeast winds 10 to 15 knots with gusts up to 20 knots. Seas around 3 feet. Wave Detail: Northeast 3 feet at 7 seconds and northeast 1 foot at 11 seconds. .WEDNESDAY...Northeast winds around 10 knots. Seas around 3 feet. Wave Detail: Northeast 3 feet at 7 seconds and northeast 1 foot at 10 seconds. .WEDNESDAY NIGHT...Northeast winds around 10 knots. Seas around 3 feet. Wave Detail: Northeast 2 feet at 8 seconds and northeast 1 foot at 11 seconds. .THURSDAY...East winds 5 to 10 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: Northeast 2 feet at 5 seconds and northeast 2 feet at 12 seconds. Scattered showers in the morning. .THURSDAY NIGHT...East winds 5 to 10 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: North 3 feet at 12 seconds and northeast 2 feet at 6 seconds. .FRIDAY...East winds 5 to 10 knots. Seas 3 to 4 feet, occasionally to 5 feet. .FRIDAY NIGHT...East winds around 10 knots. Seas 3 to 4 feet, occasionally to 5 feet. .SATURDAY...Southeast winds 5 to 10 knots. Seas 3 to 4 feet, occasionally to 5 feet. .SATURDAY NIGHT...Southeast winds 5 to 10 knots. Seas around 3 feet. Scattered showers. $$ AMZ726-212030- Coastal waters east of Puerto Rico, around Vieques, and around and just north of Culebra and Saint John- 346 AM AST Tue Apr 21 2026 .TODAY...East winds 10 to 15 knots with gusts up to 20 knots, diminishing to 5 to 10 knots this afternoon. Seas 2 to 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 7 seconds. Isolated showers. .TONIGHT...Northeast winds around 10 knots. Seas 2 to 3 feet. Wave Detail: Northeast 3 feet at 7 seconds. Scattered showers in the evening. .WEDNESDAY...Northeast winds 5 to 10 knots. Seas 2 to 3 feet. Wave Detail: East 3 feet at 7 seconds. .WEDNESDAY NIGHT...Northeast winds 5 to 10 knots. Seas around 2 feet. Wave Detail: Northeast 2 feet at 7 seconds. .THURSDAY...East winds 5 to 10 knots. Seas 2 to 3 feet. Wave Detail: East 2 feet at 6 seconds. Scattered showers. .THURSDAY NIGHT...East winds 5 to 10 knots. Seas 2 to 4 feet, occasionally to 5 feet. Wave Detail: East 2 feet at 7 seconds. .FRIDAY...East winds 5 to 10 knots. Seas 2 to 4 feet, occasionally to 5 feet. .FRIDAY NIGHT...East winds 5 to 10 knots. Seas 2 to 3 feet. .SATURDAY...Southeast winds 5 to 10 knots. Seas 2 to 3 feet. Scattered showers in the afternoon. .SATURDAY NIGHT...Southeast winds 5 to 10 knots. Seas 2 to 3 feet. Scattered showers. $$ AMZ733-212030- Caribbean waters of Puerto Rico from 10 NM to 17N, including the coastal waters of Saint Croix- 346 AM AST Tue Apr 21 2026 .TODAY...East winds 5 to 10 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 7 seconds. Isolated showers. .TONIGHT...Northeast winds 10 to 15 knots with gusts up to 20 knots. Seas around 3 feet. Wave Detail: East 3 feet at 7 seconds. .WEDNESDAY...Northeast winds around 10 knots. Seas 2 to 3 feet. Wave Detail: East 3 feet at 7 seconds. .WEDNESDAY NIGHT...Northeast winds 10 to 15 knots with gusts up to 20 knots. Seas 2 to 3 feet. Wave Detail: Northeast 3 feet at 7 seconds. .THURSDAY...East winds 5 to 10 knots. Seas 2 to 3 feet. Wave Detail: East 3 feet at 6 seconds. .THURSDAY NIGHT...East winds 5 to 10 knots. Seas 2 to 3 feet. Wave Detail: East 2 feet at 6 seconds. .FRIDAY...East winds 5 to 10 knots. Seas 2 to 3 feet. .FRIDAY NIGHT...East winds around 10 knots. Seas 2 to 3 feet. .SATURDAY...Southeast winds 5 to 10 knots. Seas around 2 feet. Scattered showers in the afternoon. .SATURDAY NIGHT...Southeast winds 5 to 10 knots. Seas around 2 feet. Scattered showers. $$ AMZ735-212030- Coastal Waters of Southern Puerto Rico out 10 NM- 346 AM AST Tue Apr 21 2026 .TODAY...East winds 5 to 10 knots. Seas 2 to 4 feet, occasionally to 5 feet. Wave Detail: East 3 feet at 7 seconds. Isolated showers. .TONIGHT...Northeast winds 5 to 10 knots. Seas 2 to 3 feet. Wave Detail: East 3 feet at 7 seconds. .WEDNESDAY...East winds 5 to 10 knots. Seas 2 to 3 feet. Wave Detail: East 2 feet at 6 seconds. .WEDNESDAY NIGHT...Northeast winds 5 to 10 knots. Seas 2 to 3 feet. Wave Detail: East 2 feet at 6 seconds. .THURSDAY...East winds 5 to 10 knots. Seas around 2 feet. Wave Detail: East 2 feet at 5 seconds. Scattered showers in the afternoon. .THURSDAY NIGHT...East winds 5 to 10 knots. Seas around 2 feet. Wave Detail: East 2 feet at 5 seconds. .FRIDAY...East winds 5 to 10 knots. Seas around 2 feet. .FRIDAY NIGHT...East winds 5 to 10 knots. Seas around 2 feet. .SATURDAY...Southeast winds 5 to 10 knots. Seas around 2 feet. Scattered showers in the afternoon. .SATURDAY NIGHT...Southeast winds 5 to 10 knots. Seas around 2 feet. $$ AMZ741-212030- Mona Passage Southward to 17N- 346 AM AST Tue Apr 21 2026 .TODAY...East winds 5 to 10 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 7 seconds and northeast 1 foot at 11 seconds. Isolated showers. .TONIGHT...Northeast winds 5 to 10 knots, increasing to 10 to 15 knots after midnight. Seas around 3 feet. Wave Detail: East 3 feet at 7 seconds and northeast 1 foot at 11 seconds. .WEDNESDAY...East winds 10 to 15 knots with gusts up to 20 knots, becoming northeast 5 to 10 knots in the afternoon. Seas around 3 feet. Wave Detail: East 3 feet at 6 seconds and northeast 1 foot at11 seconds. .WEDNESDAY NIGHT...Northeast winds 10 to 15 knots with gusts up to 20 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: Northeast 3 feet at 6 seconds and north 3 feet at 10 seconds. .THURSDAY...East winds 5 to 10 knots. Seas 3 to 5 feet, occasionally to 6 feet. Wave Detail: North 4 feet at 10 seconds and east 3 feet at 6 seconds. .THURSDAY NIGHT...East winds 5 to 10 knots. Seas 4 to 5 feet, occasionally to 6 feet. Wave Detail: North 4 feet at 9 seconds and east 2 feet at 5 seconds. .FRIDAY...Southeast winds 5 to 10 knots. Seas 3 to 5 feet, occasionally to 6 feet. Scattered showers in the afternoon. .FRIDAY NIGHT...East winds 5 to 10 knots. Seas 3 to 4 feet, occasionally to 5 feet. .SATURDAY...Southeast winds 10 to 15 knots. Seas 3 to 4 feet, occasionally to 5 feet. .SATURDAY NIGHT...Southeast winds 5 to 10 knots. Seas 3 to 4 feet, occasionally to 5 feet. $$ AMZ742-212030- Coastal Waters of Northwestern Puerto Rico out 10 NM- 346 AM AST Tue Apr 21 2026 .TODAY...East winds 5 to 10 knots, diminishing to around 5 knots late this morning, then becoming north this afternoon. Seas 2 to 3 feet. Wave Detail: Northeast 2 feet at 7 seconds and northeast 1 foot at 11 seconds. Scattered showers with isolated thunderstorms this afternoon. .TONIGHT...Northeast winds 10 to 15 knots with gusts up to 20 knots. Seas 2 to 3 feet. Wave Detail: Northeast 2 feet at 6 seconds and northeast 1 foot at 11 seconds. .WEDNESDAY...Northeast winds 5 to 10 knots, becoming north 10 to 15 knots with gusts up to 20 knots in the afternoon. Seas 2 to 3 feet. Wave Detail: Northeast 2 feet at 4 seconds and northeast 1 foot at 11 seconds. .WEDNESDAY NIGHT...Northeast winds 10 to 15 knots with gusts up to 20 knots, becoming east 5 to 10 knots after midnight. Seas 2 to 3 feet. Wave Detail: North 3 feet at 11 seconds and northeast 2 feet at 4 seconds. .THURSDAY...East winds 5 to 10 knots. Seas 4 to 6 feet, occasionally to 8 feet. Wave Detail: North 5 feet at 10 seconds. Scattered showers in the afternoon. .THURSDAY NIGHT...East winds 5 to 10 knots. Seas 3 to 5 feet, occasionally to 6 feet. Wave Detail: North 5 feet at 9 seconds. Scattered showers. .FRIDAY...East winds around 5 knots. Seas 3 to 5 feet, occasionally to 6 feet. Scattered showers in the afternoon. .FRIDAY NIGHT...East winds around 5 knots. Seas 2 to 4 feet, occasionally to 5 feet. .SATURDAY...Southeast winds 5 to 10 knots, becoming south 10 to 15 knots in the afternoon. Seas 2 to 4 feet, occasionally to 5 feet. Scattered showers in the afternoon. .SATURDAY NIGHT...Southeast winds 10 to 15 knots, diminishing to 5 to 10 knots after midnight. Seas 2 to 4 feet, occasionally to 5 feet. Winds and seas higher in and near thunderstorms. $$ AMZ745-212030- Coastal Waters of Southwestern Puerto Rico out 10 NM- 346 AM AST Tue Apr 21 2026 .TODAY...East winds 5 to 10 knots, becoming south early this afternoon, then becoming northeast around 5 knots late. Seas around 2 feet. Wave Detail: Southeast 2 feet at 6 seconds. Numerous showers with isolated thunderstorms early this afternoon. Scattered showers with isolated thunderstorms late. .TONIGHT...Northeast winds 5 to 10 knots. Seas around 2 feet. Wave Detail: Northeast 2 feet at 6 seconds. .WEDNESDAY...East winds around 5 knots, becoming northwest in the afternoon. Seas around 2 feet. Wave Detail: North 1 foot at 3 seconds and east 1 foot at 5 seconds. Scattered showers in the afternoon. .WEDNESDAY NIGHT...Northeast winds 5 to 10 knots. Seas around 2 feet. Wave Detail: Northwest 2 feet at 8 seconds and southeast 1 foot at 5 seconds. .THURSDAY...East winds 5 to 10 knots. Seas 2 to 4 feet, occasionally to 5 feet. Wave Detail: Northwest 4 feet at 10 seconds and east 1 foot at 4 seconds. Scattered showers in the afternoon. .THURSDAY NIGHT...East winds 5 to 10 knots. Seas 2 to 4 feet, occasionally to 5 feet. Wave Detail: Northwest 4 feet at 10 seconds. .FRIDAY...Southeast winds 5 to 10 knots. Seas 2 to 4 feet, occasionally to 5 feet. Scattered showers in the afternoon. .FRIDAY NIGHT...East winds 5 to 10 knots. Seas 2 to 3 feet. .SATURDAY...Southeast winds 5 to 10 knots, increasing to 10 to 15 knots in the afternoon. Seas 2 to 3 feet. .SATURDAY NIGHT...Southeast winds 5 to 10 knots. Seas 2 to 3 feet. Winds and seas higher in and near thunderstorms. $$