Anegada Passage Southward to 17N Marine Forecast
| Rest Of Today...Southwest Winds 5 To 10 Knots. Seas 2 To 4 Feet With Occasional Seas Around 5 Feet. Dominant Period 11 Seconds. Isolated Showers. |
| Tonight...West Winds 5 To 10 Knots. Seas 2 To 4 Feet With Occasional Seas Around 5 Feet. Dominant Period 11 Seconds. Isolated Showers. |
| Thursday...West Winds 10 To 15 Knots. Seas 3 To 5 Feet With Occasional Seas Up To 6 Feet. Dominant Period 12 Seconds. Isolated Showers. |
| Thursday Night...North Winds 10 To 15 Knots. Seas 6 To 8 Feet With Occasional Seas Up To 10 Feet. Dominant Period 12 Seconds. Scattered Showers. |
| Friday...North Winds 10 To 15 Knots, Becoming Northeast. Seas 5 To 7 Feet With Occasional Seas Up To 9 Feet. Dominant Period 11 Seconds. Isolated Showers. |
| Saturday...Southeast Winds 5 To 10 Knots. Seas 6 To 8 Feet With Occasional Seas Up To 10 Feet. Dominant Period 12 Seconds. Isolated Showers. |
| Sunday...South Winds 5 To 10 Knots, Becoming East. Seas 5 To 7 Feet With Occasional Seas Up To 9 Feet. Dominant Period 14 Seconds. |
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Area Forecast Discussion National Weather Service San Juan PR 500am AST Tuesday July 15 2025 .KEY MESSAGES... * Hot temperatures, high humidity content, and southeasterly winds will promote an elevated heat risk across the lower elevations and urban areas of Puerto Rico through the end of the week. * Back to back tropical waves will increase shower and thunderstorm activity today and tomorrow. * A Saharan Air Layer with moderate to high concentrations of Saharan dust will promote hazy skies and poor air quality conditions on Thursday and Friday. * Increasing winds through midweek will promote choppy seas and a moderate risk of rip currents across most east and northern beaches of the islands. .SHORT TERM...Today through Thursday... An increase in shower frequency was seen overnight across the local Atlantic and Caribbean waters. These showers affected mainly the islands of St. Thomas and St. John, where Doppler radar estimated rainfall accumulations up to 0.50 inches. Nonetheless, St. Croix and eastern Puerto Rico received some showers with limited accumulations. Minimum temperatures were from the mid to upper 70s along the coastal and urban areas to the upper 60s to low 70s across the mountains. Winds were light from the east-southeast with land- breeze variations. A broad surface high pressure north of the area will maintain a east- southeast wind flow today. However, winds will become from the east by Wednesday as the surface high migrates eastward. A tropical wave that is currently crossing the Lesser Antilles will approach the islands today, increasing the moisture content with precipitable water (PWAT) values between 1.80 to 2.10 inches. A second tropical wave with its axis near longitude 50W will arrive into the area by Wednesday bringing additional moisture into the area through Thursday. Under the aforementioned weather pattern, showers and thunderstorms are expected each day in the islands. During the morning hours, scattered showers will be observed over the U.S. Virgin Islands and eastern Puerto Rico. Then, afternoon convective activity is likely over portions of central and western Puerto Rico, as well downwind from el Yunque into the San Juan metropolitan area and adjacent municipalities. At this time, there is a limited to elevated potential to observe ponding of water in roads and poorly drainage areas, as well as localized flooding in urban areas, roads and small streams. By Thursday, trailing moisture from a departing tropical wave will continue to enhance the development of showers and isolated thunderstorms across the islands during the day. However, a dense Saharan Air Layer (SAL) with moderate to high concentrations of dust particles will reach the Northeastern Caribbean and gradually moving across the region. Therefore, hazy skies, reduced visibility, and poor air quality conditions are anticipated through at least the weekend. Hot temperatures will continue to persist all week, with maximum temperatures reaching upper 80s to low 90s along the coastal and urban areas each day. Heat indices are expected to be above the 100 degrees Fahrenheit each day as well, with Thursday being the warmest day. Today, there is a Heat Advisory in effect for all coastal areas of Puerto Rico, including the Caguas Valley from 10am to 4pm AST. Residents and visitors, please be aware of these conditions and plan accordingly if planning to do outdoor activities under sun exposure. Long Term Friday through Tuesday... Hazy skies, reduced visibility, and poor air quality conditions will continue through Friday due to a lingering Saharan Air Layer. Winds will acquire a northeasterly component as a broad TUTT- induced trough approaches the eastern Caribbean. The combination of the limited moisture content with daytime heating and the sea breeze convergence will trigger afternoon showers with isolated thunderstorms over the southwest quadrant of PR. An advective weather pattern at night will then promote showers across the local waters and over portions of the USVI and northeastern PR. The TUTT-low and the induced low-level trough are expected to move across the northeastern Caribbean through the weekend. This will bring an increase in shower activity once again across the islands. A tropical wave is expected to move across the region on Monday, followed by another SAL (Saharan Air Layer) event on Tuesday. In general, these weather features will enhance the early morning convection between the USVI and eastern sections of PR, followed by afternoon thunderstorms over portions of the interior and western PR. Even though the SAL (Saharan Air Layer) is expected to bring hazy skies and drier mid-level air, the precipitable water content is forecast to range between normal to above normal levels through the end of the long-term period. Meanwhile, a deep layer ridge building from the central Atlantic into the northeastern Caribbean will push further west and away of the area the trough pattern and promote southeasterly winds by Saturday afternoon. This moist southeast flow will prevail through at least Tuesday, and hot temperatures are expected each day. Likely triggering Heat Advisory conditions across most coastal areas of PR. Marine A surface high pressure will strengthen over the western Atlantic early this week. Back to back tropical waves will move across the local waters today and on Wednesday. Therefore, moderate to locally fresh trades and choppy seas are expected across the regional waters through midweek. Increasing shower and thunderstorm activity is expected with the passage of the tropical waves. Hazy conditions due to Saharan dust are expected on Thursday and Friday. Beach Forecast There is a moderate risk of rip currents for the north and east facing beaches of Puerto Rico, Culebra, Vieques, and St. Croix. Life-threatening rip currents often occur in the vicinity of groins, jetties, reefs, and piers. The potential for isolated thunderstorm development will increase today and tomorrow across most coastal areas due to passing tropical waves. .SJU WATCHES/WARNINGS/ADVISORIES... PR... Heat Advisory from 10am this morning to 4pm AST this afternoon for PRZ001>005-007-008-010-011. VI...None. AM...None. |
San Juan Radar
Southeast Radar