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. |
| Area Forecast Discussion National Weather Service San Juan PR 213pm AST Tuesday September 22 2026 .Short Term(This evening through Thursday)... Issued at 210pm AST Tuesday September 22 2026 A generally fair weather pattern was observed across the islands during the morning hours, with some isolated showers affecting northeastern coastal sections. As the day progressed, temperatures warmed quickly, especially across coastal areas, where maximum temperatures increased into the upper 80s to lower 90s, while temperatures remained in the mid 80s across the mountainous sections. Heat indices across coastal areas ranged from the upper 90s to lower 100s, with the highest values observed across north- central Puerto Rico. As of 12 PM, satellite imagery showed increasing cloudiness developing over the El Yunque area and the mountains of western Puerto Rico, consistent with the onset of local and diurnal convection. Shower and thunderstorm activity developed across the San Juan metro area with the highest accumulations across Carolina with almost two inches according to the rainfall radar estimates. Showers also develop across the interior sections with strongest showers along Orocovis all the way trough Lares. This convection will continue for the rest of the afternoon at sunset. For Wednesday, a typical weather pattern will continue under the influence of a broad surface high pressure over the central Atlantic, resulting in east-southeast winds across the region. Under this wind flow, passing showers will continue to move across windward sections of Puerto Rico and the U.S. Virgin Islands, particularly during the morning hours, with minimal rainfall accumulations expected. As the day progresses, afternoon convection will mainly develop across interior and western Puerto Rico. With precipitable water values remaining near climatological normals, around 1.9 to 2.0 inches, sufficient moisture will be available to support afternoon convection. At the upper levels, an elongated Tropical Upper Tropospheric Trough (TUTT) will remain positioned north of the region, providing additional upper-level support and contributing to periods of instability. Therefore, showers and isolated thunderstorms are expected to develop during the afternoon, particularly across western and interior Puerto Rico. From late Wednesday into Thursday, a weak tropical wave is forecast to move across the region, increasing the frequency of showers and thunderstorms. Although the wave is expected to remain weak, an increase in moisture combined with instability aloft will favor more active weather across the islands and surrounding waters. Shower activity should gradually increase late Wednesday, with the most active period expected Wednesday night into Thursday as the wave crosses the region. Periods of locally heavy rainfall and isolated thunderstorms will be possible, with localized urban and small stream flooding possible in areas receiving persistent rainfall. Overall, the coverage and intensity of convection will remain dependent on the available moisture, local effects, and daytime heating. .Long Term(Friday through next Monday)... Issued at 210pm AST Tuesday September 22 2026 The main synoptic features during the long term period are a couple of multi level low pressure systems across the eastern Atlantic Ocean that will promote an east-to-southeast wind flow across the CWA. Winds are expected to bring calm-to-breezy conditions throughout the region potentially favoring the ocasional development of streamers from the US Virgin Islands, Vieques, Culebra and El Yunque rainforest. Low-to-moderate concentrations of Saharan Dust will filter by Friday onwards bringing PWAT (Precipitable Water) values down to 1.2 inches during the weekend. Sensitive groups should remain alert as air quality may deteriorate. PWAT (Precipitable Water) values will return to seasonal levels by Monday. The potential for rain each day is expected to be focused on the northwestern side of Puerto Rico and will be driven by local effects such as sea-breeze convergence, orographic effects and diurnal heating.Besides the flooding risk, visitors and citizens should experience periods of excessive heat threats. With humidity values ranging around seasonal levels and 925mb temperatures being 2 standard deviations above the normal values, the extreme heat risk remains elevated through Sunday across coastal, urban, and exposed areas, with conditions expected to vary with cloud coverage. This level of heat affects anyone without effective cooling and/or adequate hydration. With impacts likely in some health systems, heat sensitive industries and infrastructure. It is recommended that individuals limit outdoor activities and remain hydrated. It is recommended that individuals follow the instructions of health officials and monitor the evolving weather conditions. Marine Issued at 210pm AST Tuesday September 22 2026 A mid- to upper-level trough will promote an unstable weather pattern during the next few days, particularly during the afternoon and evening hours. A tropical wave arriving late Wednesday night into Thursday will prolong unsettled conditions. Moderate east to east-southeast winds will maintain choppy seas, while a low-energy northeasterly swell spreads across the local waters late Wednesday night through the end of the workweek. Beach Forecast Issued at 210pm AST Tuesday September 22 2026 A low risk of rip currents is expected across most beaches of Puerto Rico and the U.S. Virgin Islands through at least Wednesday afternoon. However, life-threatening rip currents remain possible near groins, jetties, reefs, and piers. Always swim near a lifeguard and follow beach-patrol guidance and posted flag warnings. A small northeasterly swell will likely increase the rip-current risk to moderate along north- and east-facing beaches late Wednesday night through the end of the workweek, possibly continuing into the weekend. Beachgoers should also remain weather-ready, as thunderstorms may develop each afternoon. If thunder is heard, leave the beach and seek safe shelter immediately. .SJU WATCHES/WARNINGS/ADVISORIES... PR...None. VI...None. AM...None. |
San Juan Radar
Southeast Radar