Leeward Islands Offshore Forecast
| Tonight...E Winds 15 To 20 Kt. Seas 5 To 7 Ft. |
| Mon...E Winds 15 To 20 Kt. Seas 6 To 8 Ft In E Swell. |
| Mon Night...Ne To E Winds 15 To 20 Kt. Seas 6 To 8 Ft In E Swell. |
| Tue...E Winds 15 To 20 Kt. Seas 6 To 8 Ft In E Swell. |
| Tue Night...E Winds 15 To 20 Kt. Seas 6 To 8 Ft In E Swell. |
| Wed...E Winds 15 To 20 Kt. Seas 6 To 8 Ft In E Swell. |
| Wed Night...E Winds 15 To 20 Kt. Seas 6 To 8 Ft In E To Se Swell. |
| Thu...E Winds 15 To 20 Kt. Seas 6 To 8 Ft In E To Se Swell. |
| Thu Night...E Winds 15 To 20 Kt. Seas 5 To 7 Ft In E To Se Swell. |
| Fri...Ne To E Winds 10 To 15 Kt. Seas 5 To 7 Ft In E To Se Swell. |
| Fri Night...Ne To E Winds 10 To 15 Kt. Seas 4 To 6 Ft. |
| Area Forecast Discussion National Weather Service San Juan PR 110pm AST Sunday Jun 21 2026 .Short Term(This evening through Tuesday)... Issued at 1256pm AST Sunday Jun 21 2026 A passing tropical wave promoted shower activity during the morning hours across portions of eastern and northeastern Puerto Rico. As the day progressed, these showers spread along the northern coast, while convective activity intensified across western Puerto Rico. Doppler radar estimated rainfall accumulations between 1.0 and 2.0 inches by early afternoon. Meanwhile, mainly fair weather prevailed across the U.S. Virgin Islands, which saw few clouds and no significant rainfall. Maximum temperatures reached the upper 80s to low 90s across lower elevations, and the low-to-mid 80s in the higher mountains. Winds blew from the east at 15 to 20 mph, with local sea breeze variations and higher gusts reaching around 30 mph, particularly along coastal areas. Showers and a few isolated thunderstorms will continue to develop through the afternoon hours across central and western Puerto Rico, bringing additional accumulations of 1 to 2 inches. However, by later this afternoon, the tropical wave is expected to move westward, eventually exiting the region tonight into early Monday. By Monday, a drier airmass will filter into the area alongside moderate concentrations of Saharan dust. This will result in hazy skies, reduced visibility, and poor air quality. Sensitive groups, particularly individuals with respiratory conditions, should take the necessary precautions to limit outdoor exposure and follow medical guidance. By Tuesday, similar conditions will prevail as a mid-level ridge strengthens over the region, promoting drier and more stable conditions aloft. At the upper levels, a low-pressure system located north of the northeast Caribbean will continue migrating northward, losing its influence over the local area. While another low-pressure system is forecast to build over the Caribbean Sea, it will have little impact on local weather. Overall, passing trade-wind showers will continue to affect windward and eastern areas of Puerto Rico and the U.S. Virgin Islands during the morning hours, while the rest of the region remains on the drier side. Afternoon convection remains possible across western and central Puerto Rico, driven by daytime heating and local effects. Seasonably warm temperatures will persist, with highs reaching the upper 80s to low 90s across coastal and urban locations, and from the low to mid 80s in the mountains. .Long Term(Wednesday through next Saturday)... Issued at 1256pm AST Sunday Jun 21 2026 A tropical wave is forecast to move across the region on Wednesday and Thursday. While the wave will bring an increase in low-level moisture and result in a higher frequency of passing showers, model guidance suggests precipitable water values will remain near seasonal levels. In addition, mid-level relative humidity is expected to remain relatively low, while temperatures near 500 mb stay close to normal, limiting the potential for widespread deep convection. As a result, periods of passing showers are expected, particularly across windward and eastern sections during the morning hours and across western Puerto Rico during the afternoon due to local effects. However, significant rainfall accumulations are not anticipated at this time. Dust aerosol model guidance suggests that low to moderate concentrations of Saharan dust may reach the local islands by Thursday. The arrival of this dust could promote hazy skies and occasionally reduced visibility while also contributing to a more stable atmosphere. Although the tropical wave is expected to enhance shower activity, the extent to which rainfall associated with the wave offsets the effects of the dust remains somewhat uncertain. Therefore, residents and visitors are encouraged to continue monitoring the latest forecasts for updates regarding both rainfall potential and air quality conditions. At this time, the highest concentrations of Saharan dust will Friday. Therfore, those with respiratory conditions are urged to follow the health experts recommendations and avoid outdoor activities. By Friday and continuing through Saturday, moisture levels are expected to remain near to slightly below seasonal normals while relatively dry mid-level air persists across the region. This should support a decrease in shower coverage and a return to a more typical trade-wind weather pattern. Nevertheless, patches of shallow moisture embedded within the trades may still result in brief passing showers across windward areas from time to time. Temperatures will continue near seasonal normals. While no significant weather impacts are anticipated through the end of the forecast period, those planning outdoor activities should remain aware of passing showers and any lingering hazy conditions that could produce localized visibility reductions. Marine Issued at 1256pm AST Sunday Jun 21 2026 A tropical wave moving across the Caribbean will continue to support showers and isolated thunderstorms over the local waters through late tonight. Meanwhile, a broad surface high pressure system over the central Atlantic will maintain moderate to locally fresh easterly to east-southeasterly winds through the next several days, resulting in choppy seas across the local waters and Caribbean passages. Small craft should exercise caution. In addition, moderate to occasionally high concentrations of Saharan dust will persist into early next week, producing hazy skies, reduced visibility, and poor air quality. Beach Forecast Issued at 1256pm AST Sunday Jun 21 2026 A moderate risk of rip currents remains in effect for most local beaches, including northern and eastern Puerto Rico, Vieques, Culebra, and portions of the U.S. Virgin Islands, while a low risk persists for the south-central and western coasts of Puerto Rico and the northern U.S. Virgin Islands. Life-threatening rip currents remain possible. Scattered showers and isolated thunderstorms associated with a tropical wave will continue across portions of the local waters and islands tonight before gradually diminishing on Monday. Meanwhile, moderate to high concentrations of Saharan dust will persist across the region through early next week, resulting in hazy skies, reduced visibility, and poor air quality. .SJU WATCHES/WARNINGS/ADVISORIES... PR...None. VI...None. AM...None. |