AFDSJU Area Forecast Discussion...CORRECTED National Weather Service San Juan PR 350 PM AST Tue Mar 31 2026 ...New SHORT TERM, AVIATION, MARINE, BEACH FORECAST... .KEY MESSAGES... Issued at 220 PM AST Tue Mar 31 2026 * Hazardous beach conditions continue: Life-threatening rip currents and dangerous surf will persist along north- and east- facing beaches of Puerto Rico and the U.S. Virgin Islands. Avoid entering the water in these areas. * Periods of showers and isolated thunderstorms: Passing showers will affect the region overnight and during the morning, with additional afternoon showers and isolated thunderstorms mainly across western Puerto Rico. Brief heavy rain may lead to localized flooding, especially in urban areas with poor drainage. * Isolated thunderstorms possible this afternoon: Some storms may produce lightning, brief heavy rainfall, and gusty winds. * Breezy conditions persist: Breezy to locally windy conditions will continue, especially along coastal and exposed areas, allowing showers to move quickly across the region. * Impacts on daily activities: Outdoor and holiday plans may be affected by rain and hazardous marine conditions. Stay alert for changing weather conditions and follow local safety guidance. && .Short Term(This evening through Thursday)... Issued at 220 PM AST Tue Mar 31 2026 Fair weather prevailed today across the islands as a somewhat drier air mass moved across the archipelago of PR and the USVI. However, showers embedded in the trades occasionally moved inland across the windward areas. The trade winds were mainly 10 to 20 mph, with gusts up to 25 mph. Most coastal and urban sites recorded maximum temperatures in the mid- to upper 80s, while mountain sites recorded maximum temperatures in the mid-70s. Showers with the possibility of one or two thunderstorms are still possible across the interior and southwest sections through this evening. While the northeasterly winds will continue to advect patches of clouds producing showers across the windward locations of PR and the US Virgin Islands, especially from late tonight into early Wednesday morning, when low-level convergence could enhance this activity, which may lead to a limited risk of flooding. Looking ahead, northeasterly winds will continue to affect the region, with breezy to locally windy conditions through the short- term period, leading to periodic increases in moisture and rainfall across windward locations, followed by afternoon convection across the interior and southwest quadrant each day. Meanwhile, high surf conditions will lead to life-threatening rip currents along north-facing beaches of St Thomas, St John, and adjacent Islands, Puerto Rico, including Culebra and Vieques, through the rest of the short term. A long-period northerly swell will bring: High surf, Life-threatening rip currents, and Possible coastal erosion. If you plan to visit the beach, use extreme caution and consider south- or Caribbean-facing beaches, where conditions are safer. && .Long Term(Friday through Tuesday)... Issued at 230 AM AST Tue Mar 31 2026 From Friday into Saturday, an evolving pattern under the influence of an induced surface trough and a shortwave trough will enhance a more unstable weather pattern across the islands. At the surface, the induced surface trough, in combination with a surface high pressure over the Central Atlantic, will promote a northeasterly wind flow across the area, rapidly shifting to the east-southeast early Friday as the surface perturbation moves west of the region. At the upper levels, a shortwave trough will move across the region, favoring enhanced instability and thunderstorm development. This pattern will support a high chance of showers across the area; however, the forecast will be largely dependent on surface conditions at the time. According to global model guidance and relative humidity values, a deep upper-level cloud layer may inhibit the diurnal heating trigger. If sufficient heating does not develop, widespread shower activity is not anticipated; however, some well- developed showers are still expected across the northwestern section and the San Juan Metropolitan area. On Sunday, global model guidance from the GFS and ECMWF continues to suggest precipitable water values up to 1.7 inches, which remains near the 75th percentile for this time of year, consistent with relative humidity values between 850 and 500 mb. By Monday onward, the main surface weather pattern will be driven by a broad surface high pressure over the Central Atlantic, resulting in a tightening of the pressure gradient and increasing winds. Under this pattern, global model guidance suggests an increase in low- level moisture across the Caribbean moving into the local islands. The GFS indicates precipitable water values up to 1.9 inches, which remains around the 75th percentile through the rest of the period. Under this setup, reduced upper-level dynamics will limit upper- level cloudiness, allowing the diurnal heating process to become more effective. Under this scenario, afternoon convection is likely to become more widespread and better organized, particularly across western and interior Puerto Rico, where local effects will enhance shower and thunderstorm development. This increase in convective activity, combined with warm and moist conditions, will elevate the risk of urban and small stream flooding, especially in areas that experience repeated rainfall. In addition, temperatures are expected to trend above normal, with coastal highs reaching the low 90s, further supporting instability and convective potential each afternoon. && .AVIATION... (18Z TAFS) Issued at 220 PM AST Tue Mar 31 2026 VFR conds across all TAF sites. Frequent VCSH anticipated over TJSJ, TIST, and TJBQ after 30/18Z, then from 31/00Z thru 31/12Z. Today, winds will remain from NE at 8 to 12kts with occasional higher gust. Winds are forecasts increase from 31/12Z onwards to 15 - 20 kt and higher gust at times. && .MARINE... Issued at 220 PM AST Tue Mar 31 2026 Confused and hazardous seas will persist through much of the week due to fresh to strong northeasterly winds combined with a long- period northerly swell, creating dangerous conditions for small craft. Showers will move across the regional waters, especially late tonight into early Wednesday morning, as a shear line remains north of the area. A strong Atlantic high-pressure system will maintain these windy conditions through at least Friday, with winds gradually shifting to the east; however, choppy to rough seas will persist even after the wind shift. && .BEACH FORECAST... Issued at 220 PM AST Tue Mar 31 2026 Dangerous surf conditions are creating life-threatening rip currents along north-facing beaches of Puerto Rico and the U.S. Virgin Islands, where entering the water is strongly discouraged. While south-facing beaches have a lower risk, caution is still advised as conditions can change quickly. Hazardous marine conditions will persist through much of the week, with a High Surf Advisory in effect through at least late Wednesday night and a continued high risk of rip currents beyond that. Beachgoers should remain alert, follow local safety guidance, and only swim near lifeguards. && .SJU WATCHES/WARNINGS/ADVISORIES... PR...High Rip Current Risk through Friday evening for PRZ001-002-005- 008-010-012. High Surf Advisory until 6 PM AST Wednesday for PRZ001-002-005- 008-010-012-013. High Rip Current Risk through late Wednesday night for PRZ013. VI...High Rip Current Risk through Friday evening for VIZ001. High Surf Advisory until 6 PM AST Wednesday for VIZ001. AM...Small Craft Advisory until midnight AST Friday night for AMZ711- 712-716-723-741-742. Small Craft Advisory until 6 AM AST Thursday for AMZ726. && $$