AFDSJU Area Forecast Discussion National Weather Service San Juan PR 229 PM AST Thu Apr 2 2026 ...New SHORT TERM, LONG TERM, AVIATION, MARINE, BEACH FORECAST... .KEY MESSAGES... Issued at 222 PM AST Thu Apr 2 2026 * Life-threatening rip currents will continue at north- and east-facing beaches through early next week. While dangerous surf is expected to gradually subside after this evening, conditions will remain hazardous. It is advised to stay out of the water in high- risk areas. * Hazardous seas will persist through early next week, making conditions unfavorable for small craft in local waters. * Expect showers and isolated thunderstorms each afternoon, becoming more widespread and stronger over the weekend. A Limited to Elevated Flooding Risk will persist, along with the threat of lightning and gusty winds. * Breezy to locally windy conditions will continue, with stronger gusts possible in exposed areas and near showers. && .Short Term(This evening through Saturday)... Issued at 222 PM AST Thu Apr 2 2026 Variable conditions persisted during the morning hours, with passing showers moving across the regional waters into portions of northern and eastern PR and the U.S. Virgin Islands. Based on the WSR-88D rainfall estimates, some areas have received up to 1 inch during the morning. Winds from the northeast strengthen, with CWOP/ASOS stations reporting maximum wind gusts of up to 25 mph across the islands, locally higher in areas such as the Luis Munoz Marin International Airport, where a gust of 32 mph was reported. Taking a look at the 12z RAOB, PWAT values (1.44 inches) remain near the mean values (1.54 inches) for this time of the year, showing most of the moisture content in the low levels (83 %). Additionally, cooler than normal mid-level temperatures (500 mb temperatures around -8 degrees Celsius) and strong winds aloft (250 mb winds around 90 knots) should allow cloud growth and ventilation, leading to the development of thunderstorms. Afternoon convection is currently affecting interior, south and southwestern portions of Puerto Rico. Accumulations should remain up to 2 inches, though isolated areas may reach 3 inches. Due to previous rainfall activity across these areas and above normal streamflows, the potential of flooding will remain elevated. As of 2:05 PM AST, Flood Advisories are in effect for Cabo Rojo, Hormigueros, Lajas, San German, Ponce, Penuelas until 4 PM AST. A variable weather pattern will persist in the short term forecast. Satellite-derived products show abundant moisture content reaching the CWA, pooled from the deep-layered trough and induced surface trough northeast of the Leeward Islands. A surface high pressure over the north central Atlantic combined with the surface trough will keep promoting a northeasterly wind flow, transitioning from the east-southeast by Saturday. For tonight and early Friday, passing showers will likely move across northern and eastern portions of Puerto Rico and the U.S. Virgin Islands, though rainfall accumulation will likely remain limited. Friday afternoon will likely be similar to today, with showers and isolated thunderstorms moving over interior into southwestern portions of Puerto Rico. Ponding of water over roadways and poorly drained areas is likely, including minor flooding. As the deep layered trough migrates eastward, a mid to upper level low will move near Cuba and the Bahamas by late Friday night, bringing a jet streak over the CWA, with winds between 80 to 90 knots. The deterministic guidance of the GFS and ECMWF show abundant moisture pooling into the region, reaching above normal values for this time of the year. From the latest solutions, ensemble members are tending to wetter conditions, with PWAT values between 1.8 and 2.0 inches. Nevertheless, the latest average simulated IR show cloud coverage associated to the mid to upper level low that may move over the CWA on Saturday, inhibiting afternoon convection. Additionally, strengthening winds may promote more progressive showers instead of stationary. Hence, the most likely scenario would be an increment of showers moving over windward sections throughout the day, while the afternoon convection will rely on cloud cover. At the moment, the flooding potential will remain limited to elevated for most portions of Puerto Rico, particularly over interior and northwestern Puerto Rico and the San Juan Metropolitan Area. Breezy to locally windy conditions will continue across coastal areas of the islands, with winds between 15 to 25 mph and gusts up to 30 - 35 mph. && .Long Term(Sunday through next Wednesday)... Issued at 225 AM AST Thu Apr 2 2026 A warmer and more humid pattern will support increasing afternoon convection and a rising flood risk through midweek. By Sunday onward, the surface pattern will be dominated by high pressure migrating eastward into the Atlantic, promoting a shift in low-level winds from easterly to southeasterly, which will persist through most of the period. A mid- to upper-level shortwave trough will induce a surface trough northwest of the region, supporting continued advection and pooling of tropical moisture into the area. Based on the latest guidance, precipitable water values are forecast to slightly decrease on Sunday but remain near to above normal for this time of year, around 1.6 to 1.7 inches. From Monday through Wednesday, as the induced disturbance drifts northward, increasing low-level moisture from the Caribbean will spread across the islands, with precipitable water values rising to around 1.9 to 2.0 inches. Given this pattern and the latest model guidance, the heaviest rainfall is expected to remain north of the region over the Atlantic waters. However, scattered passing showers will affect the waters, the U.S. Virgin Islands, and windward sections of Puerto Rico during the overnight and early morning hours, followed by more widespread and better-organized afternoon convection across interior and northwestern Puerto Rico. Local effects will enhance shower and thunderstorm development each day. This pattern, combined with warm and humid conditions, will increase the risk of urban and small stream flooding, with flood risk ranging from limited to elevated. Temperatures are expected to trend warmer at the beginning of the long-term period, with 925 mb values approaching the 75th percentile, or about two standard deviations above normal. This will further support instability and convective potential each afternoon. && .AVIATION... (18Z TAFS) Issued at 222 PM AST Thu Apr 2 2026 Mainly VFR conds expctd across most TAF sites, except JPS during this aftn due to -TSRA, reducing CIGs/VIS and leading to MVFR conds. VCSH will persist across northern and eastern TAF sites aft 02/23z. Winds will weaken and become light and VRB, strengthening btwn 15 and 18 kt, with higher gusts aft 03/12z. VCTS cannot be ruled out for JPS by 03/17z. && .MARINE... Issued at 222 PM AST Thu Apr 2 2026 Hazardous marine conditions are likely to persist during the weekend and into next week. A strong surface high pressure system over the Atlantic will promote fresh to locally strong northeasterly winds. These winds will gradually veer to become more easterly late Friday and east-southeasterly Saturday into Sunday. Pulses of northeasterly swell and the above mentioned winds will maintain choppy to rough seas across the regional waters, mainly over the Atlantic and local passages. Frequent trade wind showers will continue to move over the local waters, while isolated to scattered afternoon thunderstorms may develop over the coastal waters, especially from the southwest to northwest of Puerto Rico, drifting west-northwest with the prevailing flow, with a slight increase in coverage over the weekend. && .BEACH FORECAST... Issued at 222 PM AST Thu Apr 2 2026 A High Surf Advisory is in effect for the north-west northern and eastern coastlines for Puerto Rico, Vieques, Culebra and the U.S. Virgin Islands through this evening. Pulses of northeasterly swell and fresh to strong winds will result in a High Risk of Rip Currents along those areas through at least early next week. Beachgoers and inexperienced surfers are strongly urged to stay out of the water. Avoid walking along rocks or jetties, as large breaking waves can sweep individuals into the sea without warning. Always heed the advice of lifeguards and follow posted beach flags and signs. Access to hazardous beaches may be limited, and individuals should follow all posted warnings and safety guidance. Visitors should also be mindful of the weather, in addition to surf hazards. Like today, isolated thunderstorms and showers are possible each afternoon, especially over W-SW Puerto Rico tomorrow and W-NW Puerto Rico during the weekend. These storms may generate dangerous lightning, so if thunder is heard, immediately seek refuge inside a sturdy building. && .SJU WATCHES/WARNINGS/ADVISORIES... PR...High Rip Current Risk through Sunday afternoon for PRZ001-002- 005-008-010-012-013. High Surf Advisory until 6 PM AST this evening for PRZ001-002- 005-008-010-012-013. VI...High Rip Current Risk through Sunday afternoon for VIZ001-002. High Surf Advisory until 6 PM AST this evening for VIZ001-002. AM...Small Craft Advisory until 6 PM AST Sunday for AMZ711-712-716- 723-741. Small Craft Advisory until 6 AM AST Friday for AMZ726-742. && $$