AFDSJU Area Forecast Discussion National Weather Service San Juan PR 513 AM AST Sun Jan 11 2026 ...New SHORT TERM, LONG TERM, AVIATION, MARINE, BEACH FORECAST... .KEY MESSAGES... Issued at 500 AM AST Sun Jan 11 2026 * A moderate risk of rip currents continues along the north facing beaches of Puerto Rico and Culebra today. * A typical trade-wind pattern will bring passing showers to windward areas of Puerto Rico and the U.S. Virgin Islands, mainly overnight and early in the morning, with afternoon showers, especially across southwestern Puerto Rico. Localized ponding or minor flooding is possible in poor drainage areas of Puerto Rico and the U.S. Virgin Islands. * Near-seasonal temperatures will continue across Puerto Rico and the U.S. Virgin Islands, with comfortable daytime temperatures for outdoor activities through around mid-week, then guidance indicates above-normal temperatures for end of the week. && .Short Term(Today through Tuesday)... Issued at 500 AM AST Sun Jan 11 2026 Southern and western Puerto Rico, as well as St. Croix, observed mostly clear skies with pleasant temperatures. In contrast, the northern U.S. Virgin Islands and the north and east Puerto Rico experienced occasional fast-moving showers, producing periods of moderate to locally heavy rainfall overnight. Minimum temperatures ranged from the low 70s across coastal areas to the low 60s, and locally lower, across interior valleys and mountainous regions. Winds were generally from the northeast at around 5 mph, with localized land-breeze variations. A mid- to upper-level trough continues to move eastward away from the northeastern Caribbean into the Atlantic, periodically perturbing the trade wind flow. These perturbations will support intermittent moisture surges, resulting in passing showers across windward areas of Puerto Rico and the U.S. Virgin Islands over the next few days. Meanwhile, a surface high pressure north of the region will shift farther east as a weak, surface-induced trough moves through the local area. This pattern will allow low-level winds to veer slightly more easterly at times; however, a prevailing northeasterly steering flow is expected to persist. Under this synoptic setup, a typical trade-wind advective pattern is anticipated today through Tuesday. Evening and morning showers will mainly affect windward and coastal areas, followed by afternoon convection driven by local effects, primarily across western Puerto Rico each day, where we cannot rule out one or two thunderstorms. Rainfall impacts are expected to remain limited overall, though brief periods of moderate to locally heavy rainfall are possible with passing showers, particularly along windward locations. Across western Puerto Rico, localized ponding of water on roads and in poorly drained areas may occur during afternoon convection. While widespread flooding is not anticipated, isolated urban flooding cannot be ruled out. && .Long Term(Wednesday through Sunday)... Issued at 500 AM AST Sun Jan 11 2026 During the long-term period, a deep-layer mid to upper-level trough will continue shifting eastward away from the Lesser Antilles, while a weak mid to upper-level ridge builds over the northeastern Caribbean. Precipitable water values are forecast to range between 1.4 and 1.9 inches, near to above climatological normal for this time of year, with peak moisture expected on Friday. Low-level winds will generally remain from the east to southeast through Friday, then shift to the east-northeast on Saturday and Sunday while increasing in speed. Model guidance suggests a frontal boundary will remain north of the region, while a pre- frontal trough may enhance moisture convergence and atmospheric instability, supporting a wetter pattern around Friday and again next Saturday. At this time, Friday appears to present the highest rainfall potential, with a limited flood risk mainly across western Puerto Rico during the afternoon hours. Isolated thunderstorm activity cannot be ruled out as mid-level temperatures cool, with 500 mb temperatures decreasing from near -5 degrees C on Wednesday to around -8 degrees C by the end of the week. Ensemble guidance continues to indicate above-normal temperatures across Puerto Rico and the U.S. Virgin Islands throughout the long-term period. && .AVIATION... (06Z TAFS) Issued at 500 AM AST Sun Jan 11 2026 VFR conditions will prevail today. However, occasional -SHRA/SHRA will move across JSJ/IST/ISX throughout the day, followed by some activity near JPS during the afternoon. This activity will bring brief MVFR conditions at these sites. We cannot rule out one or two TSRA/-TSRA across the interior and SW-PR between 11/16-23z. A similar weather pattern is possible for tomorrow. Winds will be calm to light and variable each night, returning from the NE/E at 10-15kt with higher gusts, and a sea breeze aft 13z. && .MARINE... Issued at 500 AM AST Sun Jan 11 2026 A surface high pressure moving eastward across the western Atlantic, combined with a weak surface trough northeast of the region, will maintain moderate east to northeast winds across the local waters through the middle of next week. This pattern will support passing trade-wind showers, mainly across the Atlantic waters, with occasional showers also moving through the Caribbean passages at times. Wind flow becoming east to southeast around Thursday and Friday. Toward the latter part of the workweek and into the weekend, strengthening winds and the arrival of a long-period northerly swell may result in choppy and potentially hazardous marine conditions. Mariners are advised to continue monitoring the forecast. && .BEACH FORECAST... Issued at 500 AM AST Sun Jan 11 2026 Today, a moderate risk of rip currents is in place for the northern and eastern beaches of Puerto Rico, as well as Culebra, with breaking waves around 4 feet. Similar conditions are expected to persist over the next few days, with the moderate risk at times extending to the northwestern beaches of Puerto Rico and the U.S. Virgin Islands. A moderate risk indicates that life- threatening rip currents are possible within the surf zone. A low risk will prevail across southern, more protected areas; however, life-threatening rip currents can still occur near groins, jetties, reefs, and piers even when the overall risk is low. For more location-specific information, continue to monitor weather.gov/beach/sju. By next weekend, conditions may deteriorate, with the potential for a high risk of rip currents to return. && .SJU WATCHES/WARNINGS/ADVISORIES... PR...None. VI...None. AM...None. && $$