AFDSJU Area Forecast Discussion National Weather Service San Juan PR 246 PM AST Sat Jan 10 2026 ...New SHORT TERM, LONG TERM, AVIATION, MARINE, BEACH FORECAST... .KEY MESSAGES... Issued at 246 PM AST Sat Jan 10 2026 * A moderate risk of rip currents continues along Atlantic-facing beaches of Puerto Rico, with the risk possibly extending to western Puerto Rico, Culebra, and the U.S. Virgin Islands on Sunday. Dangerous swimming conditions are possible at exposed beaches across Puerto Rico and the U.S. Virgin Islands. * 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 limited afternoon showers, especially across southwestern Puerto Rico. Rainfall will generally be light, though localized ponding or minor flooding is possible in poor drainage areas of Puerto Rico and the U.S. Virgin Islands. Widespread flooding is not expected. * Cooler-than-normal nighttime temperatures will continue across Puerto Rico and the U.S. Virgin Islands, with comfortable, near- seasonal daytime temperatures and generally favorable conditions for outdoor activities across the islands.. && .Short Term(This evening through Monday)... Issued at 246 PM AST Sat Jan 10 2026 Cloudy conditions developed early across windward areas as trade- wind showers moved onshore, followed by localized afternoon showers over southwestern Puerto Rico, steered by a persistent northeasterly flow. No flooding was reported. Cooler temperatures prevailed across higher elevations, with lows in the low 60s and highs in the low 70s, while coastal and interior urban areas were warmer, with maximum temperatures reaching the mid to upper 80s. At San Juan International Airport, temperatures ranged from 73F to 84F. Rainfall totals reached up to 1.5 inches in parts of southwestern Puerto Rico since midday, with isolated amounts near one-half inch across windward areas since midnight. Winds were light and variable early, increasing to east-northeast at 1015 mph with sea-breeze variations. A surface high well to the north will maintain the overall northeasterly flow, allowing cooler air and shallow moisture to move into the region. While cooler air aloft associated with an upper-level trough is present, dry mid- levels will keep moisture shallow and capped, limiting convection from growing deep enough to support thunderstorm development. Still, this pattern will favor passing trade-wind showers, mainly affecting windward areas of the U.S. Virgin Islands, Vieques, Culebra, and northern and eastern Puerto Rico, especially late tonight and early in the morning. Rainfall will be brief and light, with no flooding expected, and outdoor activities may be briefly affected. Minimum temperatures are expected to drop below those observed today as cooler air sinks farther south and winds become light and variable, particularly across interior and higher-elevation areas. Fog development is likely in cloud-free locations, mainly in valleys and higher terrain. As a surface high to the north shifts farther east and a weak, surface-induced trough moves through the region, low-level winds will veer slightly more easterly at times, but the overall northeasterly steering flow will persist. This pattern will continue to support passing trade-wind showers, mainly during the overnight and early-morning hours across windward areas. During the afternoon, local heating will help initiate showers, and the persistent northeasterly flow will push activity toward western and southwestern Puerto Rico, where low-level convergence against the sea breeze will be strongest. Rainfall will generally be light and brief, though an isolated heavier shower could cause minor ponding in low-lying or poor-drainage areas; widespread flooding is not expected. Cooler-than-normal and comfortable temperatures will continue through Sunday and Monday, with cool nights and generally favorable conditions for outdoor activities, aside from brief interruptions from passing showers. && .Long Term(Tuesday through next Friday)... Issued at 420 AM AST Sat Jan 10 2026 A deep-layer mid-to-upper-level trough will continue moving eastward and away from the Lesser Antilles from Tuesday onward. At the same time, a mid-to-upper-level ridge builds over the Northeast Caribbean. At the surface, an abnormally strong Azores High will persist over the North Atlantic. This pattern will keep frontal boundaries exiting the eastern seaboard well north of Puerto Rico and the US Virgin Islands, limiting any direct frontal influence over the local area through at least the end of the upcoming workweek. Then, ECMWF and GFS indicated a frontal boundary approaching the region. If it gets close enough, it could promote increased available moisture and the potential for an unstable wet pattern around Friday and next Saturday. Under this configuration, the prevailing weather will be dominated by a typical trade-wind (advective) pattern. This will favor occasional periods of passing showers, mainly affecting windward locations of Puerto Rico and the US Virgin Islands, including the eastern and northeastern coastal areas. These showers are expected to be brief, with limited rainfall accumulation. As the mid-to upper-level ridge strengthens, atmospheric stability is expected to increase. This will result in reduced afternoon convection over western Puerto Rico, compared to more unsettled patterns. Any afternoon showers that do develop are expected to be isolated and short-lived. Ensemble model guidance indicates that temperatures over the long term will range from near-normal to slightly above-normal across Puerto Rico and the US Virgin Islands. && .AVIATION... (18Z TAFS) Issued at 246 PM AST Sat Jan 10 2026 Mainly VFR conds expected at all TAF sites. Brief VCSH/SHRA will continue as trade-wind SHRA move inland over the next 1218 hrs, with locally induced SHRA mainly affecting southern terminals, potentially causing brief MVFR cigs at TJPS thru ~10/21Z. SHRA coverage will decrease after 11/14Z, becoming isolated and mainly confined to northern terminals. Sfc winds ENE 1014 kt, becoming lgt/vrb (<6 kt) after 10/22Z, then incr to 1015 kt with sea- breeze var aft 11/13Z. && .MARINE... Issued at 246 PM AST Sat Jan 10 2026 Surface high pressure migrating eastward across the western Atlantic, in combination with a weak surface-induced 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. Overall marine conditions are expected to remain generally favorable, though brief reductions in visibility are possible in heavier showers. && .BEACH FORECAST... Issued at 246 PM AST Sat Jan 10 2026 A moderate risk of rip currents will continue along north-facing beaches of Puerto Rico, as well as Culebra and portions of the U.S. Virgin Islands. While the risk is not expected to increase, dangerous rip currents will remain possible, particularly along exposed beaches. Beachgoers are urged to exercise caution, stay near lifeguarded beaches when available, and avoid entering the water if conditions appear unsafe. && .SJU WATCHES/WARNINGS/ADVISORIES... PR...None. VI...None. AM...None. && $$