AFDSJU Area Forecast Discussion National Weather Service San Juan PR 1256 PM AST Thu Jan 8 2026 ...New SHORT TERM, AVIATION, MARINE, BEACH FORECAST... .KEY MESSAGES... Issued at 1205 PM AST Thu Jan 8 2026 * An increase in the potential for shower activity is forecast for this afternoon along the interior and western sections of PR. * Life-threatening rip currents will remain through 6 PM today along the north and east-facing beaches of Puerto Rico as a persistent northeasterly swell across the local Atlantic waters prevails. A moderate risk will continue for north and east- facing beaches of the U.S. Virgin Islands after 6 PM. * Seasonal temperatures will prevail across the islands through the next several days, with cooler conditions continuing in the higher elevations. && .Short Term(This evening through Saturday)... Issued at 1205 PM AST Thu Jan 8 2026 Clear to partly cloudy skies prevailed across the islands this morning, with brief passing showers mainly affecting eastern and northeastern Puerto Rico. Conditions remained seasonable, with light northeast winds and limited moisture. Weather conditions from this evening through Saturday will remain governed by a weak and persistent pattern, with no major synoptic changes anticipated. A weak surface trough lingering northeast of the region, along with subtle troughing aloft, will continue to promote shallow shower activity embedded within the trade wind flow. Precipitable water values will remain near to slightly below seasonal levels, generally around 1.2 to 1.4 inches. For this afternoon into early evening, ensemble guidance indicates the highest rainfall potential across interior and western to southwestern Puerto Rico, where localized amounts near or slightly above one inch are possible due to daytime heating and sea-breeze convergence in combination with sufficient low-level moisture. This evening and overnight, shower activity will gradually diminish over western areas and transition back to brief trade wind showers affecting eastern Puerto Rico and the U.S. Virgin Islands. On Friday and Saturday, a similar pattern will persist. Morning hours will favor passing showers across windward areas, followed by isolated to scattered afternoon showers over interior and western Puerto Rico driven by daytime heating and local effects. Temperatures will remain near climatological normals throughout the period. The 925 mb temperatures support seasonable daytime highs across coastal areas, with cooler conditions continuing across higher elevations during the overnight and early morning hours. Overall, the short-term period will feature generally fair and seasonable weather, punctuated by brief passing showers and localized afternoon convection, with the greatest rainfall potential confined to interior and western Puerto Rico this afternoon and again during peak heating periods through Saturday. && .Long Term(Sunday through next Wednesday)... Issued at 403 AM AST Thu Jan 8 2026 Surface high pressure over the north-central Atlantic will promote moderate to locally fresh east-northeast winds through late Tuesday night. From Wednesday onward, winds are expected to shift from the east as the high pressure migrates toward the eastern Atlantic. At the mid-to-upper levels, a ridge will build over the southwestern Atlantic while a Tropical Upper Tropospheric Trough (TUTT) begins to develop over the central Atlantic, northeast of the Lesser Antilles. The latest model guidance continues to suggest precipitable water (PWAT) values will remain near normal on Sunday before dropping below seasonal averages by Monday (0.85 to 1.21 inches). Despite the strength of the TUTT low to the northeast, dry air intrusion associated with the mid-to-upper level ridge will promote stable conditions aloft. This will inhibit shower development across Puerto Rico and the U.S. Virgin Islands throughout the period. Temperatures at the 925 mb level will remain near seasonal averages. Consequently, expect maximum temperatures in the low to mid-80s across lower elevations and in the mid to upper 70s across higher terrain. && .AVIATION... (18Z TAFS) Issued at 1205 PM AST Thu Jan 8 2026 Mainly VFR conditions expected across all terminals. Brief VCSH/SHRA possible this afternoon into early evening, mainly across TJPS, with isolated MVFR in heavier showers. Activity diminishes after sunset. E-ENE winds 5-12 kt, locally gusty during the afternoon with sea breeze variations, becoming lighter overnight and increasing again aft 09/13z. && .MARINE... Issued at 1205 PM AST Thu Jan 8 2026 The long-period northeasterly swell will continue to spread across the Atlantic waters and local Caribbean passages through this evening. A surface high pressure over the western Atlantic, along with weak induced surface troughs northeast of the region, will promote moderate east to northeast trade winds through the the rest of the week. && .BEACH FORECAST... Issued at 1205 PM AST Thu Jan 8 2026 Hazardous coastal conditions will continue across the local beaches through at least this afternoon due to a spreading northeasterly swell affecting the Atlantic waters. This swell will maintain life- threatening rip current conditions along the northwest to northeast-facing beaches of Puerto Rico, where a High Rip Current Risk remains in effect until 6 PM AST today. Life- threatening rip currents are possible along north and east- facing beaches of the U.S. Virgin Islands, where a moderate rip current risk is expected. && .SJU WATCHES/WARNINGS/ADVISORIES... PR...High Rip Current Risk until 6 PM AST this evening for PRZ001-002- 005-008. VI...None. AM...None. && $$