AFDSJU Area Forecast Discussion National Weather Service San Juan PR 301 PM AST Thu Dec 11 2025 ...New SHORT TERM, LONG TERM, AVIATION, MARINE, BEACH FORECAST... .KEY MESSAGES... Issued at 259 PM AST Thu Dec 11 2025 * Choppy to rough seas and life-threatening rip currents are expected to continue through the weekend. * Breezy to locally windy conditions are expected across the islands, particularly from Friday through Sunday. * For Puerto Rico, passing showers are expected mainly during the night/early morning hours across the eastern sections, followed by limited afternoon shower activity over the northwest. * For the U.S. Virgin Islands, expect isolated showers tonight into Friday morning. && .Short Term(This evening through Saturday)... Issued at 259 PM AST Thu Dec 11 2025 Generally fair weather under breezy to locally windy southeasterly flow prevailed over the islands. These brought shower activity towards windward sectors; current radar imagery detects shower activity moving over east-southeast PR, with additional showers at or in the vicinity of the USVI, Vieques and Culebra. Coastal highs reached the mid to upper 80s, with localized stations reaching the low 90s. Meanwhile, highs across higher elevations of Puerto Rico remained in the 70s. Several coastal official and unofficial stations report sustained winds between around 13-20 mph with higher gusts. Luis Munoz Marin, Cyril E. King and Henry E. Rohlsen Int. Airports have reported winds/gusts of 20g25, 20g28 and 20g27 mph, respectively. A surface high pressure over the central to eastern Atlantic will continue to promote a southeasterly steering flow during the period. This steering flow will continue to drag patches of moisture and drier air towards the region. Current Satellite Derived Precipitable Water (PWAT) values indicate a patch of more humid air (PWAT values up to around 1.75 in) over the east to southeastern region related to a disturbance. Current model guidance indicates that this patch will continue to move over the islands tonight before a patch of drier air (PWAT values around 0.95 in) reaches the area tomorrow morning. Patches of more humid air will become more frequent tomorrow morning onwards, with the most notable one (PWAT values near 2 in), another disturbance, arriving by late Saturday morning and into the long term period. These patches of moisture will promote an increase in shower activity over windward sectors, while afternoon showers over northeastern PR remains possible each afternoon. A mid level ridge northeast of the region will serve to limit shower development, however isolated areas can experience ponding of water over roadways and poorly drained areas. This southeasterly flow will result in normal to above normal 925 mb temperatures and up to breezy to locally windy conditions (15 to 25 mph with higher gusts up to 35 mph), especially on Saturday.&& .Long Term(Sunday through next Wednesday)... Issued at 442 AM AST Thu Dec 11 2025 A broad surface high pressure will linger near and south of the Azores through the long term period. Meanwhile, a cold front is expected to move early in the workweek over the western Atlantic. This surface pattern will promote southeasterly winds over the local area, leading to warmer than normal daytime temperatures across the islands. Max temps are forecast to range from the upper 80s to low 90s in some of the lower elevations, with heat indices reaching the low 100s, particularly in western PR. In terms of weather conditions, a similar weather pattern is expected early in the period due to the influence of a mid-to upper-level ridge to the east/northeast of the region. This will promote fairly stable conditions, with brief patches of moisture embedded in the trades bringing passing showers across the USVI and eastern portions of PR during the night. Shallow afternoon convection is still expected to develop over NW PR, but rainfall accumulations are not expected to cause flooding concerns. However, by midweek, an upper level trough will bring SW winds aloft, and cause a brief weakness at the surface that will allow for better pooling of moisture over the area as weak surface troughs move from east to west. This will increase the chance of showers between 40-60% each day across the islands, with a slight chance of thunderstorm development over west/northwest PR late in the afternoon hours. && .AVIATION... (18Z TAFS) Issued at 259 PM AST Thu Dec 11 2025 VFR conds are expected to prevail this forecast period. Overall E to SE winds flow through 11/23Z around 10 to 12 kts and gust up to 22 kts. Overnight, lighter winds and VCSH brfly promoting MVFR conds across USVI TAF sites and TJSJ. By 12/14Z, expect winds from the SE btwn 12-15 kt with gusts up to 25 kts. && .MARINE... Issued at 259 PM AST Thu Dec 11 2025 A surface high pressure will continue to build near the Azores through the weekend. A weak cold front and another surface high pressure will move from the western Atlantic into the central Atlantic during the next few days. This will promote moderate to locally fresh east to southeast trades across the local waters. Increasing winds and a long period northerly swell will cause choppy to rough seas, mostly over the offshore Atlantic waters. A Small Craft Advisory (SCA) is in effect for the offshore Atlantic waters through at least 6 PM AST Friday. Conditions will be hazardous to small craft. Inexperienced mariners, especially those operating smaller vessels, should avoid navigating in hazardous conditions. SCA conditions could spread towards sectors of the Anegada and Caribbean waters later this weekend. && .BEACH FORECAST... Issued at 259 PM AST Thu Dec 11 2025 There is a High Risk of Rip Currents (life-threatening rip currents are likely in the surf zone) through 6 AM Saturday the for the northwestern to northeastern beaches of Puerto Rico, as well as for Culebra and, starting at 6 PM AST this evening, St. Thomas and St. John. Factors that are deteriorating coastal conditions include a long period northerly swell and increasing wind waves. These will promote life-threatening rip currents along the north and east facing beaches of the islands during the next couple of days. Other coastal areas will have up to a moderate risk of rip currents (life- threatening rip currents are possible in the surf zone). For additional information, visit weather.gov/beach. && .SJU WATCHES/WARNINGS/ADVISORIES... PR...High Rip Current Risk through late Friday night for PRZ001-002- 005-008-012. VI...High Rip Current Risk from 6 PM AST this evening through late Friday night for VIZ001. AM...Small Craft Advisory until 6 PM AST Friday for AMZ711. && $$