AFDSJU Area Forecast Discussion National Weather Service San Juan PR 518 AM AST Thu Nov 27 2025 ...New SHORT TERM, LONG TERM, AVIATION, MARINE, BEACH FORECAST... .KEY MESSAGES... Issued at 518 AM AST Thu Nov 27 2025 * Happy Thanksgiving! Breezy conditions are anticipated today; therefore, unsecured items could blow around. * Wind-driven seas will result in choppy and hazardous marine conditions for small crafts; Small Craft Advisories are in effect. * Life-threatening rip currents will remain possible across most beaches of Puerto Rico and the U.S. Virgin Islands. * Quick moving showers will continue over windward areas of Puerto Rico and the U.S. Virgin Islands today and tonight; afternoon showers forecast today for southwestern Puerto Rico as well. && .Short Term(Today through Saturday)... Issued at 518 AM AST Thu Nov 27 2025 Partly cloudy skies prevailed overnight. As observed over the past few days, showery weather persisted across the local waters, with some showers reaching northern and eastern Puerto Rico and the vicinity of the U.S. Virgin Islands. Radar estimates indicate between 0.15 and 0.45 inches of rainfall in these areas since midnight. Minimum temperatures ranged from the low to mid-70s across coastal areas and the U.S. Virgin Islands, and into the mid-60s or slightly lower across the mountains and interior valleys of Puerto Rico. At the surface, a broad high-pressure system over the central tropical Atlantic will continue to support a moderate to fresh east- northeast wind flow through the forecast period. Aloft, lingering influence from a shortwave trough will diminish as it moves away this morning, allowing mid-level ridging to briefly develop across the region. A polar trough is then forecast to move across the western Atlantic tonight, along with its associated frontal boundary, through the short-term period. According to the latest guidance, precipitable water values will fluctuate between 1.30 and 1.65 inches, which is considered below normal to near average for this time of year. As a result, a seasonable weather pattern will dominate the forecast, with a few passing showers across windward areas throughout the day and isolated to scattered afternoon showers developing across the southwest quadrant of Puerto Rico today, Thanksgiving Day. Flood risk remains locally limited, as localized ponding on roads and in poorly drained areas cannot be ruled out, but in general, no significant flooding impacts are expected. A similar pattern of trade-wind showers will persist throughout the period, with isolated showers overnight and in the morning across windward areas of Puerto Rico and the vicinity of the U.S. Virgin Islands, followed by isolated to scattered afternoon showers across western municipalities. Model guidance continues to show 925-mb temperatures near the 25th percentile for November climatology, supporting slightly cooler daytime and nighttime temperatures, with no heat-related impacts anticipated. && .Long Term(Sunday through Thursday)... Issued at 518 AM AST Thu Nov 27 2025 Up to breezy conditions are forecast to start the long term period, particularly Sunday to early Monday as a surface high starts the period over the western to central Atlantic, tightening the pressure gradient. 925 mb wind speeds are forecast at high end normal to slightly above normal values during these days, with model guidance suggesting a decrease towards normal values Tuesday and below normal values Wednesday and Thursday. By Tuesday and Wednesday a low pressure system will move out of the eastern US towards the Atlantic promoting a looser pressure gradient and, in turn, these decreasing wind speeds. Precipitable water (PWAT) will be at up to normal values (1.5 to 1.8 in) during the period with patches of drier and slightly more humid air providing some variability. Patches of moisture and nearby troughs will promote showers, steered by mainly northeasterly flow, reaching windward sectors of the islands at times and promote a chance of afternoon showers mainly over interior to SW PR, these can promote brief heavy downpours. Model guidance suggests a trough approaching the region to end the period increasing humidity and instability while also resulting in steering flow veering to become more southeasterly, but uncertainty remains. 925 mb temperatures are forecast to remain at below normal to low end normal values for this time of the year, reaching more normal values to end the period. && .AVIATION... (06Z TAFS) Issued at 518 AM AST Thu Nov 27 2025 VFR conditions are expected to persist over the next forecast period. Periods of VCSH across the USVI and TJSJ today. NE winds with gusty period up to 20 to 25kts aft 227/14Z. Wind speeds becoming lighter aft 27/22Z, around to 10 mph, with land breeze variation overnight. VCSH activity is anticipated, particularly across the windward areas of Puerto Rico and the USVI sites aft 28/00Z. && .MARINE... Issued at 518 AM AST Thu Nov 27 2025 Surface highs over the central Atlantic will continue to promote moderate to fresh easterly winds over the next few days, bringing rough seas across the offshore waters and passages. Small Craft Advisories are in effect through Friday morning for the offshore Atlantic Waters and the Anegada Passage. Small Craft Advisories are also in effect through this morning for the offshore Caribbean Waters and the Mona Passage. Even after the SCAs expire, breezy conditions across most waters and choppy seas up to 6 feet across the Atlantic waters are expected to prevail through early next week. && .BEACH FORECAST... Issued at 518 AM AST Thu Nov 27 2025 There is a moderate risk of rip currents (life-threatening rip currents are possible in the surf zone) for the northern, eastern, southeastern and some southern exposed beaches of Puerto Rico, as well as for Culebra, Vieques and the U.S. Virgin Islands. By tomorrow, southeastern and southern PR is forecast to have a low risk of rip currents. Up to a moderate risk of rip currents will continue through early next week. Visit weather.gov/beach/sju for location-specific information. && .SJU WATCHES/WARNINGS/ADVISORIES... PR...None. VI...None. AM...Small Craft Advisory until noon AST Friday for AMZ711-723. Small Craft Advisory until noon AST today for AMZ733-741. && $$