AFDSJU Area Forecast Discussion National Weather Service San Juan PR 316 AM AST Sun Jan 25 2026 ...New SHORT TERM, LONG TERM, AVIATION, MARINE, BEACH FORECAST... .KEY MESSAGES... Issued at 305 AM AST Sun Jan 25 2026 * Hazardous conditions for small boat continue today along the offshore Atlantic waters, but conditions will gradually improve by tonight. Inexperienced mariners should avoid navigating these waters. * Across the U.S. Virgin Islands, lots of sunshine is expected through the first half of the day, with a few showers reaching the islands later in the afternoon and evening hours. * Partly cloudy skies will persist across Puerto Rico today, with showers developing in the interior and west this afternoon. No flooding risk is anticipated with these showers. && .Short Term(Today through Tuesday)... Issued at 305 AM AST Sun Jan 25 2026 During the overnight hours, clear to partly cloudy skies prevailed across much of Puerto Rico and the U.S. Virgin Islands, with passing showers brushing coastal areas at times. However, shower activity gradually decreased toward the early morning hours as a dry slot approached from the east. GOES-19 PWAT imagery indicated values dropping below one inch within this drier air mass, supporting a notable reduction in rainfall coverage and intensity. As a result, mostly fair weather conditions with little to no rainfall are expected during the morning hours today. A few showers may still develop during the afternoon hours, primarily over interior and western portions of Puerto Rico due to local effects and diurnal heating, but activity is expected to be less frequent and less widespread than observed on yesterday. For the remainder of the short-term period, a mid-level ridge is forecast to build and settle over the northeastern Caribbean. This pattern will promote mid-level drying and increased subsidence, along with warming near the 500 mb level, resulting in reduced instability aloft. Precipitable water values will continue to fluctuate as patches of shallow moisture move across the islands from time to time. Consequently, mostly fair weather conditions are expected to prevail, with passing showers affecting windward coastal areas during the nighttime and morning hours, and some afternoon shower development over interior and western sections of Puerto Rico each day. The frequency and coverage of these showers will largely depend on the timing and extent of these moisture patches. Breezy easterly winds will continue today, particularly across coastal and exposed areas. However, winds are expected to gradually diminish through the end of the short-term forecast period as the surface high pressure over the central Atlantic shifts eastward and a col approaches from the northwest, weakening the pressure gradient across the northeastern Caribbean. && .Long Term(Wednesday through Sunday)... Issued at 305 AM AST Sun Jan 25 2026 The mid to upper level ridge will hold on Wednesday. At the low levels, limited moisture in anticipated, so fair weather should persist until then. Then, there are some changes in store Thursday onward. First, a polar trough will weaken the pressure gradient, causing winds to become lighter. Surface steering flow will fall to nearly 9 knots on Thursday to about 2-6 knots on Friday. The polar trough will escort a cold front near Hispaniola and Cuba, with winds shifting from the south from the surface into the mid levels of the atmosphere. As a result, warmer than normal temperatures are anticipated. Also, the shift in winds will bring a slot of dry air on Thursday, followed by increasing moisture Friday onward. With light winds on Friday, showers are expected to form in the Cordillera Central, where urban and small stream flooding could occur. Then, on the weekend, additional moisture will approach from the south, and also from the north (associated with the cold front). Increasing shower frequency is expected for the Caribbean and Atlantic waters. The proximity of the cold front will cause winds to weaken again on Sunday, with speeds of 1 to 5 knots and variable wind speeds. The global models also show the front crossing late on Sunday, which could cause another increase in showers and thunderstorms across the area. && .AVIATION... (06Z TAFS) Issued at 305 AM AST Sun Jan 25 2026 VFR conds will prevail across all terminals thru the fcst period. Passing SHRA may affect mainly windward terminals at times, but no sig VIS or CIGs restrictions are expected. Winds will remain from the EENE at 1016 kt with higher gusts possible, especially aft 25/14Z.&& .MARINE... Issued at 305 AM AST Sun Jan 25 2026 A building high pressure centered over the western Atlantic, north of the islands, will bring moderate to fresh tonight through Monday. Winds will remain moderate toward the middle portion of the week as the high rolls into the central and eastern Atlantic. Showers will be less frequent today, moving across the Atlantic and Caribbean waters. && .BEACH FORECAST... Issued at 305 AM AST Sun Jan 25 2026 Breezy conditions will maintain a moderate rip current risk for the north and east facing beaches of Puerto Rico, as well as for Vieques, Culebra and all the beaches across the Virgin Islands. Similar conditions are expected to persist through the upcoming days, with only the west, south, and southwest of Puerto Rico with a low risk of rip currents. && .SJU WATCHES/WARNINGS/ADVISORIES... PR...None. VI...None. AM...Small Craft Advisory until 6 PM AST this evening for AMZ711. && $$