AFDSJU Area Forecast Discussion National Weather Service San Juan PR 145 PM AST Mon Mar 16 2026 ...New SHORT TERM, AVIATION, MARINE, BEACH FORECAST... .KEY MESSAGES... Issued at 145 PM AST Mon Mar 16 2026 * The US Virgin Islands and Puerto Rico coastal sections can expect strong easterly winds the rest of today, which may blow around unsecured outdoor items and create hazardous conditions, along with fast-moving showers. * Hazardous marine and coastal conditions will persist through much of the week. Small Craft Advisories remain in effect for several local waters, and a high risk of rip currents is expected for many northern and eastern beaches of Puerto Rico and the US Virgin Islands. * Currently, an increasing moisture trend this weekend will enhance the chance of passing showers across Puerto Rico and the US Virgin Islands. && .Short Term(This evening through Wednesday)... Issued at 145 PM AST Mon Mar 16 2026 Once again, this morning, we had variable conditions from mostly sunny skies across the PR`s western half and St Croix to partly sunny and partly cloudy skies across portions of the eastern half of PR, and the US Virgin Islands. A strong surface high-pressure system promoted windy conditions across the islands, with weather stations reporting sustained winds of 20 to 35 mph or higher, gusting to 30 to 40 mph or higher. By the afternoon, showers moved further inland across the mountainous interior and western Puerto Rico. Maximum temperatures ranged from the mid- to upper 80s along the coast to the lower 80s across the mountains. For this afternoon, windy conditions will persist, with gusts up to 40 mph, so the Wind Advisory continues in effect through this evening for Puerto Rico and the US Virgin Islands. Under this wind flow, brief periods of moderate to locally heavy rain will affect mainly the US Virgin Islands and windward areas of PR, producing ponding in poorly drained areas. However, expect periods of sunshine and mostly clear skies overnight. Limited showers will reach western PR, but most activity is expected over windward locations. By this evening, moisture will drop, limiting shower activity, though some showers will arrive occasionally across these windward locations. The stable weather pattern due to a mid-level high pressure will hold across the local Caribbean Region. At the surface, a strong high-pressure system spreading from the western to the central Atlantic will tighten the local pressure gradient, extending breezy to windy conditions across Puerto Rico and the US Virgin Islands. Under the aforementioned weather pattern, the primary hazards during this period will be wind-related conditions. Additionally, an easterly perturbation will arrive around Tuesday morning into the afternoon, promoting showery weather, mainly across the windward areas of Puerto Rico and the US Virgin Islands. However, we expect periods without rain, under pleasant tropical conditions. && .LONG TERM...(Thursday through Monday)... Issued at 250 AM AST Mon Mar 16 2026 A surface high pressure system over the central North Atlantic will maintain a moderate to fresh easterly to east-southeasterly breeze early in the forecast before the pressure gradient gradually weakens ahead of a frontal boundary and associated pre-frontal trough approaching from the northwest. Winds will veer from easterly Thursday to more southerly Friday and Saturday, before becoming more variable and trending northerly by Sunday as the boundary and its pre-frontal trough move across or near the region. Aloft, a mid- to upper-level ridge initially over the northeastern Caribbean will gradually shift southeastward as a polar trough moves into the western Atlantic and then lifts east-northeastward. This evolution may also allow a segment of the subtropical jet to extend southward and remain positioned north of the local islands. At the same time, the trade wind cap will slowly weaken while the atmospheric column progressively moistens. Precipitable water values will begin Thursday slightly below normal with moisture mainly confined below 700 mb, but will increase through Friday as moisture extends deeper into the column. By Saturday and Sunday, widespread above-normal moisture and deeper tropical humidity are expected. Low-level temperatures will remain near seasonal values initially with warm afternoons, followed by a gradual warming trend into the weekend, with the warmest conditions likely Friday and Saturday as southerly flow strengthens. Hazards early in the forecast will mainly be wind-driven. Thursday will still feature breezy conditions, with sustained winds generally around 1721 knots promoting fast-moving trade wind showers mainly across windward areas. As the pressure gradient weakens and winds gradually decrease Friday into the weekend, the hazard focus will shift. The combination of lighter winds, weakening trade wind inversion, increasing instability, and deep tropical moisture will favor slower-moving showers and locally heavier rainfall. As a result, the potential for excessive rainfall and localized flooding may gradually increase from Friday into the weekend as the pre- frontal trough and frontal boundary approach and move through the region. && .AVIATION... (18Z TAFS) Issued at 145 PM AST Mon Mar 16 2026 VFR conditions will persist for all TAF sites during the period. Sfc winds will persist from E up to 25 knots and even occasionally higher gusty winds until 16/22Z. SFC winds will persist up to 10 knots during night for TJSJ, TJPS, TJBQ, and slightly high for TISX & TIST, at 17/14Z winds will increase again. some VCSH to -RA are possible during the period. && .MARINE... Issued at 145 PM AST Mon Mar 16 2026 A strong high-pressure system moving eastward from the western to the central Atlantic will tighten the local pressure gradient, leading to fresh to strong easterly winds. As a result, mariners can expect choppy to rough seas across the regional waters for much of the week. An easterly perturbation will increase shower activity across the regional waters around Tuesday. A frontal boundary along the eastern seaboard, moving eastward, will approach the northeast Caribbean, easing the pressure gradient from Thursday through the end of the workweek. && .BEACH FORECAST... Issued at 145 PM AST Mon Mar 16 2026 Beach conditions will remain dangerous for inexperienced beachgoers across most of the local islands, as breezy to windy easterly winds will generate choppy to rough seas across regional waters, increasing wave action along exposed beaches. As a result, a high risk of rip currents will persist for much of the exposed beaches of the islands. Beachgoers should remain alert to changing coastal conditions and continue monitoring the latest forecasts and statements. For additional information, please visit: weather.gov/beach/sju. && .SJU WATCHES/WARNINGS/ADVISORIES... PR...High Rip Current Risk through Wednesday afternoon for PRZ001>003- 005-007-008-011>013. Wind Advisory until 6 PM AST this evening for PRZ001>013. VI...High Rip Current Risk through Wednesday afternoon for VIZ001-002. Wind Advisory until 6 PM AST this evening for VIZ001-002. AM...Small Craft Advisory until 6 PM AST Wednesday for AMZ711-712-716- 723-726-733-735-741. Small Craft Advisory until 8 PM AST this evening for AMZ745. && $$