Area Forecast Discussion
Issued by NWS San Juan, PR
Issued by NWS San Juan, PR
780 FXCA62 TJSJ 110823 AFDSJU Area Forecast Discussion National Weather Service San Juan PR 423 AM AST Tue Nov 11 2025 ...New SHORT TERM, LONG TERM, AVIATION, MARINE, BEACH FORECAST... .KEY MESSAGES... Issued at 419 AM AST Tue Nov 11 2025 * Mostly stable weather conditions for today and tomorrow, with only a few areas that would experience afternoon convection and a limited flood threat. * From Saturday into Sunday, weather conditions will deteriorate as a frontal boundary approaches north of the islands. * On Thursday into Friday, a long-period northerly swell will result in a high risk of rip currents along the north-facing beaches in PR and the USVI. * The U.S. Virgin Islands will enjoy stable and fair weather conditions from today into Friday, with some passing showers in the early morning hours. && .Short Term(Today through Thursday)... Issued at 419 AM AST Tue Nov 11 2025 A few showers were observed during the nighttime over the local waters, and occasionally reaching portions of eastern Puerto Rico and the Virgin Islands. However, rainfall accumulations were mostly light, and most of the area saw clear skies and temperatures in the 70s. Generally stable conditions are expected to prevail through much of the workweek. At the upper levels, a ridge is centered just west of Puerto Rico. At the mid levels, the ridge is centered just to the northeast of the Caribbean. At the surface, high pressure is driving the trade winds from the southeast, at speeds just below 15 knots. In these winds, irregular patches of moisture, induced by an upper level trough located east of the Lesser Antilles, will reach the islands at times. This rain interruptions are expected to be brief, and flooding is not anticipated. Also, diurnal heating is expected to fire up showers in the northwest each afternoon, but rainfall accumulation are expected to be minimal as well. Temperatures are expected to be a little warmer than normal, with highs mostly in the upper 80s, and lows in the 70s for coastal areas, and in the 60s in the mountains. && .Long Term...Friday through Tuesday... A variable weather pattern is expected through the long term period as a frontal boundary moves southward during the first part of the forecast. From Friday into early Saturday, the local islands will be dominated by an easterly wind flow. Under this pattern, patches of shallow moisture with precipitable water values between 1.2 and 1.6 inches will persist, remaining near climatological normals. Although some moisture will be present, a mid- to upper-level ridge will limit shower development across most areas, leaving a moderate to high chance of afternoon showers over the western interior on Friday. Late Saturday into the upcoming workweek, the surface pattern will shift as the frontal boundary approaches and weakens the pressure gradient. Winds will veer from the north-northwest late Saturday into Sunday, increasing the potential for passing showers due to a cold advection pattern. This setup will promote showers across the coastal waters and portions of the northern coast during the morning and evening hours. However, significant rainfall accumulations are not anticipated during this period. A surface high pressure building over the western portion of the Central Atlantic will weaken the frontal boundary early next week, returning the local flow to an east-southeast direction from Monday into Tuesday. This will promote a more typical weather regime with heat indices possibly reaching 108 degrees in some areas, followed by afternoon convection across the interior and western Puerto Rico. && .AVIATION... (06Z TAFS) Issued at 419 AM AST Tue Nov 11 2025 Mostly VFR conditions are expected to prevail through the forecast period. SHRA will move at times across the local terminals and surrounding waters, but impacts to operations are expected to be minimal to none. However, from 18-22Z, SHRA are expected in the vicinity of TJBQ, with periods of reduced VIS possible. Winds will be from the SE at 11-14 kts, with gusts around 20 kts, especially from 14-21Z. && .MARINE... Issued at 419 AM AST Tue Nov 11 2025 A broad surface high pressure extending from the north into the Central Atlantic will maintain a moderate to locally fresh easterly wind flow across the regional waters. A north- northwesterly swell is forecast to arrive by Wednesday, increasing seas and producing hazardous marine conditions across the offshore Atlantic waters. Seas are expected to build to around 7 feet. Small Craft Advisories may be required later today or tomorrow. && .BEACH FORECAST... Issued at 419 AM AST Tue Nov 11 2025 A moderate risk of rip currents will persist through today into tomorrow. A north-northwesterly swell arriving by Wednesday will increase seas and result in hazardous surf conditions along the northern beaches of Puerto Rico. Beachgoers should remain alert and stay tuned for updates to the rip current risk forecast.&& .SJU WATCHES/WARNINGS/ADVISORIES... PR...None. VI...None. AM...None. && $$ SHORT TERM & AVIATION...ERG LONG TERM & MARINE....LIS