textproduct: San Juan

KEY MESSAGES

Issued at 518 AM AST Wed Nov 26 2025

* Up to breezy conditions will continue due to a surface high pressure over the Central Atlantic. * Wind-driven seas will result in choppy and hazardous marine conditions for small craft. A small craft advisory will be in effect later tonight for the local offshore Atlantic.

* Periods of showers will affect mainly the windward locations of Puerto Rico and the U.S. Virgin Islands at times. Afternoon showers are forecast today mainly for SW PR.

* There is a moderate risk of rip currents for the northern exposed beaches of PR, as well as for Culebra, Vieques and St. Croix; this risk will spread this evening to eastern PR, southeastern PR, St. John and St. Thomas.

Short Term(Today through Friday)

Issued at 518 AM AST Wed Nov 26 2025

During the overnight hours, showery weather persisted across the local waters, with a few showers reaching northern and eastern Puerto Rico and the vicinity of the U.S. Virgin Islands. These produced no significant impacts, and radar estimated rainfall totals were minimal. Surface observations showed winds influenced by land- breeze fluctuations, generally at 8 to 10 mph or less, with occasional slightly higher gusts. Minimum temperatures ranged from the low to mid-70s across coastal areas and the U.S. Virgin Islands, and into the low 60s or slightly lower across the mountains and interior valleys of Puerto Rico.

At the surface, high pressure over the western Atlantic continues to move eastward into the central Atlantic, tightening the pressure gradient and supporting a persistent northeasterly flow across the region. As a result, breezy trade winds are expected today and tomorrow, with a slight decrease anticipated by Friday. Aloft, a shortwave trough will move away today and tonight, allowing weak ridging to briefly develop before a polar trough moves across the central Atlantic, altering the upper-level pattern. Precipitable water values are forecast to remain below normal today (1.20 to 1.30 inches) as mixed patches of dry and slightly more humid air stream in under the northeasterly flow. Under this pattern, no significant rain hazards are expected. There is a slight chance of morning showers across the U.S. Virgin Islands and windward areas of Puerto Rico, and a slight to moderate chance of afternoon showers across southwestern Puerto Rico. With increasing wind speeds, any showers will move quickly, further limiting rainfall accumulations and keeping flood risk very low to none.

Tonight, moisture content will increase to near-normal levels (around 1.5 to 1.6 inches), and with the axis of the upper-level shortwave trough still present, an uptick in shower activity is anticipated, particularly across the windward areas of Puerto Rico and the U.S. Virgin Islands.

A similar pattern of trade-wind showers will persist on Thanksgiving Day and Friday, with isolated showers overnight and in the morning, followed by isolated to scattered afternoon showers across western municipalities. No significant flooding impacts are expected though.

Model guidance continues to show 925-mb temperatures near the 25th percentile for November climatology throughout the forecast period, supporting more pleasant daytime and nighttime temperatures with no heat risk impacts anticipated.

Overall, expect quick-moving passing showers with little to no flood threat, fresher temperatures. Strengthening winds will be the primary weather concern, producing breezy conditions that may cause unsecured items, especially near coastal areas, to be blown around.

Long Term(Saturday through Wednesday)

Issued at 518 AM AST Wed Nov 26 2025

Generally breezy conditions are forecast to start the long term period, particularly Saturday to Monday as a surface high builds over the western to central Atlantic and tightens 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 Wednesday. By Tuesday and Wednesday a low pressure system will move out of the eastern US towards the Atlantic promoting a looser pressure gradient and promote more seasonal wind speeds. PWAT values will be at up to normal values (1.5 to 1.8 in) with patches of drier and slightly more humid air providing some variability. Patches of moisture will promote showers steered by east- northeast, becoming more northeasterly as the period progresses, flow to reach windward sectors of the islands at times and promote a chance of afternoon showers mainly over interior to SW PR. Model guidance suggests the Wednesday will be the most humid day with PWAT values at around 1.9 to 1.9 in, but uncertainty remains. Flooding risks are not forecast during the period but above mentioned showers can promote brief heavy downpours. 925 mb temperatures are forecast to remain at below normal to low end normal values for this time of the year.

AVIATION

(06Z TAFS) Issued at 518 AM AST Wed Nov 26 2025

VFR conditions will persist along all the TAF sites during the day. Expect period of VCSH across the USVI and TJSJ this morning. E to NE wind flow will dominate, becoming breezy with gust up to 20 to 25 mph aft 26/14Z. Wind speeds becoming lighter aft 26/21-22Z, around 8 to 10 mph, with land breeze variation overnight. An uptick in shower activity is anticipated, particularly across the windward areas of Puerto Rico and the USVI sites aft 27/02Z.

MARINE

Issued at 518 AM AST Wed Nov 26 2025

A building surface high pressure moving into the central Atlantic will bring moderate to locally fresh easterly winds over the next few days. A dissipating northeasterly swell will also be present early today. A Small Craft Advisory will be in effect from late tonight through Friday morning for the Atlantic offshore waters due to locally choppy wind waves. Small Craft should still exercise caution over other local waters. Increasing winds and building seas are also forecast by Saturday night and into early next week.

BEACH FORECAST

Issued at 518 AM AST Wed Nov 26 2025

There is a moderate risk of rip currents for the northern exposed beaches of Puerto Rico, as well as for Culebra, Vieques and St. Croix. This evening the moderate risk of rip currents is forecast to spread towards eastern PR, southeastern PR, St. John and St. Thomas. By early tomorrow, areas of southern PR will also be under a moderate risk of rip currents. Up to a moderate risk of rip currents will continue during the rest of the week with localized areas possibly under a high risk of rip currents tomorrow night. Always check the beach forecast before heading out, and avoid swimming at beaches with a high risk of rip currents. For location-specific information, visit weather.gov/beach/sju.

SJU WATCHES/WARNINGS/ADVISORIES

PR...None. VI...None. AM...Small Craft Advisory from midnight tonight to noon AST Friday for AMZ711.