textproduct: San Juan

KEY MESSAGES

Issued at 500 AM AST Fri Dec 26 2025

* Northerly swell activity today and through the weekend will maintain hazardous marine conditions and life-threatening rip current risks, particularly across Atlantic waters and north- and east-facing beaches. While surf heights may fluctuate, the potential for high surf conditions cannot be ruled out, especially with additional swell pulses on Saturday.

* Typical December weather is expected over the next few days, characterized by cooler temperatures and periods of trade-wind showers, mainly during the overnight and early morning hours. No significant weather hazards are anticipated during this period. However, a gradual increase in moisture and instability from Wednesday into Thursday (New Years period) may result in more frequent showers and a low potential for isolated lightning activity.

* U.S. Virgin Islands: The primary threats will be marine and coastal, driven by ongoing northerly swell activity and life- threatening rip current conditions. Otherwise, typical seasonal weather conditions are expected, with brief passing showers and cooler temperatures.

Short Term(Today through Sunday)

Issued at 500 AM AST Fri Dec 26 2025

Northerly swell activity today and through the weekend will maintain hazardous marine conditions and life-threatening rip current risks, particularly across Atlantic waters and north- and east-facing beaches. While surf heights may fluctuate, the potential for high surf conditions cannot be ruled out, especially with additional swell pulses on Saturday.

Typical December weather is expected over the next few days, characterized by cooler temperatures and periods of trade-wind showers, mainly during the overnight and early morning hours. No significant weather hazards are anticipated during this period. However, a gradual increase in moisture and instability from Wednesday into Thursday (New Years period) may result in more frequent showers and a low potential for isolated lightning activity.

U.S. Virgin Islands: The primary threats will be marine and coastal, driven by ongoing northerly swell activity and life- threatening rip current conditions. Otherwise, typical seasonal weather conditions are expected, with brief passing showers and cooler temperatures.

Long Term(Monday through Friday)

Issued at 500 AM AST Fri Dec 26 2025

A shift in the weather pattern is expected this week. After a relatively dry start on Monday and Tuesday, wetter conditions return Tuesday night and persist through Friday as a weak frontal boundary dissipates and a short-wave polar trough approaches the region, with a surface trough reflection increasing moisture and instability later in the week. Showers will become more frequent, with periods of moderate to locally heavy rainfall, especially from Thursday afternoon into Friday. While widespread flooding is not expected, localized urban and small-stream flooding will be possible, mainly across windward and interior areas of Puerto Rico and portions of the U.S. Virgin Islands. Confidence is moderate that late-week rainfall will be the most impactful part of the period.

Thunderstorm activity is expected to remain limited overall, which is typical for this time of year, but there is a low to moderate chance of thunderstorms Thursday into Friday as the trough briefly enhances instability and supports isolated thunderstorm development. Winds will remain a gentle east-southeast to southeast breeze through Thursday, then veer to the east and strengthen to a moderate breeze from Thursday night into Friday as surface high pressure builds and shifts eastward over the North Atlantic. Temperatures will trend slightly warmer from Wednesday through New Years, with cooler conditions expected to return late in the week. Confidence is high in the late-week increase in wind speeds, resulting in breezy conditions at times, especially along exposed coasts and higher elevations.

AVIATION

(06Z TAFS) Issued at 500 AM AST Fri Dec 26 2025

Mainly VFR conditions expected to prevail. SHRA will move at times, reaching TJSJ and USVI terminals, but impacts to operations are expected to be minimal. After 18z, SHRA will develop near TJPS, with brief periods of reduced VIS and low ceilings possible. Winds will be from the NE at 7-9 kts.

MARINE

Issued at 500 AM AST Fri Dec 26 2025

A surface high pressure centered over the western Atlantic will promote light to moderate east to northeast winds over the next few days. Meanwhile, pulses of a long-period northerly swell will invade the local waters and deteriorate marine conditions, resulting in hazardous seas for small craft, with Small Craft Advisories in effect from tonight through Saturday night. Additional pulses of northerly swell are expected early next week, which will likely once again bring hazardous conditions for small craft across the local waters. Typical trade-wind shower activity will continue to affect the region, especially during the nighttime hours.

BEACH FORECAST

Issued at 500 AM AST Fri Dec 26 2025

A High Rip Current Risk continues today across the Atlantic-facing beaches of Puerto Rico and Culebra, despite subsiding swell and gradually improving marine conditions. Hazardous rip current conditions will remain possible across more protected southern- facing beaches, as well as Vieques and most U.S. Virgin Islands beaches, although the risk there is less elevated compared to Atlantic-facing shores.

Additional pulses of northerly swell arriving tonight are expected to reinforce life-threatening rip current conditions, with the high risk expanding to the northern U.S. Virgin Islands on Saturday. While it is too early to determine exact surf heights, the potential for high surf conditions exists, and the issuance of High Surf Advisories cannot be ruled out later today or this evening.

Beachgoers are strongly urged to remain out of the water, especially at unguarded beaches, and to heed all local beach safety statements and advisories. For further information, refer to the Coastal Hazard Message (CFWSJU).

SJU WATCHES/WARNINGS/ADVISORIES

PR...High Rip Current Risk through late Saturday night for PRZ001-002- 005-008-010-012.

VI...High Rip Current Risk from Saturday morning through late Saturday night for VIZ001.

AM...Small Craft Advisory from 6 PM this evening to 6 PM AST Saturday for AMZ711.

Small Craft Advisory from midnight tonight to 6 PM AST Saturday for AMZ712-716-723-741-742.