textproduct: San Juan

KEY MESSAGES

Issued at 1249 PM AST Mon Jan 19 2026

* Hazardous coastal and marine conditions will continue tonight and Tuesday, with a high risk of rip currents across all north- exposed beaches in Puerto Rico, including Culebra, and the U.S. Virgin Islands. * Breezy to windy conditions are forecast during the workweek, particularly across coastal areas. Unsecured items could blow around.

* Conditions will deteriorate from Wednesday into Friday, increasing the potential for showers and isolated thunderstorms, and resulting in ponding of water over roadways and poorly drained areas.

Short Term(This evening through Wednesday)

Issued at 1249 PM AST Mon Jan 19 2026

Fairly calm conditions prevailed across the islands this morning, with clear to partly cloudy skies and only a few brief and very localized passing showers affecting windward coastal areas of Puerto Rico and the U.S. Virgin Islands. Rainfall accumulations were minimal, and no significant weather impacts were observed. Breezy conditions continued, especially along exposed coastal areas, but overall weather remained tranquil through the morning hours. For this afternoon, similar conditions are expected to persist. A few showers may develop over interior and western portions of Puerto Rico due to daytime heating and local effects; however, these showers should remain very localized with minimal rainfall accumulations.

For the remainder of the short-term period, the frequency of showers is expected to gradually increase as a retrogressing upper-level trough (TUTT) approaches from the east. This feature, along with its associated moisture, will promote increasing atmospheric moisture across the region. Precipitable water (PWAT) values are forecast to fluctuate between near-normal and above-normal levels, ranging from around 1.3 inches to nearly 2.0 inches through Wednesday. In addition, 700-500 mb relative humidity is expected to surge from below normal values to well above normal, particularly by Wednesday.

Instability aloft will also increase gradually as 500 mb temperatures cool and lapse rates steepen between 700 and 500 mb. Despite these changes, thunderstorm activity, if any, is expected to remain very isolated. The best chance for isolated thunderstorms will be over the surrounding waters during the overnight and morning hours, and possibly over interior and western Puerto Rico during the afternoon hours if sufficient diurnal heating develops.

Meanwhile, breezy to windy conditions will persist across the northeastern Caribbean as a strong low-level flow remains in place. 925 mb winds are expected to remain elevated, supporting gusty surface winds, especially across the U.S. Virgin Islands and windward coastal areas of Puerto Rico. With this pattern, streamer- like showers may develop downwind of the smaller islands and mountainous regions, including portions of central Puerto Rico, producing brief periods of moderate to locally heavy rainfall.

Wind conditions are expected to strengthen further on Wednesday, with sustained winds in the low to mid-20s mph possible at times with higher gusts, especially across the U.S. Virgin Islands and windward coastal areas of Puerto Rico. These windy conditions could cause unsecured outdoor items to blow around or sustain minor damage. Overall, while flooding risks remain limited due to fast- moving showers, localized ponding of water on roadways and in poor drainage areas cannot be ruled out during heavier showers.

Long Term(Thursday through next Sunday)

Issued at 511 AM AST Mon Jan 19 2026

Weather conditions from Thursday into Friday will remain variable due to a surface disturbance moving across the islands. According to the global model guidance, abundant surface moisture trapped in the low and mid levels will enhance conditions for frequent, isolated to moderate showers across eastern sections of Puerto Rico and the U.S. Virgin Islands, followed by afternoon showers across the western interior. So far today, the model suggests precipitable water values from Thursday into Friday fluctuating between 1.6 and 1.9 inches, which is slightly above climatological normals. Combine with the moisture, colder temperatures at 500 MB, allowing the development of one or two isolated thunderstorms with the strongest shower activity. Rainfall accumulations for each day are forecast to result mostly in poor driving conditions and some minor flooding in isolated low-lying areas.

Weather conditions will improve by Saturday into Sunday, when the disturbance moves out of the region and a drier airmass filters into the local islands. At the surface, a broad surface high pressure extending across the Atlantic basin will promote mostly easterly wind flow across the area. At the mid to upper levels, subsidence will inhibit well development of showers; however, the local effect would enhance some brief, isolated to moderate showers, with no flooding threat each day. On Monday, the surface conditions will change as veering winds start in response to the pre-frontal trough moving southward near the north of the Hispaniola. Therefore, winds will turn more northeasterly, resulting in a more advective pattern across the area. The northward component of winds will also result in colder temperatures during the morning and night hours.

AVIATION

(18Z TAFS) Issued at 1249 PM AST Mon Jan 19 2026

Mainly VFR conditions will prevail across all terminals through the period. E winds will increase through the afternoon with sustained speeds of 15-20 kt and higher gusts. VCSH/SHRA will continue at times, mainly affecting windward terminals aft 19/23z, briefly reducing VIS and CIGS. Winds diminish slightly overnight but remain breezy.

MARINE

Issued at 1249 PM AST Mon Jan 19 2026

A broad surface high pressure over the Central Atlantic will continue to promote moderate to locally fresh easterly winds tonight and Tuesday. Although winds weaken and swell continues to diminish, choppy to rough seas are still expected, particularly over the Atlantic offshore waters and the Anegada Passage. The Small Craft Advisory remains in effect through at least midnight Tuesday night. However, the Small Craft Advisory will likely be extended as the surface high pressure is expected to strengthen and promote fresh to locally strong winds, deteriorating marine conditions. Small craft operators are encouraged to stay tuned for further updates.

Based on the latest model guidance, marine conditions should gradually improve by the upcoming weekend.

BEACH FORECAST

Issued at 1249 PM AST Mon Jan 19 2026

No changes were introduced to the beach forecast. The high risk of rip currents remains in effect along north and east-facing beaches of Puerto Rico, including Culebra, and the beaches across the U.S. Virgin Islands through late tonight. Residents and visitors are urged to consider other beaches under lower risk and to always swim near a lifeguard.

Although latest buoy observations show a decreased in significant wave height and the swell continues to diminish across the local waters, the high risk of rip currents may persist due strengthening winds. Hence, beachgoers are encouraged to monitor beach conditions and stay tuned for further updates. For more information, visit weather.gov/beach/sju.

Besides rip currents, breezy to windy conditions are expected to continue this workweek, particularly over coastal areas of the islands. Beachgoers are encouraged to secure object that could blow around.

SJU WATCHES/WARNINGS/ADVISORIES

PR...High Rip Current Risk through late tonight for PRZ001-002-005- 008-012.

VI...High Rip Current Risk through late tonight for VIZ001-002.

AM...Small Craft Advisory until midnight AST Tuesday night for AMZ711- 723.