textproduct: San Juan

KEY MESSAGES

Updated at 215 PM AST Fri Apr 3 2026

* Life-threatening rip currents will continue along north- and east- facing beaches of Puerto Rico and the U.S. Virgin Islands through early next week. Stay out of the water in high-risk areas.

* Choppy to rough seas will result in hazardous marine conditions through early next week, small craft must exercise caution.

* Showers and thunderstorms will develop each afternoon, becoming more widespread and stronger through the weekend and into early next week. Flooding risk will remain elevated, with locally higher impacts possible, especially across Puerto Rico.

* Breezy to locally windy conditions will continue across Puerto Rico and the U.S. Virgin Islands, with stronger gusts in exposed areas and near showers.

Short Term(This evening through Sunday)

Issued at 215 PM AST Fri Apr 3 2026

High pressure over the Atlantic will continue to promote breezy ENE flow this afternoon. This steering flow, however will gradually veer to become more easterly tonight and easterly to ESE on Saturday and ESE on Sunday. Current satellite-derived precipitable water (PWAT) values indicate that the region is between a drier airmass (PWAT values around 1.30 in) to the north and a moist airmass over and south of the region (PWAT values around 1.50 to 1.70 in). Diurnal heating, along with the ENE flow will continue to result in the development of showers and isolated t-storms over the Cordillera towards the southwestern quadrant of PR, as well as showers over the northern USVI towards Culebra and eastern Puerto Rico, over St. Croix and mainly downwind of Vieques. This will result in a limited to elevated flooding risk over mainly over the southwestern quadrant of Puerto Rico. Although these afternoon showers will gradually dissipate and/or move offshore, passing shower activity is expected over windward sectors late tonight as a moist air mass approaches the region. Afternoon convection, including possible isolated t- storms, is forecast for each day across interior and western Puerto Rico, depending on the prevailing steering flow each day. With easterly to ESE winds on Saturday, afternoon convection can concentrate over W-NW PR and downwind of the local islands and El Yunque, and with ESE flow on on Sunday, prompting afternoon convection over NW PR and downwind of the local islands and El Yunque. Increasing moisture over the region (PWAT values will reach above normal, 1.75 in), a nearby upper trough, the lack of a defined trade wind cap and a jet over the region will help shower and t- storm development. A limited to elevated flooding risk will persist over the weekend, resulting in ponding of waters over roads and poorly drained areas. Flooding in urban areas, roads, small streams and washes. There is a chance of isolated flash floods, please continue to monitor for updates. Breezy to locally windy conditions will continue across coastal areas of the islands and can serve to limit rainfall accumulations. Increasing cloud cover at times may limit overall coverage and afternoon convection, especially on Saturday. By Sunday, conditions become more favorable for stronger convection, especially during the afternoon. The ESE flow will steer a warmer and more humid airmass over the region. 925 mb wind speeds will be at 15-20 kts throughout the short term period, promoting quicker moving showers towards windward areas, especially during the morning/overnight hours. 925 temperatures will be below normal to normal (warmer under the ESE flow), gradually increasing throughout the short term period.

Long Term(Monday through next Thursday)

Issued at 200 AM AST Fri Apr 3 2026

A warm and humid pattern remains on track across the northeastern Caribbean through most of the upcoming week, supporting enhanced afternoon convection and a limited to elevated flooding threat across the local islands.

At the surface, a strong high-pressure system migrating from the central to eastern Atlantic will maintain south to southeasterly winds through mid-week. This flow will transport abundant tropical moisture from the Caribbean Sea into the region, with precipitable water (PWAT) values forecast between 1.90 and 2.00 inches throughout the period. Under this pattern, isolated to scattered showers are expected across eastern Puerto Rico and the U.S. Virgin Islands during the morning hours, followed by daily afternoon convection across central, northern, and northwestern Puerto Rico. Daytime heating and local effects will further enhance shower and thunderstorm development. This pattern, combined with high humidity, will elevate the risk of urban and small stream flooding, as well as quick river rises.

As the week progresses, a mid- to upper-level shortwave trough will support the development of a surface trough near Hispaniola, enhancing moisture pooling across the region. By Wednesday, 500 mb temperatures are forecast to drop to around -9C, increasing instability aloft and supporting stronger thunderstorm development. Temperatures are expected to trend warmer early in the period, with 925 mb values rising above climatological normals from Tuesday onward, further supporting afternoon convective activity.

AVIATION

(18Z TAFS) Issued at 215 PM AST Fri Apr 3 2026

Mainly VFR conditions through the period. Brief MVFR conditions are possible mainly at TJPS as -SHRA and and VCTS develops through around 03/22z. VCSH/-SHRA reaching mainly northern and eastern sites from the Atlantic under ENE flow. ENE winds at 12 to 20 kts with higher gusts through this evening, veering to become more E and weakening overnight, and increasing again after 04/13Z from the E to ESE. VCSH/-SHRA reaching mainly northern and eastern sites.

MARINE

Issued at 215 PM AST Fri Apr 3 2026

No changes were made to the marine forecast, as hazardous conditions will continue through the weekend and into early next week. Current nearshore buoys are reporting seas between 4 and 6 feet, while the Ponce and St. John buoys have lowered, between 2 and 3 feet. Additionally, the latest altimeter scans near the CWA show seas between 7 and 8 feet over the Atlantic, while Caribbean waters remain lower (below 6 feet). NDBC buoy 41043 has shown a gradual decrease in seas, meaning that the swell is gradually subsiding. Nevertheless, the remaining energy from the swell will continue to spread across the local Atlantic waters and passages today, gradually subsiding by Sunday. The broad surface high pressure over the western Atlantic will maintain moderate to locally fresh northeasterly winds, veering from the east-southeast by tomorrow, Saturday. Combined with the subsiding northeasterly swell, seas will remain choppy to rough, especially across the Atlantic waters and local passages. Small Craft Advisories remain in effect for the Atlantic offshore and coastal waters, including the Anegada and Mona Passages, through Sunday afternoon.

Trade wind showers will continue across the waters, with isolated afternoon thunderstorms possible over coastal waters, mainly over western Puerto Rico. Small craft must exercise caution, as showers and isolated thunderstorms may result in reduced visibility, gusty winds, and lightning.

BEACH FORECAST

Issued at 215 PM AST Fri Apr 3 2026

Beaches over northern and eastern Puerto Rico, including Vieques and Culebra, and the U.S. Virgin Islands, will remain hazardous for beachgoers this weekend. The northeasterly swell continues to spread across the Atlantic waters and passages, with breezy to locally windy conditions across coastal areas of the islands. The San Juan and Arecibo buoys are currently reporting seas around 6 feet, with a period between 10 and 11 seconds. Taking into consideration bathymetry, these could result in breaking waves between 7 and 9 feet, posing a threat to beachgoers. As mentioned in the Marine section, NDBC buoy 41053 keeps reporting remaining energy from the swell, which will continue to spread across local Atlantic waters and passages. Given the current conditions and expected forecast, the Rip Current Statement remains in effect along the northern and eastern beaches of Puerto Rico, including Vieques and Culebra, and the U.S. Virgin Islands through Sunday afternoon. Beachgoers and inexperienced surfers are urged to avoid going into the water, walking over rocks or jetties, as life-threatening rip currents are very likely. Heed the advice of lifeguards, beach patrol flags, and signs.

In addition to the life-threatening rip currents, beachgoers visiting beaches over south/southwestern Puerto Rico should stay weather alert due to isolated showers and thunderstorms capable to produce gusty winds, periods of heavy showers, and lightning. Seek shelter inside a building whenever you hear lightning.

HYDROLOGY

Issued at 200 AM AST Fri Apr 3 2026

Hydrologic conditions will become increasingly favorable for flooding impacts through the weekend, although uncertainty remains regarding rainfall coverage and persistence. Flooding is not expected to be widespread; however, an elevated risk of urban and small stream flooding is anticipated, with isolated flash flooding possible. Recent rainfall has resulted in saturated soils, especially across eastern and northern Puerto Rico, which will allow water to run off quickly and lead to rapid rises in streams and rivers, including water surges (golpes de agua) in steep terrain. A shift in the pattern will bring more afternoon activity toward northwestern Puerto Rico, and the San Juan streamer could still produce periods of rainfall across the metro area, posing a localized flooding risk.

SJU WATCHES/WARNINGS/ADVISORIES

PR...High Rip Current Risk through Sunday afternoon for PRZ001-002- 005-008-010-012-013.

VI...High Rip Current Risk through Sunday afternoon for VIZ001-002.

AM...Small Craft Advisory until 6 PM AST Sunday for AMZ711-712-716- 723-741.