textproduct: San Juan

KEY MESSAGES

Issued at 200 AM AST Wed Apr 1 2026

* Dangerous rip currents continue along north- and east-facing beaches. Stay out of the water. Rough surf persists through this afternoon.

* Hazardous seas will continue for small craft through at least Friday night and likely into the weekend.

* Showers move across windward areas overnight and in the morning, then focus over southwestern Puerto Rico in the afternoon. Brief heavy rain may cause localized flooding, with lightning and gusty winds possible.

* Winds remain strong, around 15 to 20 mph with higher gusts, especially near showers and in exposed areas.

Short Term(Today through Friday)

Issued at 200 AM AST Wed Apr 1 2026

A strong high pressure system over the western Atlantic will maintain breezy trade winds across the region through the rest of the workweek. Sustained winds will generally range between 15 and 20 mph, with gusts between 25 and 30 mph, and locally higher gusts possible near showers and across exposed areas. Moisture will remain near seasonal levels today, supporting passing showers across windward areas through the morning hours, followed by the development of showers and isolated thunderstorms mainly over the far southwestern sections of Puerto Rico this afternoon.

A wetter pattern will gradually develop from late tonight onward as a band of above-normal moisture moves in from the northeast and spreads across the local islands. Moisture will become deeper and more established by Thursday night into Friday, resulting in more frequent passing showers across eastern and northern Puerto Rico and the U.S. Virgin Islands, followed by enhanced afternoon convection over portions of western Puerto Rico. The lack of a well-defined trade wind cap, combined with nearby upper-level troughiness, will favor more efficient shower development, although thunderstorm activity should remain isolated.

The highest rainfall totals each day will remain localized and primarily driven by diurnal heating, terrain effects, and low- level convergence. As winds gradually veer from the northeast to the east and eventually east-southeast, the area of greatest activity is expected to shift from the far southwestern portions of Puerto Rico today toward western and northwestern Puerto Rico by Friday.

The main concern through the short-term period will be the increasing potential for locally heavy rainfall and localized flooding, especially in urban areas, roads, and poor drainage locations from late Thursday through Friday, when the deepest moisture is expected. While showers will generally move quickly, repeated activity over the same areas may lead to rainfall accumulations of around 1 to 2 inches, with locally higher amounts possible, particularly across western and northwestern Puerto Rico by late in the week. The strongest winds are expected late Thursday into Friday, especially across exposed coastal areas, higher elevations, and surrounding waters.

Long Term(Saturday through Wednesday)

Issued at 200 AM AST Wed Apr 1 2026

For the beginning of the long-term period, a weather pattern influenced by an induced surface trough and an upper-level shortwave trough is expected. This combination will lead to increasingly unstable conditions across the islands. As the disturbance moves west of the region, its interaction with a high-pressure system over the Central Atlantic will promote an east-southeasterly wind flow.

The upper-level trough will enhance instability and support thunderstorm development, resulting in a high probability of showers. However, a deep upper-level cloud layer may limit daytime heating, potentially reducing widespread activity. Even so, localized, well-developed showers are expected, especially across northwestern areas and the San Juan metro region. By Sunday, precipitable water values are forecast to reach around 1.7 inches, near the 75th percentile for this time of year. A limited to elevated flood risk will persist each afternoon. As a result, similar conditions are expected on Sunday, as the upper-level trough continues to influence the region along with periods of enhanced cloud cover. During this time, a limited to elevated flood risk will persist each afternoon.

From Monday through Wednesday, the surface pattern will become dominated by a broad high-pressure system over the Central Atlantic, resulting in southeasterly winds. During this period, increasing low- level moisture from the Caribbean will spread across the islands, with precipitable water values rising to around 1.9 inches and remaining near the 75th percentile, based on climatological data for this time of the year. With weaker upper-level dynamics, cloud cover aloft will be less extensive, allowing for more effective daytime heating. As a result, afternoon convection is expected to become more widespread and better organized, particularly across western and interior Puerto Rico, where local effects will enhance shower and thunderstorm development. This pattern, combined with warm and humid conditions, will increase the risk of urban and small stream flooding.

AVIATION

(06Z TAFS) Issued at 200 AM AST Wed Apr 1 2026

SHRA will affect mainly windward terminals overnight into 01/14Z with periods of MVFR (cigs 23 kft, vsby 35 SM). TJPS less impacted early, but SHRA possible aft 01/17Z with brief MVFR conditions. SHRA redevelop ovr windward terminals aft 01/22Z. NE winds 1015 kt overnight, incr to 1520 kt with gusts 2530 kt aft sunrise, remaining breezy and gusty.

MARINE

Issued at 200 AM AST Wed Apr 1 2026

Hazardous marine conditions will persist through the week under a strong Atlantic high-pressure system. Fresh to strong northeasterly winds and a persistent northerly swell will maintain choppy to rough seas across regional waters, with conditions continuing even as winds shift easterly. Frequent trade wind showers will move across the Atlantic waters and local passages, with isolated afternoon thunderstorms possible over the Caribbean waters. Small Craft Advisories remain in effect for northern and exposed waters through at least Saturday.

BEACH FORECAST

Issued at 200 AM AST Wed Apr 1 2026

Hazardous coastal conditions will persist across Puerto Rico and the U.S. Virgin Islands through the rest of the workweek and possibly into the weekend. A long-period northerly swell will continue to impact exposed coastlines, resulting in a high risk of rip currents, dangerous surf, beach erosion, and large breaking waves. The most hazardous conditions are expected along north- and east-facing beaches of Puerto Rico, including Culebra and Vieques, as well as the northern U.S. Virgin Islands. A High Surf Advisory remains in effect through this afternoon, with a high risk of rip currents continuing beyond that period through at least Friday night.

Beachgoers are strongly urged to stay out of the water and exercise caution near the shoreline, as breaking waves and wave run-up can sweep people off rocks and beacheseven those not entering the water are at risk. Elsewhere, a low to moderate risk of rip currents will persist; however, hazardous conditions can still occur. Swim only near lifeguards and follow local safety guidance.

SJU WATCHES/WARNINGS/ADVISORIES

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

High Surf Advisory until 6 PM AST this evening for PRZ001-002- 005-008-010-012-013.

High Rip Current Risk through Thursday afternoon for PRZ013.

VI...High Rip Current Risk through late Friday night for VIZ001.

High Surf Advisory until 6 PM AST this evening for VIZ001.

High Rip Current Risk from 8 AM AST this morning through late Friday night for VIZ002.

AM...Small Craft Advisory until 6 AM AST Saturday for AMZ711-712-716- 723-741-742.

Small Craft Advisory until 6 AM AST Friday for AMZ726.