textproduct: San Juan

KEY MESSAGES

Issued at 411 AM AST Sun May 24 2026

* Similar to previous days morning showers will continue to move across the windward areas of Puerto Rico and the U.S. Virgin Islands. Then, afternoon convective activity will result in showers and isolated thunderstorms, across central and western Puerto Rico. * Breezy to locally windy conditions will continue through the midweek. Secure loose objects, especially along coastal areas.

* Moderate to fresh easterly winds winds will result in choppy seas and a moderate risk of rip currents across most local beaches, likely increasing to a high risk by Monday.

* A Small Craft Advisory remains in effect through at least Tuesday morning for portions of the offshore Atlantic waters. Small craft operators should continue to exercise caution elsewhere.

Short Term(Today through Tuesday)

Issued at 411 AM AST Sun May 24 2026

Similar to previous days, weather conditions were variable during most of the overnight hours, with fast-moving showers affecting portions of eastern, southeastern, and northern Puerto Rico, with no impacts across the area. Across the U.S. Virgin Islands, Culebra, and Vieques, mainly fair weather prevailed under mostly clear to partly cloudy skies. Minimum temperatures ranged from the mid to upper 70s across coastal and urban areas, and from the mid to upper 60s along the central mountain range. Easterly winds prevailed at 5 to 10 mph, with occasional higher gusts and land breeze variations.

Another active day is anticipated across the region today as deeper moisture continues to filter into the forecast area. Precipitable water (PWAT) content of 1.80 to 2.0 inches, combined with favorable upper-level dynamics, will support the development of convective activity, particularly during the afternoon hours. Heavy rainfall is expected once again today across the interior and western Puerto Rico. Mid-level temperatures (700500 mb) near -8 to -9 degrees Celsius will further enhance the development of isolated thunderstorms. Meanwhile, a strong high pressure system dominating the central Atlantic will maintain windy conditions across the area under an easterly wind flow of 15 to 20 knots.

Similar weather conditions are expected to persist into Monday afternoon; however, PWAT values will drop to around 1.40 inches with the arrival of a drier air patch, limiting activity to localized showers across western Puerto Rico. Despite this brief drying, the flooding risk will remain elevated across the area. By Tuesday, PWAT values are expected to increase once again to near 2.25 inches, well above normal climatological values as deeper moisture filters into the area and an upper-level trough move northeast of the islands. Consequently, active afternoons will remain in the outlook through midweek.

Seasonal temperatures will persist through midweek, with maximum temperatures expected to range from the mid to upper 80s along coastal and urban areas, and from the upper 70s to low 80s in the higher elevations.

Long Term(Wednesday through Sunday)

Issued at 411 AM AST Sun May 24 2026

A wet and some slightly unstable weather pattern is expected to develop across Puerto Rico and the U.S. Virgin Islands on Wednesday as tropical moisture moves across the region as suggest the GFS and the ECMWF global model guidances. PWAT values from the moisture arriving in the islands are forecast to range between 2.00 and 2.16 inches, which is within the normal climatological range for the season. At the surface, a broad high pressure over the central Atlantic will promote east-southeasterly winds, favoring warm conditions across northern and western Puerto Rico, resulting in heat indices in the 100s. Aloft, some instability will be present due to a low-pressure system near 250 mb reflecting into the mid- levels around 500 mb, enhancing upper-level support for shower and thunderstorm development. Under this pattern, periods of showers and isolated thunderstorms are expected across the local waters and windward sectors during the morning hours, followed by stronger convection across the interior and northwestern Puerto Rico during the afternoon. Urban and small-stream flooding, ponding of water on roads, remain possible due to slow-moving showers. Frequent lightning and gusty winds will also pose hazards near the strongest thunderstorms. Across the U.S. Virgin Islands, shower activity will be more limited and fast-moving, although isolated ponding of water cannot be ruled out. Additionally, by late Wednesday into Thursday, the NASA Goddard Earth Observing system model V5 suggest an increase of the particles of Saharan dust across the islands.

From Thursday through Saturday, improving conditions aloft near 250 mb will gradually promote a more stable weather pattern across the forecast area. At the surface, strengthening high pressure spreading into the eastern Atlantic will tighten the pressure gradient and shift winds more from the southeast, resulting in breezy to locally windy conditions. This wind flow will support a warming trend across the islands, as forecast 925 mb temperatures show. Heat indices are expected to reach elevated levels each afternoon, especially across northern, western, and urban sections of Puerto Rico, increasing the risk of heat-related illnesses for sensitive populations. Although a more stable pattern is forecast overall, local effects and daytime heating will still support afternoon convection each day, particularly along the northwestern quadrant and portions of the San Juan metropolitan area. Brief periods of heavy rainfall, lightning, and gusty winds will remain possible, with the strongest activity occurring. By Sunday, a surface trough developing over the western Atlantic will promote a more southerly wind flow across the region while PWAT values decrease closer to around 1.60 inches. This pattern may continue the warm conditions across the islands while maintaining isolated to scattered afternoon convection, mainly over western and northwestern Puerto Rico.

AVIATION

(06Z TAFS) Issued at 411 AM AST Sun May 24 2026

Mainly VFR conds expected across all TAF sites. Fast moving SHRA will result in -SHRA/VCSH across the TJSJ/TIST/TISX thru 24/14Z. Aftn SHRA/TSRA will develop across central, western PR, and downwind from El Yunque possibly resulting in brief MVFR/IFR conds over TJBQ/TJSJ btwn 24/16-22Z. SCT-BKN cigs btw FL030-050 and mtn tops obscd expected across all the islands. E winds up to 15-20 kts after 24/14Z, with higher gusts and sea breeze variations, decreasing to 5-10 kts aft 24/23Z.

MARINE

Issued at 411 AM AST Sun May 24 2026

Moderate to fresh easterly winds will persist across the regional waters through next week as strong high pressure remains anchored over the central Atlantic. This pattern will maintain choppy to rough seas of up to 7 feet across the offshore Atlantic waters and local passages. As a result, a Small Craft Advisory remains in effect through at least Tuesday morning for portions of the offshore Atlantic waters, while small craft operators elsewhere should continue to exercise caution. In addition, isolated afternoon thunderstorms may develop near the western coastal waters of Puerto Rico each day, producing locally higher winds and seas.

BEACH FORECAST

Issued at 411 AM AST Sun May 24 2026

The persistent easterly wind flow will maintain a moderate risk of rip currents through the weekend for many north- and east-facing beaches of Puerto Rico, Culebra, Vieques, and portions of the U.S. Virgin Islands. Winds are expected to strengthen further early next week as the Atlantic pressure gradient tightens.

Consequently, the risk of rip currents will likely increase to high across many exposed beaches Monday into Tuesday. Beachgoers should exercise caution and heed the advice of local officials and beach safety personnel. Afternoon thunderstorms are also possible each day across western Puerto Rico; if thunder is heard, seek shelter immediately. For additional information and location-specific rip current forecasts, visit weather.gov/beach/sju.

SJU WATCHES/WARNINGS/ADVISORIES

PR...None. VI...None. AM...Small Craft Advisory until 6 AM AST Tuesday for AMZ711.