Marine Weather and Tide Forecast for Cataño, PR

.Short Term(Today through Monday)...
Issued at 232 AM AST Sat Jul 25 2026

A wind surge ahead of a tropical wave will continue to bring patches of low-level moisture across the region today. Breezy easterly trade winds and passing showers can be expected throughout the day, while weakening of the Saharan Air Layer will reduce dust concentrations. However, the available low-level moisture will combine with diurnal heating and local orographic effects to produce localized afternoon showers and isolated thunderstorms once again across the interior and western PR. Max temps are expected to range from the upper 80s to low 90s across the lower elevations, and from the upper 70s to mid 80s across the higher elevations of the islands. Heat indices are expected to remain below heat advisory criteria due to the expected cloud coverage.

The weather pattern will evolve from late Sunday into Monday as the tropical wave approaches the islands. Simultaneously, an upper-level low is expected to move over the region, lowering 250mb heights and dropping mid-level (500mb) temperatures down to around -9C, eroding the low-level trade wind cap and destabilizing the atmospheric column. Moisture content will gradually increase, with guidance showing precipitable water (PWAT) values surging above seasonal levels, exceeding 2.00 inches through this period.

With lighter steering winds and higher moisture content on Monday, slow-moving showers and thunderstorm clusters are anticipated to develop over portions of the islands and regional waters. The strongest convective development will focus over the interior, northern, and western portions of Puerto Rico during the afternoon. Prolonged heavy rainfall from these slow-moving cells will elevate the potential for urban and small stream flooding, localized river rises, and ponding of water on roadways and poorly drained areas. Additionally, due to the expected favorable position of the upper-level low, these thunderstorms can produce frequent lightning and strong gusty winds.

.Long Term(Tuesday through Friday)...
Issued at 232 AM AST Sat Jul 25 2026

The latest model guidance continues to suggest above-normal precipitable water (PWAT) values exceeding 2.00 inches by the beginning of the long-term period, as moisture associated with a passing tropical wave continues to linger across the area. At the upper levels, an upper-level low will begin to migrate northwestward away from the region, providing some stability aloft that will be reflected in rising heights and warmer mid-level temperatures (at 500 mb). At the surface, a high-pressure system will continue to strengthen, resulting in breezy to locally windy east-southeasterly winds across the area.

Under this scenario, moisture content will remain above average and when combined with local effects and diurnal heating, will likely support fast moving showers during the morning hour across the windward areas of the islands, followed by afternoon convection across the interior and western portions of Puerto Rico. During this period, ponding of water on roads and in poorly drained areas is possible.

From Wednesday onwards, a drier airmass will filter into the region, dropping PWAT values below normal to around 1.30 inches. This drier airmass will be accompanied by low concentrations of Saharan dust through at least Saturday. Despite the expected drier pattern, patches of moisture embedded in the trade winds will continue to reach the region, bringing fast-moving, passing showers across portions of Puerto Rico and the U.S. Virgin Islands with minimal to no impacts. Normal to above-normal temperatures will persist across the area, with daytime highs remaining between the upper 80s and low 90s in coastal and urban locations. Residents and visitors are encouraged to stay hydrated and monitor local weather updates.

AVIATION
(06Z TAFS)
Issued at 232 AM AST Sat Jul 25 2026

A wind surge and the proximity of an upper-level low will bring quick passing SHRA and brief gusty winds across the USVI/eastern PR terminals through the early morning hours. This may lead to brief MVFR cigs. Iso TSTMs with max tops to 380 were observed S-SW of St. Croix, and may cause VCTS till sunrise. Afternoon SHRA/TSRA expected to develop in and around the PR terminals thru sunset. However, mostly VCSH/VCTS expected. HZ due to Saharan dust will continue but VSBY should remain P6SM. East winds at 15-25 kt blo FL080.

MARINE
Issued at 232 AM AST Sat Jul 25 2026

Moderate to locally fresh easterly winds will continue through the weekend, producing choppy seas and hazardous conditions for small craft across portions of the local waters. Winds are expected to decrease early next week, leading to improving marine conditions.
Scattered showers and isolated thunderstorms will increase late Sunday into Monday as a tropical wave approaches. Saharan dust will gradually diminish, although low concentrations will linger into early next week.

BEACH FORECAST
Issued at 232 AM AST Sat Jul 25 2026

A moderate risk of rip currents will continue through the rest of the weekend across beaches of northern and eastern Puerto Rico, Vieques, Culebra, and St. Croix. As winds decrease early next week, the rip current risk should gradually lessen, resulting in improving beach conditions through midweek. However, life- threatening rip currents will remain possible near reefs, jetties, groins, and piers. The rip current risk is expected to increase again later in the workweek as easterly winds strengthen.
Beachgoers should also remain alert for thunderstorms and heat.

SJU WATCHES/WARNINGS/ADVISORIES
PR...None.
VI...None.
AM...None.