textproduct: San Juan

KEY MESSAGES

Issued at 255 PM AST Sun Mar 22 2026

* Variable weather conditions will persist through the rest of the afternoon and evening due to a frontal boundary over the area. Expect cloudy skies and periods of shower activity, at times heavy, with a localized flooding threat, mainly over the eastern third of Puerto Rico, Vieques, and Culebra.

* For the U.S. Virgin Islands, most of the afternoon activity will focus on St. Thomas and St. John. However, shower activity over St. Croix is expected to increase this evening and overnight as the frontal boundary approaches.

* The remnants of the frontal boundary will continue to move over the area during the next few days, resulting in variable weather conditions, particularly across eastern Puerto Rico and the smaller islands.

* A high risk of rip currents along the northern coastal areas, from Mayagez to Fajardo, will persist through at least late tonight. A Small Craft Advisory remains in effect for the offshore Atlantic waters through tomorrow.

Short Term(This evening through Tuesday)

Issued at 255 PM AST Sun Mar 22 2026

Variable to locally unsettle conditions were observed during the morning under cloudy skies as a frontal boundary had been moving across the region. The 12Z TJSJ sounding indicated approximately 2.05 inches of precipitable water. Satellite-derived imagery shows that moisture levels remain in the 75th percentile, which is above normal for this time of year. Radar estimates indicate maximum rainfall accumulations ranging from 1.5 to 2 inches, with isolated amounts up to 3 inches across some northern and southern areas of Puerto Rico. These conditions prompted the issuance of a few Flood Advisories during the morning hours, however, no reports have been received at this time. Across the USVI, rainfall totals have been lower, generally under 0.60 inches. The rest of the day the weather conditions are expected to remain variable through the rest of the afternoon and evening due to a frontal boundary over the area. Cloudy skies and periods of shower activity, at times heavy, with a localized flooding threat, mainly over the eastern third of Puerto Rico, Vieques, and Culebra.

By Monday, as the upper-level trough and surface front shift farther east and remnant moisture from the frontal boundary will linger over the region, including Culebra, Vieques, and the U.S. Virgin Islands. This moisture, combined with local influences, will produce intermittent showers moving in and out of coastal areas in these locations. Meanwhile, winds will continue from the north to northeast steering most of the showers across eastern Puerto Rico and nearby coastal waters, where a limited flood risk will persist. By Tuesday, winds at the surface will shift to come from the east as a high pressure builds over the central Atlantic. Moisture remaining in the area will promote the continuation of variable weather conditions, particularly across eastern Puerto Rico and the smaller islands.

LONG TERM(Wednesday through Sunday)

Issued at 300 AM AST Sun Mar 22 2026

Moisture is expected to increase by mid-week as model guidance indicates precipitable water (PW) values rising to between 1.50 and 2.00 inches, near the 75th percentile for this time of year and therefore above normal. A weak mid- to upper-level trough moving through the region, along with a weak surface perturbation, will promote increasing cloud cover and frequent periods of showers. Temperatures at 500 mb are forecast to be near 7 degrees C, suggesting a moderate potential for instability. This could support occasional heavier showers, although widespread organized convection is not anticipated. The enhanced cloud cover will limit daytime heating, keeping high temperatures near typical seasonal values for March. Winds should remain generally light to moderate, with locally higher speeds possible in and near shower activity. These unsettled conditions are expected to persist through the end of the work week.

By the weekend, a gradual transition toward a drier airmass is anticipated to filter across the islands, leading to decreasing shower coverage and clear to partly cloudy skies. Despite the drying trend, temperatures should remain relatively comfortable and consistent with March.

AVIATION

(18Z TAFS) Issued at 255 PM AST Sun Mar 22 2026

Periods of MVFR/brief IFR conds possible in SHRA, with reduced VIS and lower CIGs (BKN/OVC010-020) are expected thru the next few hours, mainly across TJSJ and TJPS. SHRA/VCTS developing aft 23/03Z, becoming more frequent ovr USVI TAF sites and TJSJ. Monday morning, TJPS & TJSJ are expected to observe additions -RA, as showed with PROB30s. Mainly N to NE winds at around 10 to 15 kts, becoming lighter aft 22/23Z.

MARINE

Issued at 255 PM AST Sun Mar 22 2026

A frontal boundary has moved across the region, leaving behind unsettled marine conditions with lingering showers and a slight chance of thunderstorms across the local waters. A weak long-period northerly swell will result in hazardous seas across the Atlantic waters. In the wake of the boundary, moderate to locally fresh northerly winds are producing choppy seas, particularly across the Mona Passage and offshore Atlantic waters. A surface high-pressure system building over the western to central Atlantic will maintain northeasterly winds through early this week, with increasing winds and seas expected by midweek.

BEACH FORECAST

Issued at 255 PM AST Sun Mar 22 2026

Life-threatening rip currents are likely along the north-facing beaches of Puerto Rico (from Rincn to Fajardo), with a moderate risk of rip currents across Culebra and the U.S. Virgin Islands. Beachgoers should remain cautious, stay near lifeguards, and avoid entering the water if unsure of conditions. Lower risk conditions are expected along the more protected southern beaches, though caution is still advised.

In addition, lingering moisture and instability behind a recently passed frontal boundary will continue to promote showers throughout the day and into tonight. Localized impacts, such as reduced visibility and brief gusty winds, may occur near showers, creating sudden hazardous conditions for beachgoers. A limited thunderstorm risk remains, and any storms that develop could produce lightning, posing a danger to those in or near the water. If thunderstorms approach, seek shelter immediately.

For additional information and location-specific rip current details, please visit: weather.gov/beach/sju.

SJU WATCHES/WARNINGS/ADVISORIES

PR...High Rip Current Risk through late tonight for PRZ001-002-005- 008-010.

VI...None. AM...Small Craft Advisory until noon AST Monday for AMZ711.