textproduct: San Juan

KEY MESSAGES

Issued at 300 PM AST Mon Mar 30 2026

* Passing showers and isolated thunderstorms will affect Puerto Rico and the U.S. Virgin Islands each day. Expect morning showers over windward areas and afternoon activity across interior and southwestern Puerto Rico.

* A limited-to-elevated risk of flooding will continue through at least Wednesday, especially in urban areas, low-lying areas with poor drainage, and saturated soils.

* Hazardous marine and coastal conditions will develop late tonight and persist through at least Friday, including rough seas and dangerous conditions for small craft, life-threatening rip currents, and high surf along north-facing beaches.

* Breezy to windy conditions will persist through the week, especially in coastal and exposed areas in PR and the USVI.

Short Term(This evening through Wednesday)

Issued at 300 PM AST Mon Mar 30 2026

Fair weather prevailed today across St Croix and western and southern Puerto Rico, with little or no rain in the morning. Meanwhile, northeasterly winds brought occasional periods of moderate to heavy rain across the windward areas of PR and the northern U.S. Virgin Islands. By noon, showers moved further inland across the interior, south, and southwest PR. Winds were from the northeast at 10 to 20 mph, with gusts up to 30 mph, especially along the coastal sites in Culebra and St. Thomas. Most coastal and urban sites observed maximum temperatures in the mid- to upper 80s, while mountain sites observed maximum temperatures in the mid-70s.

Showers with the possibility of one or two thunderstorms are still possible across the interior and south sections through this evening. While the northeasterly winds will continue to advect patches of clouds producing showers across the windward locations of PR and the US Virgin Islands.

Looking ahead, the northeasterly winds will continue to strengthen, remaining breezy to locally windy through the short- term period, bringing periodic increases in moisture and rain activity. Moisture will increase over the region, especially later tonight and into Tuesday afternoon, then persist into early Wednesday morning, driven by convergence of moisture from the Atlantic along a lingering frontal boundary and a surface trough. This will allow moisture to build across the region, leading to more frequent showers. Although we can expect periods without rain, this activity will bring occasional showers.

Meanwhile, hazardous coastal conditions will develop, especially along north-facing beaches of Puerto Rico and the U.S. Virgin Islands from late tonight through the rest of the short term. A long-period northerly swell will bring: High surf, Life- threatening rip currents, and Possible coastal erosion. If you plan to visit the beach, use extreme caution and consider south- or Caribbean-facing beaches, where conditions are safer.

Long Term(Thursday through next Sunday)

Issued at 300 PM AST Mon Mar 30 2026

An induced surface trough northeast of the region along with a high pressure system well north of the region will maintain a breezy flow from the northeast, around 15 knots on Thursday. Passing showers will continue to move along the Virgin Islands and eastern Puerto Rico in the morning, followed by afternoon convection along the interior and western Puerto Rico. As the trough moves just north of the region, the winds will shift from the southeast by Friday and the weekend. Aloft, a short wave trough arrives on Friday, which usually will be favorable for strong thunderstorm development. However, it looks like that upper level clouds will move from the southwest as well. If the day stays cloudy, then it will shut down the diurnal heating mechanism, preventing heavy rain from developing. Since this is an evolving scenario, the confidence is low to medium at this time. Similar conditions will prevail on Saturday, with the influence of the upper level trough and high clouds moving from the southwest. By Sunday and Monday, there could 153be breaks in the cloud layer, which should allow for more warming and thunderstorms in the afternoon for western Puerto Rico. For these days, the risk of flooding will be elevated, with urban and small stream flooding likely.

By the end of the period, temperatures are expected to warm up too, so highs could climb to the low 90s for most coastal areas in Puerto Rico and the Virgin Islands.

AVIATION

(18Z TAFS) Issued at 300 PM AST Mon Mar 30 2026

Mostly VFR conds across all TAF sites. Nevertheless, brief MVFR contd possible over TJPS from 30/18Z through 30/23Z due to VCTS. Frequent VCSH anticipated over TJSJ, TIST, TISX, and TJBQ after 31/00Z. Winds will remain from NE at 8 to 15kts with occasional higher gust near showers. An additional increase in winds is forecast from 31/13Z across all TAF sites, as winds are forecasts to range from 15 to 20 kt and higher gust at times.

MARINE

Issued at 300 PM AST Mon Mar 30 2026

An approaching frontal boundary and a surface high pressure behind it will promote fresh to strong northeasterly winds, creating choppy to rough seas. Under this weather pattern, expect an increase in the chance of showers and isolated thunderstorms. Additionally, a long-period northerly swell combined with strengthening winds will result in deteriorating marine conditions from this evening and continuing through much of the Spring Break week.

BEACH FORECAST

Issued at 300 PM AST Mon Mar 30 2026

The risk of rip currents will rapidly turn high later this evening along north-facing beaches of Puerto Rico and the U.S. Virgin Islands, while a low risk will persist along south-facing beaches.

Conditions are expected to worsen from late tonight through at least Friday due to the arrival of a long-period northerly swell combined with breezy to windy trade winds. This combination is likely to create life-threatening rip currents and dangerous high- surf conditions along the north-facing exposed coastlines.

Beachgoers should exercise caution and remain aware of changing marine conditions. Always swim near a lifeguard and follow local safety guidance.

SJU WATCHES/WARNINGS/ADVISORIES

PR...High Rip Current Risk from 6 PM AST this evening through Friday evening for PRZ001-002-005-008-010.

High Surf Advisory from 4 AM Tuesday to 6 PM AST Wednesday for PRZ001-002-005-008-010.

High Rip Current Risk from Tuesday morning through Friday evening for PRZ012.

High Surf Advisory from 6 PM Tuesday to 6 PM AST Wednesday for PRZ012.

VI...High Rip Current Risk from Tuesday morning through Friday evening for VIZ001.

High Surf Advisory from 6 PM Tuesday to 6 PM AST Wednesday for VIZ001.

AM...Small Craft Advisory from 6 PM this evening to midnight AST Friday night for AMZ711-712.

Small Craft Advisory from 6 AM Tuesday to midnight AST Friday night for AMZ716-723-741-742.