textproduct: San Juan

KEY MESSAGES

Updated at 1250 PM AST Mon May 25 2026

* Breezy to windy conditions are expected the rest of today. A Wind Advisory is in effect through this evening due east winds around 25 mph and winds gusts up to 40 mph.

* Hazardous marine and coastal conditions will persist through at least late Tuesday, with Small Craft Advisories and a high risk of rip currents remaining in effect.

* Warm to hot conditions will persist through much of the week, with hotter conditions anticipated by the end of the week.

* Afternoon showers and very isolated thunderstorms could still impact western portions of Puerto Rico despite the arrival of a drier airmass over the region today. Uptick of passing showers across windward coastal areas and smaller islands tonight.

* Minor to moderate concentrations of Saharan dust are forecast to arrive by midweek and persist into late week.

Short Term(This evening through Wednesday)

Issued at 1250 PM AST Mon May 25 2026

Strong winds between 25 and 30 mph with gusts between 35 and 40 mph were observed across the islands today, particularly across coastal areas. These windy conditions will continue through tonight, and a Wind Advisory remains in effect through 8 PM AST. Quick passing showers will continue to move at times across the islands, but rainfall accumulations should not cause flooding concerns, except in western PR, where ponding of water is possible this afternoon. The latest 12z TJSJ upper-air sounding shows a relatively low precipitable water (PWAT) of 1.29 inches, with a persistent mid-level dry slot and a capped environment. However, satellite imagery from the MIMIC-Total Precipitable Water product captures plenty of tropical moisture just to our south and east. GFS guidance shows PWAT values rapidly surging above the 75th percentile, peaking near 2.10 inches by Tuesday afternoon. This surge in moisture will be accompanied by 925 mb wind speeds of 20 to 25 knots and the erosion of the mid-level inversion, as 700-500 mb lapse rates steepen to near 6.5-7.0 C/km and 500 mb temperatures linger near normal values around -8 C.

As this moisture combines with daytime heating and local effects, widespread showers and isolated thunderstorms will develop. From late tonight into Tuesday morning, showers will gradually increase from the Caribbean waters into the USVI and the southeastern sections of PR as the surge in moisture reaches the islands. In terms of hi-res guidance, the ECMWF ensemble has a more aggressive solution, with a larger convective footprint across the region and rainfall accumulations of 2 to 4 inches, mainly across SE and NW PR. At the same time, the NBM focuses shower activity on the same areas, but with lower amounts. Given the high PWAT environment and the potential for training cells, urban and small-stream flooding, along with localized mudslides in steep terrain, will become the main hazards. Shower activity will slowly taper off or become more localized by Wednesday as the bulk of the moisture plume shifts further west. However, lingering moisture and diurnal heating will still trigger afternoon convective development across the interior and western sections of Puerto Rico.

AVIATION

(18Z TAFS) Issued at 1250 PM AST Mon May 25 2026

Mainly VFR conditions are expected to prevail across all terminals. However, -SHRA from streamers may lead to brief MVFR conds at TJSJ this afternoon. There is a low chance for -TSRA to develop mainly in the vcty of TJBQ thru 25/22z. Strong E winds will continue at 18-22 kt with gusts near 30 kt through tonight.

MARINE

Issued at 1250 PM AST Mon May 25 2026

A strong high pressure over the central Atlantic continues to maintain a tight pressure gradient across the northeastern Caribbean. Small Craft Advisories remain in effect for the offshore waters through Tuesday night and for the local passages through at least Tuesday afternoon, as moderate to locally strong easterly winds continue to generate choppy to rough seas of up to 7 feet. During the second half of the week, conditions will gradually improve as winds subside to a gentle to moderate range. Mariners should also be aware of afternoon thunderstorms developing near the western coastal waters of Puerto Rico each day, which may produce locally higher winds and seas.

BEACH FORECAST

Issued at 1250 PM AST Mon May 25 2026

Breezy to windy conditions are maintaining a high risk of life- threatening rip currents across the northern, eastern, and southeastern beaches of Puerto Rico, as well as Vieques, Culebra, and the U.S. Virgin Islands through at least tomorrow, Tuesday. This means that life-threatening rip currents are likely in the surf zone. Therefore, a Rip Current Statement remains in effect. Beachgoers are urged to exercise caution and follow the advice of local officials and beach safety personnel.

Beginning midweek, the risk will slightly decrease as winds subside, but a moderate risk of rip currents will persist along northern and eastern exposed beaches. By next weekend, forecast guidance suggests increasing winds, which could cause the moderate risk to expand to most beaches.

Another beach hazard will be rapidly changing weather conditions and afternoon thunderstorms each day across western Puerto Rico. If thunder is heard, seek shelter immediately inside a building.

FIRE WEATHER

Issued at 1250 PM AST Mon May 25 2026

As anticipated, little to no rainfall has occurred across the southern sections of Puerto Rico today, and drier air is moving into the region, as indicated by satellite-derived PWAT imagery showing values of 1.5 inches or less. Relative humidity values have been in the upper 40s to low 50s along the southern coastal plains, with wind speeds of 16 to 25 mph and gusts up to 33 mph in the same areas. Therefore, conditions remain favorable for the spread of wildfires across the southern coastal plains of Puerto Rico, and the Fire Danger Statement (RFDSJU) remains in effect through this afternoon.

SJU WATCHES/WARNINGS/ADVISORIES

PR...High Rip Current Risk through Tuesday afternoon for PRZ001>003- 005-008-012-013.

Wind Advisory until 8 PM AST this evening for PRZ001>013.

VI...High Rip Current Risk through Tuesday afternoon for VIZ001-002.

Wind Advisory until 8 PM AST this evening for VIZ001-002.

AM...Small Craft Advisory until midnight AST Tuesday night for AMZ711- 712.

Small Craft Advisory until noon AST Tuesday for AMZ716-723-726- 733-741.