textproduct: San Juan

KEY MESSAGES

Issued at 142 AM AST Tue Feb 24 2026

* Shower and thunderstorm activity expected to increase this afternoon across the interior of Puerto Rico, where there is an elevated flood threat.

* Across the USVI, passing showers will increase early this morning, with a drying trend expected on Wednesday.

* A long period northwesterly swell will bring hazardous seas, life-threatening rip currents and high surf conditions from Wednesday through at least Friday. Continue to monitor the forecast in the coming days and heed the advice of lifeguards, flags and signs.

* Minor concentrations of Saharan dust are expected to filter late tonight.

Short Term(Today through Thursday)

Issued at 142 AM AST Tue Feb 24 2026

A col area north of the region and a developing pre-frontal trough will bring a surge in low-level moisture today, with precipitable water content increasing around 1.75 inches by this afternoon. At the upper levels, a trough will promote colder 500 mb temperatures around -8.5C through at least Wednesday. Therefore, expect showers to increase in coverage and intensity, with isolated thunderstorm development. There is an elevated flood threat(urban and small stream flooding, with possible isolated flash flooding) for most of the interior and western sections of PR today, and a limited flood threat across the USVI, Vieques, Culebra, and the eastern portions of PR, where ponding of water on roads and minor flooding is possible. On Wednesday, although moisture content will fluctuate around climatology (1.40-1.70 inches), a drier air mass with minor concentrations of Saharan dust will filter from the east overnight and through the early morning hours, and limit shower activity gradually across the USVI and eastern sections of PR. However, the available moisture content, combined with daytime heating and local effects will trigger shower and isolated thunderstorm activity over western PR in the afternoon hours. Gusty winds and locally heavy rainfall is possible with this activity. Meanwhile, a surface high pressure strengthening over the Central Atlantic, will promote moderate to locally fresh easterly winds and bring low-level clouds and passing showers from the Tropical Atlantic into the local area through Thursday. Rainfall totals on Thursday should not cause flooding concerns due to the fast moving nature of the showers, and as an overall drier air mass remains in place, with PWAT dropping below climatology.

Daytime temperatures will drop around 2-4 degrees compared to yesterday as showers increase today, and the stronger trades (15-20 knots) return through the rest of the short-term period. Highs are forecast to range from the mid 80s to the upper 80s across the lower elevations, to the mid 70s across the higher elevations.

Long Term(Friday through Tuesday)

Issued at 142 AM AST Tue Feb 24 2026

A broad surface high pressure system across the Central Atlantic will be the dominant weather feature for most of the period across the forecast area. This system will promote moderate to locally fresh easterly winds on Friday. Under this wind pattern, patches of shallow moisture with precipitable water values from 1.4 to 1.7 inches will move across the islands, enhancing cloudiness and supporting a showery pattern, especially across the U.S. Virgin Islands and eastern Puerto Rico during the morning hours. On Saturday, a slight variation in the wind pattern is forecast, with winds veering as the surface high interacts with an induced pre- frontal trough over the western Atlantic and its associated frontal boundary. This interaction will maintain moderate southeasterly winds from Saturday through Monday. Therefore, the islands can expect persistent patches of shallow but sufficient moisture to sustain a variable and showery weather pattern during this period. Morning showers are expected across portions of the U.S. Virgin Islands, followed by afternoon convection, particularly across the northwestern quadrant of Puerto Rico and the San Juan metropolitan area, aided by showers developing near the El Yunque region in streamers. Although showers may be locally significant, especially in the afternoon, widespread flooding is not anticipated. Minor flooding may occur in low-lying and urban areas. Breezy conditions are also expected, as suggested by 925 mb winds ranging between 18 and 20 knots.

By Tuesday, an increase in surface moisture is forecast as a frontal boundary approaches north of the islands, with associated cloudiness and moisture slightly above the climatological normals reaching the northern sections of Puerto Rico. The approach of this system will promote a more pronounced easterly wind pattern across the region. As a result, showers are expected across eastern Puerto Rico and along the north and northeast coasts. Residents and visitors are urged to stay tuned for further updates.

AVIATION

(06Z TAFS) Issued at 142 AM AST Tue Feb 24 2026

Mainly VFR early in the fcst period across all terminals. SHRA/TSRA expected to develop along the interior and western PR btw 24/16-22z. This may cause tempo MVFR conditions across the PR terminals, and mtn tops obscd. Low-level winds expected E-ESE up to 12 kt with a northerly component at TJBQ/TJSJ from late this morning through the mid-afternoon hours due to the sea breeze.

MARINE

Issued at 142 AM AST Tue Feb 24 2026

An approaching front from the western Atlantic and a developing pre-frontal trough will promote light and variable winds today across the Atlantic waters and the Mona Passage. Shower activity and the potential for isolated thunderstorms will increase from this afternoon through tonight. A long-period north-northwesterly swell is expected to spread across the Atlantic waters and passages from late tonight into Wednesday morning, building seas between 6 and 9 feet. Hazardous seas are expected to linger through Friday, and Small Craft Advisories are in effect. Moderate to fresh trades will return during the second part of the workweek, as surface high pressure builds over the Central Atlantic.

BEACH FORECAST

Issued at 142 AM AST Tue Feb 24 2026

A moderate risk of rip currents will continue along the north and east-facing beaches of Puerto Rico, including Culebra and Vieques, as well as St. Thomas, St. John, and St. Croix. Be aware that life- threatening rip currents can occur, especially in exposed beaches near rocks, piers, and jetties.

A long-period northwesterly swell will arrive late tonight into early Wednesday morning, peaking between Wednesday evening and early Thursday morning. This will increase the risk of rip currents to high, beginning Wednesday morning, with hazardous conditions (high surf, minor beach erosion, and life-threatening rip currents) expected through Friday.

For safety, always check local conditions before swimming. Beach goers and unexperienced surfers are urged to avoid beaches exposed to the northerly swell. Remember to swim near a lifeguard, never swim alone, and, if caught in a rip current, stay calm and float rather than fight it.

SJU WATCHES/WARNINGS/ADVISORIES

PR...None. VI...None. AM...Small Craft Advisory from 6 AM Wednesday to noon AST Friday for AMZ711-712-716-723-741-742.