textproduct: San Juan

KEY MESSAGES

Issued at 505 AM AST Wed Jan 14 2026

* Seasonal conditions will prevail across the region with passing trade-wind showers affecting the windward and coastal areas of Puerto Rico and the U.S. Virgin Islands during the morning and evening hours.

* A moderate risk of life-threatening rip currents will prevail along the north and east-facing beaches of Puerto Rico, Culebra and the U.S. Virgin Islands through Friday. Then, a high risk is anticipated Saturday and Sunday.

* Marine conditions will also deteriorate this weekend due to a northwesterly swell and stronger winds.

* Above-normal temperatures are expected over the next few days under a southeasterly wind flow.

Short Term(Today through Friday)

Issued at 505 AM AST Wed Jan 14 2026

Shower activity continued through the evening across northwestern Puerto Rico, where an extended period of rainfall resulted in amounts exceeding one inch. After midnight, activity transitioned to trade-wind showers moving inland from the local waters, affecting windward sections and producing rainfall totals near one-half inch across portions of eastern and northeastern Puerto Rico, including coastal areas of the San Juan metropolitan region. Overnight low temperatures so far have ranged from the upper 50s across higher elevations to the upper 70s across the U.S. Virgin Islands and surrounding islands. Winds over land have remained mostly light and variable.

A mid-level ridge, the dominant synoptic feature, lingering to the east will continue influencing the local environment today and tonight, maintaining subsidence aloft and a capped moisture profile initially below 700 mb. Early this morning, low-level moisture remains patchy rather than organized in a continuous plume, with land-breeze and trade-wind convergence occasionally pooling higher moisture along windward coastal areas, particularly across eastern Puerto Rico, enhancing passing showers across eastern Puerto Rico, Vieques, Culebra, and the U.S. Virgin Islands. PWAT values start the period modestly above normal (slightly above the the percentile) but are expected to drop rapidly to near seasonal levels by early afternoon as drier air mixes in. At the surface, high pressure over the North Atlantic will continue shifting eastward, maintaining a moderate east-southeast breeze today that will gradually veer toward the southeast over the next 1236 hours, providing a steady influx of low-level tropical moisture that will sustain trade-wind showers moving from the coastal waters inland and support afternoon, heating- and convergence-driven showers over northwestern Puerto Rico. Overall rainfall impacts are expected to remain limited, with only brief and very localized ponding possible in poor drainage areas. A warming trend will begin today under the prevailing east- southeasterly flow and ridge influence, resulting in above-normal daytime highs and potentially warmer-than-normal nighttime lows.

As the mid-level ridge lifts northeastward, deep tropical moisture will gradually expand across the region as the trade-wind cap weakens, peaking Friday afternoon before decreasing rapidly Friday night as drier air moves in. Warm air aloft will limit widespread thunderstorm development through most of the period; however, Friday afternoon will offer the most favorable window for deeper showers as mid-level temperatures briefly cool and daytime heating peaks, supporting enhanced shower activity over the interior and western portions of Puerto Rico, with an isolated thunderstorm possible. Winds are expected to weaken Thursday night into early Friday, allowing for slower-moving showers and localized flooding potential, then increase again later Friday while shifting from southeasterly to easterly and eventually east-northeasterly as a frontal boundary approaches and lingers northwest of the area. Shower activity will remain more frequent across eastern Puerto Rico on Thursday, then shift toward the interior and western sections on Friday. Overall flooding risk will remain localized; however, increasing wind speeds Thursday into Friday will elevate wind-related hazard risks, especially across exposed coastal and higher terrain areas. A warming trend will persist through most of the period, with some cooling suggested Friday night.

Long Term(Saturday through Wednesday)

Issued at 505 AM AST Wed Jan 14 2026

By Saturday, the interaction between a surface high-pressure system over the central Atlantic and a surface frontal boundary over the western Atlantic will tighten the pressure gradient, resulting in east to northeast breezy to locally windy conditions across the area. These winds may cause loose outdoor items to be blown around, particularly in exposed and coastal locations. Moisture content is expected to be below average during the early morning hours as a drier air mass, with precipitable water (PWAT) values around 1.10 inches, moves across the region. Moisture will gradually increase during the day, allowing for passing morning trade wind showers over windward areas and afternoon convection from the interior into western Puerto Rico. Passing showers across the U.S. Virgin Islands. However, activity should move quickly due to stronger winds, limiting rainfall accumulations and keeping the flood risk low.

On Sunday morning, winds will remain breezy but are expected to gradually weaken throughout the day. Sunday is anticipated to be the driest day of the period, with precipitable water values decreasing to between 1.2 and 1.5 inches and patches of near- average moisture moving across the region. These conditions will support more variable but seasonable weather, with passing trade wind showers and limited afternoon convective development due to local effects. From Monday through Wednesday, a subtropical jet streak near 250 mb will establish a more favorable dynamic pattern, supporting upper-level divergence and the development of an induced surface trough. As a result, an increase in shower activity is expected across the forecast area under an easterly to northeasterly low-level wind flow. The potential for isolated thunderstorms will also increase as mid to upper-level temperatures cool. Based on the latest model guidance, temperatures aloft are expected to decrease from around -5 degrees C on Monday to near -7.5 degrees C by Wednesday. Forecast updates should continue to be monitored as uncertainty remains. At this time, each afternoon from early to midweek carries a limited flood risk, mainly due to the potential for ponding of water on roads and in poorly drained areas.

Ensemble guidance continues to indicate above-normal surface temperatures across Puerto Rico and the U.S. Virgin Islands through the long-term period, at least from Saturday through Monday.

AVIATION

(06Z TAFS) Issued at 505 AM AST Wed Jan 14 2026

VFR conds will prevail across all TAF sites thru the fcst period. Periods of -RA/-SHRA will affect the USVI terminals and TJSJ thru 14/1314Z, with brief MVFR vsby/cigs psbl. Aft 14/1722Z, SHRA activity will shift inland, mainly impacting TJPS and TJBQ. After 14/22Z, SHRA will again affect the USVI and TJSJ. Sfc winds will be lgt/vrb early, incrg to 1015 kt and bcmg EESE btwn 14/1322Z, then returning to lgt/vrb thereafter. No sig or prolonged avn impacts fcst.

MARINE

Issued at 505 AM AST Wed Jan 14 2026

A surface high pressure across the central Atlantic will maintain gentle to moderate east to southeast winds through the end of the workweek. By Saturday, strengthening east to northeast winds, and the arrival of a long-period northerly swell will likely result in choppy to rough seas, leading to hazardous marine conditions during the weekend.

BEACH FORECAST

Issued at 505 AM AST Wed Jan 14 2026

A moderate risk of rip currents continues today along the northern and eastern beaches of Puerto Rico, as well as Culebra, St. Croix, St. Thomas, and St. John with breaking waves around 4 to 5 feet due to a small pulse of energy. The moderate risk will prevail through Friday, then conditions are likely to deteriorate Saturday afternoon through Sunday night as winds increase and a long- period northerly swell arrives. This may lead to a return of a high risk of rip currents across most local beaches of Puerto Rico and the U.S. Virgin Islands. For more location-specific information, continue to monitor weather.gov/beach/sju.

SJU WATCHES/WARNINGS/ADVISORIES

PR...None. VI...None. AM...None.