textproduct: San Juan

KEY MESSAGES

Issued at 158 PM AST Fri Nov 13 2026

- Breezy conditions will persist for the rest of today and tomorrow across the U.S. Virgin Islands and Puerto Rico. Unsecured items may blow around.

- Hot and humid conditions will persist across the islands over the next few days. Sensitive individuals should remain hydrated and seek indoors during peak daytime heating hours.

- Moisture content at low-levels, diurnal heating and local effects could still support brief showers and thunderstorm development over the next few days each afternoon over southern and northwestern PR.

- A moderate risk for life-threatening rip currents will continue through Monday across most local beaches, improving gradually by Monday onwards.

Short Term(This evening through Sunday)

Issued at 158 PM AST Fri Nov 13 2026

Fair weather has prevailed across the islands this afternoon, though breezy conditions ramped up earlier today, with weather stations over the mountainous regions of Puerto Rico recording wind gusts up to 40 mph. A surface high-pressure system over the central Atlantic will continue to tighten the local pressure gradient, promoting a breezy south-southeast wind flow today and tomorrow that may blow around unsecured items. Consequently, while low- level moisture will remain at seasonal levels over the next two days, these brisk winds will limit high rainfall accumulations through at least tomorrow. Mid-level subsidence driven by a ridge will further suppress deep convection during the weekend, however, diurnal heating and local effects may trigger isolated activity. As a result, the most likely scenario today into the weekend consists of shallow, short-lived showers and isolated thunderstorms each afternoon. This activity will focus primarily over southern and northwestern Puerto Rico, alongside possible passing morning showers across windward sections tomorrow. Because these showers will be fast-moving, rainfall accumulations are expected to remain at or below half an inch. On Sunday, although the wind flow speed will slightly decrease, continued mid-level subsidence and precipitable water values dropping below-seasonal values (1.001.40 inches) will promote mostly fair weather, though isolated, brief shower activity cannot be ruled out.

Given these conditions, the primary concern over the next several days and into early next week will be heat-related risks. Above- normal 925 mb temperatures exceeding two standard deviations above average, limited cloud cover, and seasonal low-level moisture today and tomorrow will combine to create hot and humid conditions, pushing heat indices to levels capable of affecting most heat- sensitive individuals. While breezy winds today and tomorrow may help temper peak heat indices, particularly across interior portions of Puerto Rico, heat risks will expand across most of the CWA over the weekend. Therefore, heat-sensitive individuals are encouraged to stay hydrated and seek cooler environments during peak daytime heating hours.

Long Term(Monday through next Thursday)

Issued at 435 AM AST Fri Nov 13 2026

Next week's weather will be influenced by intermittent easterly disturbances dragging pulses of moisture into the islands until Wednesday, which will maintain moisture content at seasonal to above- seasonal levels by the first half of the week. However, a persistent mid-level ridge over the central Atlantic Ocean will promote subsidence at the mid-levels which may be a limiting factor to deeper convection. The first pulse of moisture should arrive on Monday morning, which will enhance showers across windward sections and localized afternoon convection over the interior to western portions of Puerto Rico driven by a gentle to moderate easterly wind flow. Lingering moisture on Tuesday will promote a similar pattern. Winds are forecasted to change to a more ESE flow by Wednesday onwards, promoting shower and thunderstorm development towards northwestern portions of Puerto Rico. On Thursday morning, a patch with less moisture content should reach the CWA, nonetheless, moisture content should remain at seasonal levels. Seasonal moisture in the low-levels, diurnal heating and topographic effects could promote activity towards the northern and northwestern portions of Puerto Rico. This scenario will maintain a slight risk of flooding until Wednesday. Hence, a threat of ponding of water over roadways and poorly drained areas, along with isolated urban and small stream flooding will be present during the first half of the work week.

AVIATION

(18Z TAFS) Issued at 158 PM AST Fri Nov 13 2026

Mainly VFR conds expected across all terminals thru the fcst period, with no sig wx impacts anticipated. SE-S winds at 10-15 kt with sea breeze variations and gusts up to 18-24 kt thru 13/22-23Z. Winds bcmg lighter overnight, then incr aft 14/13-14Z with gusts up to 20- 23 kt.

MARINE

Issued at 158 PM AST Fri Nov 13 2026

A surface high-pressure extending from the east to the central Atlantic Ocean is promoting a fresh to strong SSE breeze across the local waters. This will lead to choppy to locally high seas from today into Saturday. By Sunday the SSE breeze will become moderate to locally fresh and lead to moderate to choppy seas. With significant wave heights ranging from 3-6 feet and occasionally reaching 7 feet across the offshore waters and local passages. Conditions will gradually improve into early next week but will still remain breezy. Showers and thunderstorm activity may produce locally higher winds and seas.

BEACH FORECAST

Issued at 158 PM AST Fri Nov 13 2026

Wind driven seas are leading to a moderate risk of life-threatening rip currents along the majority of the beaches of Puerto Rico and the U.S. Virgin Islands. This level of threat will persist into the remainder of the forecast period. Nonetheless, conditions will improve in the beaches of the U.S. Virgin Islands and western Puerto Rico by Sunday, and for southern Puerto Rico and Vieques by early next week.

Beachgoers should exercise caution when swimming at the beach and remain updated with the latest forecasts as they become available. While showers and thunderstorms will be less likely over the weekend along the CWA localized showers and thunderstorms especially along the western and northwestern beaches of Puerto Rico during the afternoons. If you hear thunder seek shelter immediately. Remain weather ready and alert with the latest forecasts as they become available.

SJU WATCHES/WARNINGS/ADVISORIES

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