textproduct: San Juan

KEY MESSAGES

Issued at 145 PM AST Sat Jun 13 2026

* Warm-to-hot conditions will persist through Monday, with heat indices frequently ranging between 98 and 110F and locally higher in urban and coastal areas.

* Breezy east to east-southeast winds will continue, bringing occasional quick-moving showers to windward areas but limiting widespread rainfall.

* The best chance for showers will be overnight and in the morning across eastern and windward areas, and in the afternoon across western Puerto Rico and downwind of the U.S. Virgin Islands.

* A tropical wave will remain mostly south of the region, allowing drier-than- normal conditions and a limited flooding threat to continue through the short-term period.

* Life-threatening rip currents will remain possible along exposed beaches of Puerto Rico and the U.S. Virgin Islands through the forecast period. Beachgoers are urged to exercise caution and follow local beach safety guidance.

Short Term(This evening through Monday)

Issued at 145 PM AST Sat Jun 13 2026

Another relatively quiet day in terms of precipitation was observed across Puerto Rico and the U.S. Virgin Islands. However, above-normal temperatures persisted, with maximum temperatures reaching the mid-80s across the higher elevations and the upper 80s to low 90s along coastal and urban areas. Although the 12Z TJSJ sounding indicated drier-than-normal conditions, the combination of available low-level moisture and warm temperatures resulted in heat indices ranging from 98 to 105 degrees Fahrenheit, with locally higher values in urbanized and poorly ventilated areas. Winds remained from the east to east-southeast at 15 to 20 mph, with higher gusts and local sea breeze variations.

Warm-to-hot conditions will continue through the remainder of the afternoon and persist through the short-term period. Heat indices between 98 and 107 degrees Fahrenheit, and locally higher, will continue to pose a risk to sensitive individuals and vulnerable populations, particularly across northern and western Puerto Rico and the U.S. Virgin Islands.

Regarding rainfall, limited precipitation is expected. Breezy east-southeast winds will continue to transport small patches of moisture across the region, resulting in occasional passing showers across windward areas during the overnight and morning hours. During the afternoon, local sea breeze convergence and daytime heating may support isolated showers over western Puerto Rico and downwind of the U.S. Virgin Islands. Any rainfall activity should be brief and fast-moving, resulting in a minimal flooding threat.

A tropical wave moving across the Caribbean Sea is forecast to remain well south of Puerto Rico and the U.S. Virgin Islands through Sunday, approaching the region more closely by Monday. However, the deepest moisture associated with this feature is expected to remain south of the local islands, allowing drier- than-normal conditions to prevail. Therefore, the overall weather pattern will continue to favor breezy east-southeast winds, above- normal temperatures, and generally limited rainfall through the forecast period.

Long Term(Tuesday through Saturday)

Issued at 340 AM AST Sat Jun 13 2026

Surface high pressure will maintain brisk winds out of the east- southeast through the next weekend. At the mid levels, a high is also responsible for low relative humidities values and stable conditions aloft. An upper level high will also move high clouds from the Caribbean into the local islands, further hindering the development of showers into the islands. Through at least Thursday, expect limited shower activity, but local effects will trigger localized showers along western Puerto Rico, where ponding of water cannot be ruled out.

By the end of the week, an upper level low will develop northeast of the islands, finally increasing instability aloft, with 500 mb temperatures cooling down. This feature will combine with low level moisture from a tropical wave or surface trough to increase the potential of showers along the Virgin Islands and eastern Puerto Rico through the day, and across western Puerto Rico in the afternoon. It is worth mentioning that there are some factors that could work against a rainfall forecast, such as the position of the upper level trough, the intrusion of mid-level dry air, Saharan dust and high clouds reducing the amount of solar radiation. The user should stay tuned as the forecast evolves Regardless, any rain would be beneficial for areas experiencing abnormally dry or moderate drought conditions in Puerto Rico and the Virgin Islands.

By the weekend, the upper level low lift toward the north and the air mass will become stable once again. In fact, moderate concentrations of Saharan dust are anticipated, resulting in hazy skies.

AVIATION

(18Z TAFS) Issued at 145 PM AST Sat Jun 13 2026

Mainly VFR conditions will prevail throughout the forecast period. VCSH may affect TJBQ between 13/19Z and 20Z. The primary aviation concern will be the breezy to windy conditions. East- southeast winds of 14 to 20 kt, with gusts up to 30 kt and local sea breeze variations, will persist through 13/22-23Z before diminishing to 10 kt or less overnight. Low to moderate concentrations of haze (HZ) will continue across the region and may result in minor visibility reductions.

MARINE

Issued at 145 PM AST Sat Jun 13 2026

A strengthening surface high pressure over the central Atlantic will maintain fresh trade winds and choppy marine conditions through at least next Monday. Seas are expected to range between 4 and 6 feet, occasionally higher, across the regional waters and local passages. Small craft operators should exercise caution as seas build and trade winds strengthen. By Tuesday, winds are expected to decrease to moderate to locally fresh levels, with seas subsiding to 3 to 5 feet. Hazy skies associated with low to moderate concentrations of Saharan dust will persist throughout the forecast period.

BEACH FORECAST

Issued at 145 PM AST Sat Jun 13 2026

Breezy to windy conditions will maintain a moderate risk of rip currents across most beaches of Puerto Rico, as well as Culebra, Vieques, and the U.S. Virgin Islands through the weekend and into next week. Life-threatening rip currents remain possible, and beachgoers are urged to exercise caution, swim near lifeguards, and follow the guidance of local beach patrols and flag warning systems.

A low risk of rip currents will persist along the western beaches of Puerto Rico. However, dangerous rip currents can still occur even when the risk is low, particularly near groins, jetties, reefs, and piers. For more information, visit weather.gov/beach/sju.

FIRE WEATHER

Issued at 145 PM AST Sat Jun 13 2026

For the remainder of today, a limited fire weather risk is expected across southern Puerto Rico and the U.S. Virgin Islands. However, breezy east-southeast winds, low relative humidity values near or below critical thresholds, and increasingly dry fuels will continue to elevate fire weather concerns over the next few days.

The ongoing drying of vegetation and fine fuels will favor wildfire ignition and rapid spread, particularly across Puerto Rico's southern coastal plains.

SJU WATCHES/WARNINGS/ADVISORIES

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