textproduct: San Juan

KEY MESSAGES

Issued at 133 PM AST Tue Jun 16 2026

* Mostly stable weather will continue tonight and Wednesday, with a brief increase in showers and isolated thunderstorms by Thursday.

* Warmer to hotter conditions will prevail for the rest of the week, particularly over urban areas and lower elevations of the islands.

* Breezy to locally windy conditions will continue across coastal areas of the islands for the next several days. Unsecured objects may blow around.

* Moderate concentrations of Saharan Dust will arrive by Thursday, bringing hazy skies, reduced visibility, and poor air quality.

Short Term(This evening through Thursday)

Issued at 133 PM AST Tue Jun 16 2026

Generally dry, stable, and breezy conditions will dominate across Puerto Rico and the U.S. Virgin Islands through Wednesday, before transitioning to a more moist but hazy atmosphere by Thursday. Through midweek, the primary weather impact will be an elevated fire weather threat, particularly across the southern, western, and central interior sections of Puerto Rico. This threat is driven by hot afternoon temperatures, critically dry fuels, and persistent easterly trade winds of 15 to 20 mph with stronger gusts in sea breeze variations. Outside of brief, fast moving windward showers and isolated induced afternoon convection over western PR, wetting rains will remain mostly limited.

By Thursday, a weak tropical wave will draw a small surge of low- level moisture into the region, resulting in a brief increase in shower frequency across the USVI and eastern sections of PR, and isolated afternoon thunderstorms over western PR. The main impact will shift to localized ponding of water in urban and poorly drained areas, with the highest potential for heavier showers focusing over the western and interior sections of PR. However, widespread flooding is not anticipated, as a moderate Saharan dust plume is forecast to spread across the islands simultaneously. This Saharan Air Layer will introduce hazy skies, degrade local air quality, and maintain enough dry air aloft to limit significant, long lasting showers and rainfall accumulations.

Long Term(Friday through next Monday)

Issued at 315 AM AST Tue Jun 16 2026

Dry and stable conditions remain on track for most of the long- term period following the passage of a tropical wave across Puerto Rico and the U.S. Virgin Islands. Moisture levels will gradually decrease from Friday into Sunday, falling below climatological normals for the season. This will be driven by strong surface high pressure over the central Atlantic, combined with a strengthening mid-level ridge over the region. At the upper levels, a lingering trough east-northeast of the area will gradually lift northward, losing its influence on the local weather pattern.

Meanwhile, moderate concentrations of Saharan dust are expected to arrive and persist through much of the period, resulting in hazy skies, reduced visibility, and degraded air quality across the islands. Residents and visitors, particularly those with respiratory sensitivities or allergies, should consider limiting prolonged outdoor exertion during periods of heavier haze.

By late Sunday into Monday, another tropical wave is expected to move south of the area. While the northern periphery of this wave could briefly enhance moisture across the region, no significant increase in shower activity or thunderstorm development is anticipated through midweek.

AVIATION

(18Z TAFS) Issued at 133 PM AST Tue Jun 16 2026

Mainly VFR conditions are expected to prevail across all terminals during the next 24 hours. However, brief SHRA expected to develop in and around TJBQ thru 16/22z, and once again fm 17/18-22z. Mostly VCSH expected across the rest of the terminals. The 16/12z TJSJ sounding indicated E-ESE winds btw 8-24 kt blo FL080.

MARINE

Issued at 133 PM AST Tue Jun 16 2026

A broad surface high pressure over the Central Atlantic will maintain breezy to locally fresh E-ESE winds for the next several days, resulting in choppy seas that may lead to hazardous conditions for small craft. Shower activity is expected to increase by Thursday as a tropical wave approaches the Caribbean Basin, likely to bring localized heavy rainfall, gusty winds, and reduced visibility. A dense layer of Saharan Dust should arrive by Thursday as well, bringing hazy skies, reduced visibility, and poor air quality.

BEACH FORECAST

Issued at 133 PM AST Tue Jun 16 2026

The beach forecast remains on track. The moderate risk of rip currents continues across the northern beaches of Puerto Rico, including Culebra, and St. Croix in the U.S. Virgin Islands; low elsewhere. Beachgoers should exercise caution, as life-threatening rip currents are possible along the beaches under moderate risk. The risk will gradually increase and spread across the islands as winds strengthen, with most beaches going under a moderate risk this Fathers Day weekend.

Besides rip currents, beachgoers are encouraged to remain weather alert, as afternoon showers and isolated thunderstorms can be expected for the rest of the workweek, which may move over coastal areas of northwestern Puerto Rico and bring wind gusts and lightning. Moderate concentrations of Saharan Dust will arrive by Thursday, resulting in hazy skies, reduced visibility, and poor air quality.

FIRE WEATHER

Issued at 133 PM AST Tue Jun 16 2026

An elevated fire weather danger will persist through Wednesday afternoon, primarily across the southern coastal plains and hills of Puerto Rico. A dry air mass, paired with intense daytime heating, will drive afternoon relative humidity down to near 50 percent or lower across these vulnerable areas. Concurrently, a tight pressure gradient will maintain breezy easterly trade winds averaging 15 to 20 mph with frequent stronger gusts. Given the combination of these gusty winds, low relative humidity, and above critical Keetch-Byram Drought Index (KBDI) values (751 in Cabo Rojo, 617 in Camp Santiago) reflecting critically dry vegetation, environmental conditions will remain highly favorable for rapid wildfire ignition and spread. Residents are strongly urged to avoid outdoor burning or any activities that could inadvertently generate sparks through midweek, as any fires that do ignite will be difficult to contain under these breezy, dry conditions.

A fire danger statement is in effect through late this afternoon for portions of southern, western, and central Puerto Rico.

SJU WATCHES/WARNINGS/ADVISORIES

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