textproduct: San Juan

KEY MESSAGES

Issued at 300 AM AST Wed Jun 17 2026

* Mostly stable weather today, then periods of showers and thunderstorms Thursday into Friday, and again late weekend into early next week. Localized flooding possible in stronger storms.

* Hot conditions will continue through the period, with highest heat impacts in the afternoons across urban and low-lying areas.

* Elevated wildfire risk today due to dry, hot, and breezy conditions, with additional risk possible during drier periods between tropical waves.

* Saharan dust increases late in the week, bringing hazy skies and reduced air quality.

* Exposed beaches will see a moderate risk of rip currents today, with the risk increasing late in the week into the weekend as winds strengthen. Choppy seas will continue through the period.

Short Term(Today through Friday)

Issued at 300 AM AST Wed Jun 17 2026

A generally stable weather pattern will persist through tonight as a drier air mass gradually builds into the region. Brief passing showers will remain possible across windward areas, while lingering moisture ahead of the drier air mass may support isolated showers and thunderstorms across western and interior Puerto Rico this afternoon. Any thunderstorms that develop could produce locally heavy rainfall, resulting in ponding of water on roads and very localized flooding impacts.

Moisture associated with a weak tropical wave will increase across the region Thursday into Friday. However, moisture levels are expected to remain near seasonal normals, while persistent dry air aloft and a moderate Saharan dust plume will limit rainfall coverage and intensity. As a result, showers and isolated thunderstorms will remain possible, particularly during the afternoon hours, with localized flooding possible following thunderstorm development but widespread flooding not anticipated.

The primary concern today will be an elevated fire weather risk across southern and western Puerto Rico due to dry fuels, hot temperatures, low humidity values, and breezy easterly winds. Additional hazards through the period will include heat, breezy to locally windy conditions, limited lightning and localized flooding impacts, and increasing haze late in the week. Heat impacts may become more noticeable Thursday and Friday as moisture levels increase.

Long Term(Saturday through Wednesday)

Issued at 300 AM AST Wed Jun 17 2026

Over the weekend, a broad surface high-pressure system over the central Atlantic will maintain a typical easterly trade wind pattern across the northeastern Caribbean. A relatively dry air mass and intermittent intrusions of Saharan dust will support generally stable weather conditions, hazy skies at times, and warm to locally hot daytime temperatures. Passing showers embedded within the trade wind flow will continue, mainly across windward areas, but rainfall accumulations are expected to remain light.

By early to mid next week, moisture associated with a tropical wave will increase across the region, resulting in a more humid and unsettled pattern. This will support periods of showers and isolated thunderstorms, especially during the afternoon hours across portions of western and interior Puerto Rico. While a few locally heavy showers cannot be ruled out, widespread hazardous weather is not expected.

Thereafter, a gradual return to a drier air mass is expected as the Atlantic ridge reestablishes a typical trade wind pattern. This will favor generally fair and warm conditions with passing showers embedded in the easterly flow and limited afternoon convection.

The primary hazards through the long-term period will include periods of elevated heat, occasional Saharan dust intrusions, strengthening trade winds at times, and localized impacts from isolated showers and thunderstorms.

AVIATION

(06Z TAFS) Issued at 300 AM AST Wed Jun 17 2026

Mainly VFR conditions will prevail at all TAF sites through the forecast period. VCSH with brief -SHRA is possible near TJSJ through 17/14Z, with VCTS near TJBQ between 17/17Z-20Z and VCSH across USVI terminals after 17/21Z. Light Saharan dust will maintain locally hazy skies with minimal VIS impacts. E winds will increase to 15-20 kt with higher gusts and sea-breeze variations between 17/14Z-23Z, becoming 10 kt or less overnight.

MARINE

Issued at 300 AM AST Wed Jun 17 2026

Breezy to locally fresh east to east-southeast winds will maintain choppy seas through the period. Small craft should exercise caution. Winds may strengthen further Thursday into Friday as a tropical wave moves through the eastern Caribbean. Showers and isolated thunderstorms may also increase, with lightning, gusty winds, and locally hazardous seas possible near thunderstorms. Saharan dust arriving Thursday will result in hazy skies and reduced visibility at times.

BEACH FORECAST

Issued at 300 AM AST Wed Jun 17 2026

A low to moderate risk of rip currents will persist through the next several days, with moderate risk beaches mainly along the north coast of Puerto Rico and exposed east-facing beaches of the local islands. The moderate risk will expand late in the week as east to east-southeast winds strengthen. Beachgoers should also remain alert for dangerous lightning near isolated thunderstorms. Saharan dust arriving Thursday afternoon will result in hazy skies and reduced air quality, while elevated heat indices will continue through the period.

FIRE WEATHER

Issued at 300 AM AST Wed Jun 17 2026

A Fire Danger Statement has been issued for today, with the greatest fire danger expected from the late morning through the afternoon across portions of southern Puerto Rico. While some uncertainty remains regarding the timing of the driest air, conditions are expected to become progressively drier during the next 6 to 12 hours. Combined with hot temperatures, breezy easterly winds, and critically dry fuels, any fire that develops could spread rapidly.

Fire weather conditions are expected to fluctuate during the next several days as tropical waves move through the region Thursday into Friday and again Sunday into Monday. While these systems may bring periods of showers, rainfall is expected to remain localized and unlikely to provide widespread relief to dry fuels, particularly across the most fire-prone areas. Between these waves, drier air and breezy conditions may support periods of elevated fire danger across portions of Puerto Rico.

SJU WATCHES/WARNINGS/ADVISORIES

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