textproduct: San Juan

KEY MESSAGES

* Showers and isolated thunderstorms are expected each day, mainly over western Puerto Rico in the afternooneven on drier days. Flooding risk will likely increase Sunday through Tuesday due to higher moisture and instability.

* Breezy to locally windy conditions will continue over the next few days, causing choppy seas and a moderate risk of life- threatening rip currents along most beaches.

* Moderate to high concentrations of Saharan dust will persist through Thursday morning, with lighter dust lingering into Friday, resulting in hazy skies and reduced visibility and air quality.

* Fire danger risks may increase by the end of the workweek, as drier conditions develop across the region.

LONG TERM...Saturday through Wednesday

A mid-level ridge will dominate through Saturday, promoting dry air entrainment and keeping moisture levels below normal, with precipitable water (PWAT) values under 1.6 inches. As the ridge weakens, an upper-level trough will deepen and organize into a closed low west of the region by late weekend. This will increase instability and draw in additional moisture, briefly pushing PWAT above 2.0 inches early next week.

At the surface, a broad high pressure system will support moderate to locally fresh easterly to east-southeasterly winds, resulting in breezy to locally windy conditions, especially along the coast and exposed areas. Temperatures will be near normal Saturday, dip slightly on Sunday, then trend above normal through midweek due to warmer low-level air and more southeasterly flow.

Rainfall activity will remain limited Saturday but is expected to increase Sunday into Tuesday as the combination of deeper moisture and instability favor more organized showers and isolated thunderstorms, mainly over western to northwestern and eastern Puerto Rico. Urban and small stream flooding, along with localized flash flooding, will be possible in areas of heavier rainfall. By midweek, conditions should return to more typical shower pattern; however, this will depend on how long the upper- level low lingers before shifting eastward and away from the region.

Overall, elevated risk for excessive rainfall and localized flooding is likely Sunday into Tuesday, with excessive heat, breezy conditions, and lightning impacts also possible at times.

AVIATION

(06Z TAFs)

Mainly VFR conditions across most terminals are expected, however -RA and VCSH will likely impact TJSJ and USVI terminals over the next hours. Additional activity is possible near TJBQ area between 11/17-23Z. These may lead to intermittent/brief MVFR conditions. Saharan dust concentrations will maintain hazy skies, with visibility occasionally reduced to 56 SM. The other main aviation concern will be the increasing winds to 1520 kt with higher gusts after 11/13Z to 11/14Z, then gradually diminishing during the evening hours.

MARINE

A broad surface high pressure system over the North Atlantic will continue to promote moderate to locally fresh easterly winds, leading to choppy seas across most local waters and the Caribbean passages. Small craft should exercise caution. These conditions are expected to persist through the remainder of the workweek and into the weekend. Isolated afternoon thunderstorms may develop each day, mainly affecting the northern and western coastal waters of Puerto Rico.

BEACH FORECAST

Breezy to locally windy conditions are expected along coastal areas, especially at exposed spots, contributing to a moderate risk of life-threatening rip currents. While non-exposed western beaches will have a lower rip current risk, isolated stronger currents may still develop near piers, jetties, and channels. In terms of weather, morning showers are likely across eastern Puerto Rico, followed by isolated thunderstorms in the northern and western coastal areas during the afternoon. Beachgoers should remain cautiousswim near lifeguards, avoid strong currents, and stay alert to gusty winds and changing weather. For the latest information, please refer to the Surf Zone Forecast (SRFSJU).

FIRE WEATHER

Southern Puerto Rico continues to experience significant dryness, with the Keetch-Byram Drought Index (KBDI) exceeding 550indicating dry and receptive fuels in fire-prone areas. In addition, 30- and 60-day rainfall deficits reflect ongoing drying trends across the region. Breezy winds around 15-20 mph, with gusts over 25 mph, could contribute to fire spread if an ignition occurs. However, relative humidity values are expected to remain above critical thresholds, helping to limit the overall fire danger. Taking all factors into account, fire danger remains low today, but may increase on Thursday due to potentially drier conditions.

SJU WATCHES/WARNINGS/ADVISORIES

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