textproduct: San Juan

KEY MESSAGES

Issued at 230 AM AST Fri Aug 14 2026

- Heat Risk is elevated today, with a Heat Advisory in effect. Risk may decrease over the weekend, then increase again early next week, potentially becoming significant by midweek.

- Dry and breezy to locally windy conditions will support elevated fire danger today, with a Fire Danger Statement in effect. The dry and windy pattern will persist into early in the weekend.

- Marine and coastal hazards are ongoing and will remain through Sunday. Additional extensions may be needed with the influence of AL92, followed by gradual improvement early next week.

- Moisture associated with Invest 92L will increase across the region Saturday night into Sunday, enhancing showers and isolated thunderstorms. Uncertainty remains, with latest guidance continuing to keep the bulk of the rainfall south of the local islands.

Short Term(Today through Sunday)

Issued at 230 AM AST Fri Aug 14 2026

Strong high pressure north-northeast of the region will maintain a tight pressure gradient and increasingly easterly flow today, pushing a drier air mass across the northeastern Caribbean. Precipitable water (PWAT) will decrease to around 1 inch, below climatological values, while very dry mid-level air and a strong trade-wind inversion suppress convection. Therefore, rainfall will remain very limited through much of Saturday. Lower Saharan dust concentrations will linger, but visibility should gradually improve. Breezy to locally windy conditions will persist, with 925 mb winds remaining above climatology. Abundant sunshine and anomalously warm low-level temperatures will support elevated heat risk today, with a Heat Advisory in effect. Separately, low relative humidity, dry fuels and soils, and strong easterly winds will favor rapid fire spread, particularly across the southern coastal plain and adjacent slopes of Puerto Rico. A Fire Danger Statement will also be in effect.

Moisture will increase Saturday night into Sunday as Invest 92L and its moisture field approach the eastern Caribbean. The National Hurricane Center maintains a medium formation chance during the next 2 and 7 days, although AL92 has become less organized while encountering stronger upper-level winds and drier air. Latest guidance generally favors AL92 moving into the eastern Caribbean as an open wave, with the deepest moisture and bulk of the rainfall remaining south of the local islands over the Caribbean waters. Still, PWAT should rise to around 1.7 to 1.8 inches Sunday, favoring overnight and morning windward showers and isolated thunderstorms, followed by locally induced afternoon convection across Puerto Rico. Locally heavy rain, lightning, and gusty winds are possible with the strongest activity, but widespread rainfall is not expected. If current guidance verifies, Sunday should resemble an enhanced seasonal convective pattern rather than a widespread heavy-rainfall event.

Long Term(Monday through Friday)

Issued at 230 AM AST Fri Aug 14 2026

Variable conditions are expected through the period, with generally east to east-southeast winds and increasing uncertainty late next week. On Monday, moisture trailing AL92 may support passing windward showers and afternoon thunderstorms across western Puerto Rico. Another increase in Saharan dust is also possible. A trade-wind perturbation may pass late Monday into Tuesday, but latest guidance keeps most of its activity north of the islands. Ponding of water and localized minor flooding remain possible with heavier afternoon showers.

A more seasonal pattern is expected Tuesday through Thursday as PWAT gradually increases to 1.5 to 1.7 inches. An upper-level low will also cool 500 mb temperatures to around -6 to -7 degrees C, increasing instability. Nighttime and morning windward showers will be followed by afternoon showers and isolated thunderstorms across interior and western Puerto Rico, particularly Tuesday and Wednesday. The flood threat should remain limited, mainly involving ponding of water, although localized urban and small-stream flooding cannot be ruled out.

Forecast uncertainty increases Thursday into Friday as the National Hurricane Center monitors AL94 southwest of the Cabo Verde Islands. Global guidance generally brings the system toward the northeastern Caribbean late next week, but differences remain in timing and intensity, including whether development occurs before the system encounters a less favorable environment. Continue to monitor the latest NHC forecasts.

AVIATION

(06Z TAFS) Issued at 230 AM AST Fri Aug 14 2026

Mainly VFR conds expected. HZ from Saharan dust will gradually diminish with improving VIS. No SHRA/TSRA expected at the terminals. E winds 10-15 kt overnight, increasing aft 14/13-14Z to 20-25 kt with gusts 30-35 kt, then diminishing again after sunset.

MARINE

Issued at 230 AM AST Fri Aug 14 2026

A tight pressure gradient will maintain fresh to locally strong easterly winds and choppy to hazardous seas around 7 feet, with occasional seas of 8 to 9 feet across the offshore waters and local passages. Small Craft Advisories remain in effect through at least Sunday. Showers and thunderstorms will increase Sunday into Monday as AL92 passes south of the region, with the Caribbean waters and southern portions of the local passages most affected.

BEACH FORECAST

Issued at 230 AM AST Fri Aug 14 2026

Strong trade winds and choppy to hazardous seas will maintain a high risk of life-threatening rip currents along most beaches of Puerto Rico, Vieques, Culebra, and the U.S. Virgin Islands through the weekend. Rip Current Statements remain in effect through late Saturday night. Protected western Puerto Rico beaches should remain at a moderate risk.

Beachgoers should swim near lifeguards and follow beach patrol flags and posted signs. Breezy to windy conditions may also blow around unsecured tents, chairs, and umbrellas.

FIRE WEATHER

Issued at 230 AM AST Fri Aug 14 2026

Elevated fire danger is expected today as low relative humidity, dry fuels and soils, and strong easterly winds favor rapid fire spread, particularly across the southern coastal plain and adjacent slopes of Puerto Rico. A Fire Danger Statement will be in effect.

Dry and breezy conditions will continue through much of Saturday before increasing moisture Saturday night into Sunday raises relative humidity and reduces fire weather concerns.

SJU WATCHES/WARNINGS/ADVISORIES

PR...High Rip Current Risk from 6 AM AST this morning through late Saturday night for PRZ001>003-005-007-008-011>013.

Heat Advisory from 10 AM this morning to 6 PM AST this evening for PRZ001>005-007-008-010>013.

Fire Danger Statement from 10 AM this morning to 6 PM AST this evening for PRZ014>019-022>027.

VI...High Rip Current Risk from 6 AM AST this morning through late Saturday night for VIZ001-002.

Heat Advisory from 10 AM this morning to 6 PM AST this evening for VIZ001-002.

Fire Danger Statement from 10 AM this morning to 6 PM AST this evening for VIZ001-002.

AM...Small Craft Advisory until 5 PM AST Sunday for AMZ711-723-733- 741.

Small Craft Advisory from 6 AM this morning to 1 PM AST Saturday for AMZ712-716-726-735.