textproduct: San Juan

KEY MESSAGES

Issued at 306 AM AST Wed Nov 11 2026

- Morning passing showers across eastern Puerto Rico, followed by locally induced afternoon showers over northwestern Puerto Rico today.

- Across the U.S. Virgin Islands, mainly fair weather conditions are expected. - Southeasterly to southerly winds will promote warm to hot conditions over the coming days. Sensitive individuals should remain hydrated and limit sun exposure during peak heat hours.

- There is a moderate risk of rip currents along northern and eastern beaches of Puerto Rico, Culebra, Vieques, and the U.S. Virgin Islands. Remain cautious as life-threatening rip currents are possible.

Short Term(Today through Friday)

Issued at 306 AM AST Wed Nov 11 2026

Fair weather conditions were present during the overnight period with mostly clear skies. Surface observations registered minimum temperatures into the mid 70s to low 80s across coastal areas and into the 60s to low 70s across the mountainous regions. Winds remained mainly light and variable.

Surface high pressure across the western and central Atlantic will maintain a moderate southeast to south wind flow across the region over the coming days. Model guidance suggests precipitable water values will fluctuate between approximately 1.70 (today) and 2.10 inches (mainly on Thursday), remaining near normal to slightly above normal based on climatology for the month of November. Although a building ridge aloft will promote generally stable conditions and drier air in the middle and upper levels, sufficient low-level moisture will remain across the region to support passing showers. Weak low-level perturbations embedded within the prevailing flow may also contribute to occasional increases in shower activity.

Today, expect passing showers across the U.S. Virgin Islands and the eastern and southeastern coastal sections of Puerto Rico during the overnight and early morning hours. During the afternoon, daytime heating, local effects, and sea breeze convergence will favor shower development across the interior and western to northwestern portions of Puerto Rico. While widespread organized convection is not anticipated, locally heavy rainfall will remain possible. By Thursday afternoon and Friday, moisture content slightly increases, not only at the surface but in the 850 to 500 mb levels. The frequency of trade wind passing showers will likely increase Thursday night along the Caribbean waters into southeastern portions of Puerto Rico. Therefore, isolated urban and small stream flooding, along with minor water accumulation on roadways, cannot be ruled out, particularly Thursday and Friday across the northwestern and southeastern portions of Puerto Rico.

At the surface, generally warm to hot conditions are expected across the islands. Forecast 925-mb temperatures indicate warm low-level air persisting throughout the period, supporting daytime temperatures above seasonal averages in some areas, particularly across coastal and urban locations. Combined with periods of sunshine and the prevailing southeasterly flow, these conditions may contribute to elevated heat indices during the afternoon hours, primarily affecting those who are particularly sensitive to heat. Remember to remain hydrated.

Long Term(Saturday through Wednesday)

Issued at 306 AM AST Wed Nov 11 2026

The forecast remains predominantly on track. Model guidance indicates that a surface high pressure over the east-to-central Atlantic will maintain a calm-to-breezy SSE to SE wind flow across the islands through Sunday. As the high pressure recedes further into the eastern Atlantic Ocean the winds will shift to be calm and from the ENE on Monday. On Tuesday a developing surface low- pressure system to the NW of the islands will again shift the direction of the winds to be predominantly from the ESE. Available moisture will reduce into the long-term period across the CWA as precipitable water (PWAT) and column relative humidity values remain below seasonal levels acting as a limiting factor for the development of convection. Another inhibiting factor for the development of deep convective cells will be a mid-level ridge over the eastern Caribbean. This high-pressure will warm temperatures above -6 degrees Celsius (probability of exceedance of around 70% each day) and consequently weaken the lapse rates at these levels. These conditions will lead to subsidence and stability above. Nonetheless, available moisture along with local effects (i.e., sea-breeze convergence, orographic effects and diurnal heating) will lead to the development of showers and thunderstorms each afternoon with a focus along the northern interior, western interior, and northwestern regions of Puerto Rico during the afternoons. Advective showers during the mornings and nights and streamers from El Yunque and the smaller islands during the afternoons will impact portions of the US Virgin Islands and eastern Puerto Rico each day.

Some of the expected risks throughout the long-term include ponding of water in roads and poorly drained areas as well as a a low chance of urban and small streams flooding over region where frequent downpours occur. One of the main concerns for the long-term forecast are associated to heat. The available moisture, calm winds, and lower cloud cover and above seasonal 925 mb temperatures will lead to a level of heat that affects most individuals sensitive to heat, especially those without effective cooling and/or adequate hydration.

AVIATION

(06Z TAFS) Issued at 306 AM AST Wed Nov 11 2026

Mainly VFR conditions are expected to prevail across all TAF sites during the forecast period. However, locally induced -SHRA/-TSRA may develop in and around TJSJ/TJBQ between 11/17-21z. This can result in intermittent/brief MVFR conds. E-SE winds up to 10 kt with sea breeze variations expected aft 11/13z, then becoming lgt/vrb aft 11/22Z.

MARINE

Issued at 306 AM AST Wed Nov 11 2026

A northerly swell will continue to subside today. Meanwhile, building surface high pressure across the central Atlantic will tighten the local pressure gradient, resulting in increasing east to southeast trade winds. Moderate to fresh trades will develop Thursday and persist through Saturday, producing increasingly choppy to confused seas. Small craft should exercise caution across portions of the local waters during this period. Afternoon thunderstorms developing over Puerto Rico may move over the adjacent coastal waters and produce locally hazardous marine conditions, including higher winds and seas.

BEACH FORECAST

Issued at 306 AM AST Wed Nov 11 2026

A moderate risk of life-threatening rip currents will prevail today along most northern and eastern beaches of Puerto Rico, Culebra, Vieques, and the U.S. Virgin Islands. The moderate risk will remain widespread through Saturday, expanding at times to portions of the southern and western beaches of Puerto Rico as the trade winds strengthen.

Some improvement is expected Sunday, particularly along the northern and eastern beaches, although a moderate risk will continue along portions of the southern coast. By Monday, the moderate risk may return to portions of the northern and western beaches of Puerto Rico.

With increased beach activity expected for Veterans Day, beachgoers should remain cautious, as life-threatening rip currents are possible in the surf zone.

SJU WATCHES/WARNINGS/ADVISORIES

PR...High Rip Current Risk until 6 AM AST early this morning for PRZ001-002-005-008-010-012.

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