Isabela, Puerto Rico Weather

Key Messages

Issued at 145 AM AST Tue Oct 20 2026

* Dangerous surf, hazardous seas, and life-threatening rip currents will affect the Atlantic waters, exposed passages, and north-facing beaches of Puerto Rico, Culebra, and the northern U.S. Virgin Islands through Wednesday, with conditions gradually improving thereafter.

* Afternoon thunderstorms may produce lightning, locally heavy rainfall, and urban or small-stream flooding across northern Puerto Rico today. Activity should decrease Wednesday before a surge of tropical moisture brings more widespread showers and renewed flooding concerns Thursday into the weekend.

* Wednesday will likely be the warmest day of the period, with heat primarily affecting individuals extremely sensitive to heat, especially those outdoors without effective cooling or adequate hydration.

Aviation

(06Z TAFS) Issued at 145 AM AST Tue Oct 20 2026

Passing SHRA may produce brief MVFR cigs/vsbys across USVI terminals and TJSJ through 20/13-14Z. Aftn SHRA/TSRA may bring MVFR/IFR conds to TJSJ after 20/15-16Z and TJBQ after 20/16-17Z, mainly due to reduced vsbys in heavier SHRA/TSRA and locally low cigs. VCTS also possible near TJPS and USVI terminals, with activity diminishing after 20/22Z. Sfc winds light/VRB overnight, becoming ESE-SE at 5-10 kt after 20/13Z, with sea breeze variations and locally gusty winds near TSRA.

Marine

Issued at 145 AM AST Tue Oct 20 2026

A weak pressure gradient between a frontal boundary over the western Atlantic and high pressure to the east will maintain gentle to moderate east to southeast winds through midweek. Despite the relatively light winds, a significant long-period north-northwesterly swell is expected to peak today before becoming more northerly Wednesday. Seas near 6 feet across the Atlantic waters and exposed passages will warrant caution for small craft operators, with conditions gradually improving as the swell subsides. Meanwhile, increasing tropical moisture Thursday into the weekend may favor more widespread showers and thunderstorms, potentially bringing lightning, locally gusty winds, and reduced visibility over the waters.

Beach Forecast

Issued at 145 AM AST Tue Oct 20 2026

A significant long-period north-northwesterly swell is expected to peak today, with breaking waves of 8 to 12 feet possible along exposed northern and northwestern beaches of Puerto Rico, from Rincon to Fajardo. A High Surf Advisory remains in effect through 6 PM AST this evening, with dangerous swimming conditions and possible localized beach and dune erosion. High tide around 3 to 4 PM AST, reaching approximately 1.5 feet along northern Puerto Rico, Vieques, and Culebra, may enhance wave runup and localized beach erosion along exposed shorelines. Large waves may also wash over exposed rocks and jetties.

A High Rip Current Risk will continue through Wednesday afternoon along these beaches and the north-facing beaches of Culebra. The risk is also expected to increase to high along the north-facing beaches of St. Thomas, St. John, and adjacent islands beginning this evening through Wednesday afternoon. Although surf heights should gradually decrease Wednesday as the swell becomes more northerly and subsides, life-threatening rip currents will remain a concern.

Beachgoers should remain out of the water at affected beaches and away from exposed rocks and jetties. Improving surf conditions later in the week may be accompanied by increasing showers and thunderstorms, potentially bringing lightning and gusty winds to coastal areas. Seek shelter in a substantial building or enclosed vehicle when thunder is heard. For additional information, refer to the latest Coastal Hazard Message (CFWSJU).