textproduct: San Juan

KEY MESSAGES

Updated at 115 PM AST Thu May 7 2026

* Warm to hot weather will continue through the middle of next week, particularly in urban and coastal areas of Puerto Rico and the U.S. Virgin Islands.

* Heat indices exceeding 100F are expected each afternoon. Scattered afternoon showers are expected across western Puerto Rico, with the potential for locally heavy rainfall and isolated thunderstorms.

* A typical early May weather pattern is expected through at least the middle of next week, with mainly clear mornings followed by afternoon showers over western and interior Puerto Rico each day.

* Moderate rip current risk will continue for north- and east- facing beaches of Puerto Rico, Culebra, Vieques, and the U.S. Virgin Islands for much of the forecast period.

Short Term(This evening through Saturday)

Issued at 115 PM AST Thu May 7 2026

In general, the US Virgin Islands and Puerto Rico had mostly clear skies and above-normal temperatures, with maximum temperatures reaching the low and mid-90s at coastal sites (especially across western PR and the US Virgin Islands) and heat indices up to 107 degrees Fahrenheit. Some showers moved across St Croix, St Thomas, and St John early in the morning, and some were detected downwind from the islands in the form of streamers early this afternoon. Eastern PR also observed showers, especially in Yabucoa, where radar estimated up to 1.8 inches. Cloudiness is also increasing across most of PR and downwind from the USVI at the moment of writing this discussion. The winds were mainly from the east-southeast at 5 to 17 mph, influenced by sea breeze variations.

A surge of moisture will combine with the excessive heating, local effects, and sea breeze variations, resulting in showers and isolated thunderstorms across the interior and west sections of PR. This activity will continue into the evening across these regions. After this activity dissipates, conditions will become calm, with mostly clear skies. The eastern sections of PR and the USVI will observe calm weather this afternoon and evening, though showers may occasionally arrive. The islands, especially urban and coastal areas, will experience warmer-than-normal temperatures and higher heat indices.

The upper-level trough will continue to pull away from the Lesser Antilles into the Atlantic Ocean through Saturday, as a mid- to upper-level ridge and associated dry air aloft will maintain subsidence across the northeastern Caribbean, limiting the potential for widespread flooding. Nevertheless, the advection of moisture pockets will bring occasional showers to the USVI and the windward sections of PR, followed by afternoon convection driven by local effects, sea breeze convergence, and daytime heating each day, mainly across the interior and western sections of Puerto Rico. Some of this activity may produce periods of moderate to locally heavy rainfall, especially in the afternoon.

Also, the region will likely experience a warming trend, as model guidance indicates above-normal temperatures at 925 mb.

Long Term(Sunday through next Wednesday)

Issued at 115 PM AST Thu May 7 2026

A predominantly stable weather pattern will prevail through midweek as a mid-level ridge remains anchored over the northeastern Caribbean. This will continue to promote subsidence and maintain a drier-than-normal environment, with available moisture largely confined below 700 mb. As a result, vertical development will be limited, favoring mostly fair weather conditions across the region. Model guidance remains in good agreement, showing little deviation from this pattern through the period.

At the surface, an east to east-southeasterly flow will dominate, supporting a typical trade wind pattern. Brief, fast-moving showers will affect windward areas during the overnight and early morning hours, followed by isolated to locally scattered afternoon convection over interior to western Puerto Rico, driven by local effects and possibly enhanced by intense diurnal heating. However, overall rainfall coverage will remain limited, and thunderstorm development is expected to be minimal.

The main hazards during this period will be heat and breezy conditions. Above-normal temperatures combined with warm low-level moisture will promote a limited heat risk each day, particularly for sensitive individuals or those engaging in prolonged outdoor activities without adequate hydration. In addition, breezy conditions will persist, especially across exposed coastal and windward areas, leading to a limited non-thunderstorm wind risk with occasional gusts around or above 25 mph. The combination of these factors may support an elevated fire danger risk, particularly across southern and coastal Puerto Rico where fuels will continue to dry.

AVIATION

(18Z TAFS) Issued at 115 PM AST Thu May 7 2026

VFR conditions across all terminals. Brief MVFR condt possible near the VCTS/TSRA over TJBQ and TJPS aftern 07/18Z. Winds will remain from SE around 9 - 19kts with occasional higher gusts around 23kt, becoming light and variable overnight. VCSH over TIST, TISX, and TJSJ after 07/09 - 07/12Z.

MARINE

Issued at 115 PM AST Thu May 7 2026

Expect a moderate east-to-southeasterly wind flow to prevail through this evening. Beginning tonight and continuing through Sunday, a strengthening surface high pressure over the western Atlantic will promote moderate to locally fresh east-to-northeast winds across the regional waters. Thus, expect choppy marine conditions due to the increasing winds. Breezy trade winds will persist into early next week, with winds occasionally reaching up to 20 knots; therefore, small craft should exercise caution across portions of the local waters.

BEACH FORECAST

Issued at 115 PM AST Thu May 7 2026

The risk of rip currents is low along the southerly facing beaches in PR and the USVI. However, we encourage beach enthusiasts to exercise caution while enjoying the north- and east-facing beaches from Rincon to Fajardo, as well as the northern shores of Culebra and Vieques.

As we move into the weekend and early next week, the increasing wind pattern will promote a moderate risk of rip currents across most of Puerto Rico, St. Croix, St. Thomas, St. John, and nearby islands, potentially forming life-threatening rip currents as they break at the shore. Stay safe!

Keep an eye out for possible afternoon thunderstorms across portions of western PR, which could bring strong, gusty winds and lightning.

SJU WATCHES/WARNINGS/ADVISORIES

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