textproduct: San Juan

KEY MESSAGES

Updated at 225 PM AST Fri May 8 2026

* Warmer-than-normal temperatures will persist, with heat indices reaching or exceeding the upper 90s to 100 degrees F, particularly in urban and coastal areas of PR and the USVI.

* Strengthening winds will promote a moderate risk of rip currents along the north and east-facing beaches of PR, Culebra, and the USVI through next week, along with choppy marine conditions across the local waters.

* Locally induced afternoon showers are expected to develop each day over portions of western PR.

* Across the USVI, mostly fair weather conditions will persist, however, passing trade wind showers may occur during the night and early morning hours.

Short Term(This evening through Sunday)

Issued at 225 PM AST Fri May 8 2026

As the upper-level trough exited the area and a drier-than-normal air mass settled in, mostly fair weather conditions prevailed across the forecast region this morning and early afternoon. The 12Z TJSJ sounding showed PWAT values around 1.30 inches, which is considered below normal for this time of year. Additionally, a limited heat threat remains across the urban and coastal areas of the islands. As observed at several surface weather stations, warm conditions have persisted, with heat indices reaching the upper 90s and even the lower 100s. Winds have been blowing mainly from the east to east-northeast at around 12 to 18 mph, with occasional higher gusts and typical sea breeze variations. This afternoon, expect some cloudiness developing and showers confined over the southwestern Puerto Rico, if any.

Over the short-term period, a mid-level ridge will remain the dominant feature, promoting mostly stable conditions across the region. The latest satellite-derived precipitable water values and model guidance indicate values around 1.5 inches or less, which is below normal for this time of year. At the surface, a high-pressure north of the region will promote breezy conditions over the weekend. This flow will steer occasional shallow moisture patches across the islands, bringing brief, fast-moving showers to windward sections of the USVI and eastern Puerto Rico during the overnight and early morning hours. Each afternoon, isolated to scattered showers are expected to develop over portions of western Puerto Rico through the weekend. The flood threat and lighting risk will remain minimal to very low.

Overall, fair weather conditions are expected, with localized afternoon showers over western Puerto Rico and the primary concern being the persistent heat risk. The 925 mb temperature guidance is suggesting values in the near normal to above normal through the weekend. Expect daytime highs in the mid to upper 80s degrees F in coastal and urban areas, with heat indices reaching or exceeding the upper 90s to 100 degrees F.

Long Term(Monday through Friday)

Issued at 339 AM AST Fri May 8 2026

A generally drier-than-normal pattern for shower development will persist through the period as mid-level ridging and subsidence dominate across the region. Moisture will remain below normal for this time of year and mostly confined below 700750 mb, limiting vertical growth and resulting in reduced shower activity. An east to east-southeasterly steering flow will prevail, supporting a consistent daily pattern with brief, quick-moving passing showers affecting windward areas during the overnight and morning hours, followed by isolated afternoon convection over interior to west- northwestern Puerto Rico, driven by local effects and mostly diurnal heating. Isolated thunderstorms cannot be ruled out, but coverage will remain very limited. Minor traces of Saharan dust may be present at times, though concentrations are expected to remain low.

Breezy conditions will increase into the weekend and early next week, particularly across coastal and windward areas, supporting a limited non-thunderstorm wind risk with occasional gusts up to around 25 mph or higher at times. Increasing temperatures combined with warm and humid low-level conditions will promote a limited heat risk each day, mainly affecting sensitive individuals or those with prolonged outdoor exposure and inadequate hydration. In addition, the combination of warm temperatures and increasing winds will maintain the potential for elevated fire danger, particularly across southern and coastal areas where fuels will continue to dry.

AVIATION

(18Z TAFS) Issued at 225 PM AST Fri May 8 2026

VFR conditions are expected across all TAF terminals. Winds will remain from E-ENE around 12 to 18 kts with occasional higher gusts around 15 to 20 kts, becoming light and variable overnight. VCSH over TIST and TISX are possible during the overnight period. From 09/14Z, winds are expected to increase again and some VCSH are possible across TJBQ.

MARINE

Issued at 225 PM AST Fri May 8 2026

A strengthening surface high pressure over the western Atlantic will promote moderate to locally fresh east-to-northeast winds across the regional waters. As a result, choppy marine conditions are expected due to increasing winds over the weekend. Breezy trade winds will persist into early next week, with sustained winds of 15 to 20 knots and occasional higher gusts. Seas will range between 3 and 5 feet, occasionally reaching up to 6 feet. Small craft operators should exercise caution across portions of the local waters.

BEACH FORECAST

Issued at 225 PM AST Fri May 8 2026

This afternoon and tonight, a low risk of rip currents will persist across all beaches of Puerto Rico and the U.S. Virgin Islands. However, life-threatening rip currents can still occur near groins, jetties, reefs, and piers. Over the weekend, increasing winds will promote a moderate risk of rip currents across north and east-facing beaches of Puerto Rico and the U.S. Virgin Islands, resulting in life-threatening rip currents as waves break at the shore. For additional information and location- specific rip current details, visit weather.gov/beach/sju.

FIRE WEATHER

Issued at 225 PM AST Fri May 8 2026

No rainfall have been seen across the southern sections of Puerto Rico so far today and drier air mass over the region is allowing relative humidity values to drop into critical fire weather thresholds. The Cabo Rojo and Camp Santiago RAWS stations have been registering RH values in the upper 40s to low 50s and winds speeds in around 10 to 13 mph, with gust around 20 to 23 mph. Therefore, at this time conditions remain favorable for the spread of wildfires along the southern coastal plains of Puerto Rico. Some relief is expected this afternoon as some showers should develop across southwestern Puerto Rico. Fire partners are encouraged to remain vigilant as similar conditions are likely to prevail over the coming days.

SJU WATCHES/WARNINGS/ADVISORIES

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