textproduct: San Juan

KEY MESSAGES

Updated at 225 PM AST Fri Apr 24 2026

* The arrival of northeasterly swell pulses will keep the risk of life-threatening rip currents moderate to high along these beaches from the weekend into early next week.

* Afternoon convection will maintain a limited flooding risk each day across Puerto Rico, with the risk becoming elevated from Sunday into early next week.

* The PR and USVI regions are expected to experience warmer- than-normal temperatures starting around Sunday, with heat indices reaching or exceeding 100F.

Short Term(This evening through Sunday)

Issued at 225 PM AST Fri Apr 24 2026

In general, the US Virgin Islands and Puerto Rico observed little or no rain, with mostly clear skies this morning. However, by noon, showers affected St Croix and eastern PR, where periods of moderate to locally heavy rain formed. Maximum temperatures ranged from the mid-80s to the low-90s at coastal sites and from the upper-70s to mid-80s at mountain sites. The winds calm to light and variable under the influence of sea breeze variations.

This afternoon, under a southerly wind flow, showers will continue to move across St Croix and the southern sections of PR at times. Additionally, we cannot rule out showers developing across the mountains and surrounding slopes, where a limited risk of flooding rains remains. Across the northern U.S. Virgin Islands, generally calm conditions are expected, with some showers brushing the islands or forming downwind of them. We cannot rule out showers tonight and overnight as the southerly winds advect additional moisture to the southern and eastern portions of PR and the USVI.

Model guidance shows instability increasing as a mid to upper- level trough moved over the region from the west. However, available moisture is near or below normal on Saturday, but it might increase by Sunday, as model guidance now indicates. The weak steering wind flow will maintain a limited risk of flooding on Saturday. Under the aforementioned weather pattern, the best chance of strong thunderstorms is on Sunday as moisture and instability increase, when the flooding rain risk is elevated. Still, the limiting factor observed includes a somewhat drier air mass at mid levels, which could inhibit widespread activity, even though available moisture will increase at lower levels.

The southeasterly flow will bring warmer-than-normal temperatures and increased heating on Sunday. This will lead to an active afternoon convection cycle, with showers developing in the interior and moving north, potentially resulting in isolated thunderstorms. Higher moisture levels and stronger heating will enhance rainfall efficiency, raising the chance of locally heavy rain and a slight risk of excessive rainfall.

Long Term(Monday through next Thursday)

Issued at 225 PM AST Fri Apr 24 2026

A strengthening high-pressure system over the central Atlantic will maintain a consistent south-southeasterly wind flow across the region. Simultaneously, a deepening upper-level trough will create unstable conditions aloft. This pattern will bring abundant moisture from the Caribbean into the islands, significantly increasing the potential for showers and thunderstorms.

A gradual increase in moisture is expected from Monday through Wednesday, with precipitable water values reaching up to 2.25 inches; the bulk of this moisture is anticipated to arrive by Tuesday afternoon. Consequently, shower activity is anticipated during the morning hours across the U.S. Virgin Islands and eastern Puerto Rico. By the afternoon, the combination of daytime heating, local effects, and abundant moisture will likely trigger moderate to heavy rainfall across the interior and western portions of Puerto Rico. While temperatures at 500 mb will remain near seasonal averages (between -7 to -8C), there is sufficient atmospheric dynamics to support thunderstorm activity.

As winds prevail from the south-southeast, temperatures at the 925 mb level will rise well above climatological norms from Monday through the latter part of the week. Maximum surface temperatures are expected to range from the upper 80s to low 90s in coastal and urban areas, and the low to mid-80s in higher elevations. Due to high humidity values and southerly flow, heat indices will likely surpass 100F daily. Residents and visitors are strongly encouraged to prioritize hydration and limit prolonged sun exposure to stay safe during this period of excessive heat.

AVIATION

(18Z TAFS) Issued at 225 PM AST Fri Apr 24 2026

VFR are expctd to persist across TAF sites, with -SHRA/+SHRA bringing VCSH through 24/23z. -SHRA will continue for ISX, reducing CIGs/VIS, and may briefly bring MVFR conds. AMDs will be issued if required. Winds will once again weaken and become VRB over PR sites, while USVI sites will remain light from the SE around 10 kt. Winds will gradually increase btwn 5 - 12 kt by 25/12-14z.

MARINE

Issued at 225 PM AST Fri Apr 24 2026

A weak frontal boundary meandering just north of the region will continue to weaken and transition into a trough as it lingers near the northeast Caribbean region and lifts north of it. At the same time, a surface high over the southwestern Atlantic shifts east into the central Atlantic. This pattern will maintain light east- southeast to southeast winds today, followed by a brief increase and a veering to a more southerly flow into early Saturday before easing again through the weekend. Pulses of northeasterly swell will move across the Atlantic Waters and Caribbean Passages during the weekend and early next week.

BEACH FORECAST

Issued at 225 PM AST Fri Apr 24 2026

Beachgoers, there is a moderate risk of life-threatening rip currents along the north-facing beaches from Rincon to Fajardo, as well as on the northern beaches in Culebra, Vieques, St. Croix, St. Thomas, St. John, and adjacent islands. These conditions will last through much of the forecast. However, the arrival of occasional pulses of northeasterly swell will promote a moderate/high chance of rip currents along these locations. We encourage active monitoring of beach conditions for additional updates.

The risk of rip currents will be low in the south-facing beaches of Puerto Rico and the U.S. Virgin Islands.

In addition, beachgoers should remain alert for afternoon thunderstorms, particularly across western Puerto Rico. These storms may produce gusty winds and frequent lightning.

SJU WATCHES/WARNINGS/ADVISORIES

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