textproduct: San Juan

KEY MESSAGES

Updated at 416 AM AST Tue Apr 7 2026

* Flooding risk increases this week, highest through midweek. Periods of showers and thunderstorms each afternoon and evening will increase the risk of urban and small-stream flooding, with isolated flash flooding possible across Puerto Rico.

* Dangerous rip currents expected through at least Wednesday, increasing late week. Breezy conditions and choppy seas will create life- threatening rip currents across most beaches. From Thursday onward, northern and eastern beaches of Puerto Rico and the U.S. Virgin Islands will see a higher risk due to incoming northerly swell.

* Hazardous marine conditions for small craft continue. A Small Craft Advisory remains in effect for Atlantic offshore waters and the Anegada Passage through at least this afternoon. Elsewhere, small craft should exercise caution.

* Breezy to locally windy conditions persist through Saturday. Winds will enhance shower activity and contribute to hazardous marine and coastal conditions.

* Above-normal heat indices return through Sunday. Elevated heat index values will increase the risk of heat-related impacts, especially for individuals outdoors without adequate hydration or cooling.

Short Term(Today through Thursday)

Issued at 416 AM AST Tue Apr 7 2026

Under a southeast wind flow, showers moved inland across the windward areas of south and east PR, Vieques, Culebra, and the US Virgin Islands, producing ponding in poorly drained areas. However, heavy rain impacted the eastern municipalities, especially the Naguabo region along the Rio Blanco, causing flooding at the Intersection of PR-191 and PR-31, near the highway exit, where emergency managers closed the road due to impassibility. Rain activity moved further inland across portions of the southern interior near Adjuntas and northeastern PR early this morning. St Croix also observed descent periods of moderate to locally heavy rain during this activity, resulting in ponding in poorly drained areas. Low temperatures ranged from the mid- to low-70s along the coast to the mid- to upper-60s in the mountains.

Under southeast wind flow and above-normal moisture content, which will last through the next few days, we expect the continuation of the wet, unstable weather pattern across PR and the USVI. Model guidance still suggests a steep lapse rate from 850 to 500 mb, as well as plenty of atmospheric moisture, which, combined with the excessive heating that 925 mb temperatures are suggesting, we can expect another round of strong afternoon convection today and each day during the short-term period. Under this weather pattern, we have forecast a limited to elevated risk of flooding for portions of the islands during this period. Additionally, the 925 mb winds are near or above normal, which will continue to pool plenty of moisture over the region, enhancing the showery weather from time to time. Another threat associated with this pattern is lightning and thunderstorm winds.

Tuesday and Wednesday seem the wettest and most unstable days of the forecast, becoming less active (at least according to model guidance) on Thursday. However, we cannot rule out strong thunderstorms, enhanced by the increasing warming period during the afternoon across portions of the region. Although we expect periods with little or no rain, rounds of moderate to locally heavy rain will impact portions of the islands each day, especially across the USVI and PR's windward locations overnight and in the morning, and across the western and northern portions of PR in the afternoon.

According to the weather pattern described, the threats for Tuesday and Thursday include: a warm to locally hot heat index in the afternoons, a limited to elevated risk of flooding rain in parts of Puerto Rico and the U.S. Virgin Islands, breezy to locally windy conditions, a moderate to high risk of life- threatening rip currents, and dangerous lightning associated with thunderstorms. Please take appropriate precautions during this time.

Long Term(Friday through Tuesday)

Issued at 416 AM AST Tue Apr 7 2026

Conditions will become relatively stable through the long term period. Expect isolated to scattered showers, mainly during the afternoon hours due to daytime heating. Activity will be focused across western and interior Puerto Rico, with minimal impacts elsewhere. Overall rainfall coverage and intensity should be lower than previous days. Winds will remain from the east-southeast, continuing to bring typical pockets of moisture into the region, from time to time. Model guidance continues to suggests the gradual return to a wetter and more unstable pattern. An approaching deep- layered trough combined with above-normal moisture could lead to increasing shower and thunderstorm activity across the region, particularly from Monday onwards.

AVIATION

(06Z TAFS) Issued at 416 AM AST Tue Apr 7 2026

VFR conds are expected at local terminals, but MVFR and brief IFR may occur due to passing rain SHRA/TSRA. Eastern/southern terminals like TIST/TISX/TJSJ/TJPS will experience SHRA embedded in the wind flow, especially in the morning and evening. Afternoon convection will mainly affect western/northern terminals, such as TJBQ/JSJ. Winds will be from the SE at 5 to 15 kt thru 7/13Z, then at 10 to 20 knots, with higher gusts near convection and sea breeze. Expect mnt obsc, reduced visibility in +SHRA/TSRA.

MARINE

Issued at 416 AM AST Tue Apr 7 2026

Hazardous marine conditions will persist through at least late this afternoon as a strong high-pressure system over the Atlantic maintains moderate to fresh southeasterly winds. Therefore, expect confused seas, particularly across Atlantic waters and local passages through at least this evening. Conditions are expected to gradually improve tonight, with seas subsiding to around 5 feet in the Atlantic and up to 4 feet in the Caribbean. While trade wind showers continue to move across the region, isolated to scattered thunderstorms are likely each afternoon, especially over coastal waters near western, northern, and northwestern Puerto Rico. Shower and thunderstorm coverage may increase later this week due to a series of troughs approaching the region.

BEACH FORECAST

Issued at 416 AM AST Tue Apr 7 2026

Although moderate rip current risk will persist for the northern exposed beaches, life-threatening rip currents are still possible. Conditions should deteriorate by the end of the week due to a series of swells arriving and spreading across local Atlantic waters and passages. Residents and visitors are encouraged to check the latest beach conditions before heading to the beach at weather.gov/sju and https://www.weather.gov/beach/forecast?site=sju&action=.

In addition to the life-threatening rip currents, beachgoers visiting beaches over western and northwestern Puerto Rico in the afternoons should remain weather alert due to the development of isolated thunderstorms. Hazards include gusty winds, reduced visibility due to heavy rainfall, and lightning. Seek shelter inside a building whenever you hear lightning.

SJU WATCHES/WARNINGS/ADVISORIES

PR...None. VI...None. AM...Small Craft Advisory until 6 PM AST this evening for AMZ711-723.