textproduct: San Juan

KEY MESSAGES

Issued at 204 PM AST Sun Jun 7 2026

* Hazy skies and warmer-than-normal temperatures will persist through at least Tuesday as Saharan dust remains over the region and east-southeast winds continue.

* Afternoon showers and isolated thunderstorms are possible today and around the middle of the week across interior, western, and northern Puerto Rico, with localized heavy rainfall capable of causing ponding of water on roads and isolated urban flooding.

* Heat indices may reach hazardous levels this week, especially in coastal and urban areas. Additional Heat Advisories may be needed over the coming days.

* Passing showers will continue to affect windward areas of Puerto Rico and the U.S. Virgin Islands, particularly during the overnight and morning hours as patches of moisture move in with the trade winds.

* A moderate risk of life-threatening rip currents will continue through Monday on many exposed beaches due to breezy east- southeast winds. Conditions gradually improve Tuesday through Thursday, but beachgoers should still exercise caution near the surf zone.

Short Term(This evening through Tuesday)

Issued at 204 PM AST Sun Jun 7 2026

A weak tropical wave moved across the region this morning, leaving clouds and showers mainly across St Thomas, St John, St Croix, and the eastern and southern portions of PR. The most intense activity was observed along the southern coast of PR, but by mid-morning, most of it had dissipated or spread into the interior and northern PR. Surface winds were from the east- southeast at 10 to 20 mph, with higher gusts and sea breeze variations. Maximum temperatures were in the mid- to upper 80s, with some coastal and urban areas reaching the low 90s.

Afternoon convection will form across the interior, northern, and western PR, meanwhile, the USVI will have hazy skies due to the arrival of a drier air mass with Sahara Dust Particles. By the evening, most of PR will also observe hazy skies as the SAL layer covers the region. We cannot rule out a few thunderstorms across the portions of PR already mentioned; however, the dry air mass filtering over the region will limit the potential for just isolated amounts. Therefore, there is still potential for heavy rainfall, leading to roadway ponding or even urban flooding. Most of the region will experience hazy, partly to variably cloudy skies and warmer-than-normal temperatures.

Traces of dust particles will remain suspended in the atmosphere over the region through at least Tuesday, leading to hazy skies. This week will experience an east-to-east-southeast wind flow, contributing to warmer-than-normal temperatures. As a result, there is a possibility of additional Heat Advisories being issued in the coming days. Conversely, patches of clouds and moisture embedded in the winds may bring a few passing showers to the windward areas of the US Virgin Islands and Puerto Rico. Additionally, local effects, sea breezes, and daytime heating are likely to cause afternoon convection in the interior and western sections each day.

Long Term(Wednesday through Sunday)

Issued at 336 AM AST Sun Jun 7 2026

he long-term forecast remains on track, with Thursday being the wettest day of the period. A surface high pressure across the central Atlantic will weaken due to its interaction with a low pressure in the northern Atlantic, weakening the local pressure gradient and low-level winds. However, local pressure gradient is likely as another surface high builds in the Western Atlantic by Friday, with winds strengthening and resulting in breezy to locally windy conditions. A drier airmass, along with some patches of moisture, should move on Wednesday, with below into near climatological normal moisture content across the CWA (PWATs between 1.4 and 1.6 inches), with limited shower activity. However, the latest model solutions continue to suggest an increase in moisture content on Thursday, as a tropical wave approaches the Caribbean Basin and an upper-level trough deepens into the tropics. Although the latest deterministic guidance of the GFS and ECMWF is tending to typical and near above-normal PWAT values (1.6 - 1.8 inches), ensemble members suggest a clear increase in moisture content on both low and mid levels (between 70 and 80%). Additionally, the proximity of the trough should cool mid-level temperatures (500 mb temperature dropping between -7 and -8 degrees Celsius), allow cloud growth and ventilation, which supports deep convection activity. Hence, the most likely scenario for Thursday is for isolated to scattered showers moving over windward sections of the islands throughout the day, while afternoon convection should concentrate over interior and northwestern Puerto Rico. Additionally, local island streamers may develop, including the San Juan streamer. Rainfall accumulations across the aforementioned areas may lead to ponding of water over roadways and poorly drained areas, along with urban and small stream flooding. In addition to flooding, other hazards that can be expected are gusty winds and lightning. Although the tropical wave should remain south of the CWA and move westward across the Caribbean Basin, lingering moisture and "troughiness" associated with the trough could enhance shower and thunderstorm activity on Friday afternoon, though the flooding chance should remain limited over northwestern portions of Puerto Rico. By Saturday, the CWA should be under the subsidence side of the trough, while a drier airmass filters into the region. Although daytime heating and local effects may induce afternoon convection, this should remain shallow and isolated.

As mentioned in the previous discussion, guidance continues to suggest near above normal 925 mb temperatures under an east- southeast wind flow. With the available moisture, heat indices will likely exceed 100 degrees Fahrenheit across urban and coastal areas of the islands, particularly on Thursday and Friday. Therefore, the heat risk should increase to elevated levels, meaning that most individuals without adequate hydration and/or effective cooling, Heat Advisories cannot be ruled out.

AVIATION

(18Z TAFS) Issued at 204 PM AST Sun Jun 7 2026

Mainly VFR conditions, except -SHRA/-TSRA possible across TJBQ with brief MVFR conds thru 07/20-21Z. HZ will likely result in VIS reductions through the forecast period. E-ESE winds will continue around 10 to 16 kts with occasionally higher gusts, becoming lighter overnight, then increasing again aft 08/14Z.

MARINE

Issued at 204 PM AST Sun Jun 7 2026

The surface high-pressure system over the Atlantic Ocean will continue to promote moderate to locally fresh east-southeast winds and choppy seas across the offshore Atlantic waters and Caribbean Passages. Expect moderate east to east-southeast winds from Tuesday onward as the pressure gradient loosens over the Northeast Caribbean.

BEACH FORECAST

Issued at 204 PM AST Sun Jun 7 2026

There's still potential for life-threatening rip currents along the exposed beaches, mainly due to breezy to locally windy east- southeast winds through Monday. Therefore, beachgoers are urged to exercise caution, remain aware of surf conditions, and avoid venturing too far from shore, as life-threatening rip currents are possible across most of the region.

Between Tuesday and Thursday, the weakening winds will limit the risk of rip currents; however, please exercise caution on our local beaches.

FIRE WEATHER

Issued at 204 PM AST Sun Jun 7 2026

A weak tropical moved across the region this morning. Surface observations registered minimum RH values above fire critical fire thresholds. Winds from the southeast at 10 to 18 mph with occasionally higher gusts. Given the expected conditions the fire danger threat remains none to low the rest of the afternoon. Monitor the forecast the coming days as drier air accompanied with Saharan dust particles will continue to move into the region, allowing lower RH values through at least mid week.

SJU WATCHES/WARNINGS/ADVISORIES

PR...Heat Advisory until 5 PM AST this afternoon for PRZ001>003-005- 007-008-010>013.

VI...Heat Advisory until 5 PM AST this afternoon for VIZ001-002.

AM...None.