Puerto Rico Caribbean Waters from 10nm to 17N Marine Forecast
| Rest Of Today...South Winds 5 To 10 Knots. Seas Around 2 Feet Or Less. Dominant Period 11 Seconds. Isolated Showers. |
| Tonight...West Winds 5 To 10 Knots, Becoming Northwest After Midnight. Seas Around 2 Feet Or Less. Dominant Period 11 Seconds. Isolated Showers. |
| Thursday...West Winds 5 To 10 Knots. Seas 1 To 3 Feet. Dominant Period 11 Seconds. Isolated Showers. |
| Thursday Night...North Winds 10 To 15 Knots. Gusts Up To 25 Knots In The Evening. Seas 3 To 5 Feet With Occasional Seas Up To 6 Feet. Dominant Period 11 Seconds. Scattered Showers. |
| Friday...Northeast Winds 10 To 15 Knots With Gusts Up To 25 Knots. Seas 3 To 5 Feet With Occasional Seas Up To 6 Feet. Dominant Period 11 Seconds. Isolated Showers. |
| Saturday...Southeast Winds 5 To 10 Knots. Seas 2 To 4 Feet With Occasional Seas Around 5 Feet. Dominant Period 12 Seconds. Isolated Showers. |
| Sunday...Southeast Winds 5 To 10 Knots, Becoming East. Seas 3 To 5 Feet With Occasional Seas Up To 6 Feet. Dominant Period 12 Seconds. |
| Area Forecast Discussion National Weather Service San Juan PR 204pm AST Sunday Jun 7 2026 .Short Term(This evening through Tuesday)... Issued at 204pm AST Sunday 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 (Saharan Air Layer) 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 336am AST Sunday 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 (County Warning Area) (PWATs (Precipitable Waters) 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 (Global Forecast System) and ECMWF (European Centre for Medium-Range Weather Forecasts) is tending to typical and near above-normal PWAT (Precipitable Water) 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. Marine Issued at 204pm AST Sunday 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 204pm AST Sunday 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 204pm AST Sunday 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 5pm AST this afternoon for PRZ001>003-005- 007-008-010>013. VI... Heat Advisory until 5pm AST this afternoon for VIZ001-002. AM...None. |
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