Southern US Virgin Islands, Vieques and Eastern Puerto Rico out 10nm Marine Forecast
| Rest Of Today...Southwest Winds 5 To 10 Knots. Seas 1 To 3 Feet. Dominant Period 11 Seconds. Isolated Showers. |
| Tonight...West Winds 5 To 10 Knots. Seas 1 To 3 Feet. Dominant Period 10 Seconds. Isolated Showers. |
| Thursday...West Winds 5 To 10 Knots. Seas 2 To 4 Feet With Occasional Seas Around 5 Feet. Dominant Period 10 Seconds. Numerous Showers. |
| Thursday Night...North Winds 10 To 15 Knots. Seas 4 To 6 Feet With Occasional Seas Up To 8 Feet. Dominant Period 11 Seconds. Scattered Showers. |
| Friday...North 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 3 To 5 Feet With Occasional Seas Up To 6 Feet. Dominant Period 12 Seconds. Isolated Showers. |
| Sunday...South 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 406am AST Fri April 19 2024 Synopsis The risk of flooding will remain elevated today, especially for the municipalities along the interior. Another active afternoon is expected under a light wind flow. Soils are saturated and rivers are running high, so even little precipitation may result in flooding and mudslides. This afternoon activity will continue for the next few days. Some Saharan dust could reach the islands early in the next workweek, and temperatures are expected to warm up too. .SHORT TERM...Today through Sunday... Showers lingered across the interior sections of Puerto Rico during the evening hours however cleared before midnight when an increase of passing showers over northern Puerto Rico and the USVI were seen. Winds lightened and became variable with speeds around 3 mph this morning. Heavy rainfall yesterday caused Rio Grande de Manati and Rio La Plata to overflow their banks, causing flooding on the roads they intersect. Due to this, flood warnings were issued until the morning. A light lower level steering flow is hinting at another afternoon of active weather for the interior to southern sections of Puerto Rico. Meanwhile, passing showers across windward sections will continue. During the afternoon, convection will likely begin across southwestern PR, then spreading eastward along the Cordillera Central. Thunderstorms are possible and will be capable of producing lightning and strong wind gusts. Heavy rainfall is very likely with a few inches of accumulation possible across sections that are already saturated due to previous days of rainfall. Due to this, there is an elevated to significant risk of flooding for the central interior sections of Puerto Rico today. Take caution and watch for rapid river rising, mudslides, and flooded streets. Showers are expected to linger through the early evening hours. However, the arrival of drier air will limit the amount of rain seem through the night. Passing showers remain possible. As an area of high pressure at the surface located in the western Atlantic continues to build, light to moderate NE winds will continue. This will concentrate Saturday's afternoon convection across the southwestern sections of Puerto Rico. However, due to the arrival of drier air, less rain is forecast compared to the previous days. A similar pattern is expected on Sunday as the aforementioned surface high moves north of the region causing veering in the surface winds to an easterly direction, which will bring the best chance of rain across the interior to western sections of Puerto Rico. Long Term Monday through Friday... The next workweek will begin with a 60% chance of experiencing above normal precipitation across the local islands. First of all, a high pressure system northeast of the islands will maintain the winds from the southeast at around 8 knots. A straight line of moisture stretching from a low pressure system just east of the high pressure will keep a dense Saharan-Air-Layer just south of the local islands on Monday. However, small concentrations of these particulates could reach the islands, so skies may look hazy at times. With moisture lingering around, showers and isolated thunderstorms are anticipated to develop along the Cordillera Central in the afternoon. The winds from 850 to 700 mb are expected to be from the south, so this convection will move northward, possible reaching portions of the San Juan metro area. Then, another low pressure system is expected to exit the eastern coast of the United States, and the surface high will migrate northward. The line of moisture will continue to meander around the northeastern Caribbean, providing enough moisture to fuel afternoon convection through Thursday. On Friday, additional induced patches of moisture will be dragged across the region, but more breaks of sunshine are expected. Even with the afternoon rains, enough heating is expected late in the morning, and with a southerly flow, temperatures will be on the hot side, with highs reaching the upper 80s and low 90s, and heat indices above the 100 degree mark. Marine A set of surface troughs, one to the northwest and other to the northeast of the islands will promote light to locally moderate northeast winds today. A small northeasterly swell will move across the Atlantic waters through the weekend. The surface trough northeast of the region and a surface high pressure building across the western Atlantic will promote moderate trades by the weekend. Beach Forecast A small northeasterly swell will continue to move across the local islands, maintaining the risk of rip currents moderate for northern Puerto Rico, Culebra and eastern St. Croix. Hydrology Another round of strong showers and thunderstorms is expected for today under a very light wind flow. Due to previous rainfalls, soils are saturated and rivers are running high in the interior of Puerto Rico. Therefore, the risk for flooding and mudslides will be elevated again today. Additionally, it is likely that afternoon activity will not only focus on the main island of Puerto Rico, but Vieques, Culebra and the Virgin Islands could see convection popping up as well. .SJU WATCHES/WARNINGS/ADVISORIES... PR...None. VI...None. AM...None. |
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