Marine Weather and Tide Forecast for Pole Ojea, PR

SHORT TERM
Tonight through Wednesday...

A surface high-pressure system over the central Atlantic will maintain a tight pressure gradient across the region, resulting in breezy conditions with steering flows around 15-20 knots. Weather stations across the islands have already reported wind gusts ranging from the mid-20s to low 30s (mph), reflecting the influence of this pattern.

The weather pattern remains generally on track, with some changes expected through most of the short-term forecast period. The TJSJ 12/12Z upper-air sounding indicated a slight reduction in moisture content, with precipitable water at 1.49 inches and mid-level relative humidity at 45%. Wind direction has also shifted slightly, with winds from the east-northeast at 14 to 15 knots at the surface to 2 km and 3 km layers. Radar and satellite data support this trend, showing streamers developing downwind of the smaller islands and extending from northeast to southwest. GOES-19 precipitable water imagery further confirms the drying trend, depicting an airmass between 1.4 and 1.5 inches moving in from the east.

A ridge building at the mid to upper levels is settling in and will persist through the short-term forecast period, contributing to a more stable weather pattern characterized by warming 500 mb temperatures and decreasing lapse rates. Moisture content is expected to decrease further on Tuesday before increasing to near or above normal levels from Wednesday into Wednesday night, as winds shift from the southeast and pull plenty of tropical moisture across the CWA Despite the more stable conditions aloft, sufficient low- level moisture will remain to support shallow convection each afternoon, enhanced by diurnal heating and local effects. The highest flooding risk will be over southwestern Puerto Rico this afternoon and tomorrow, with Tuesday expected to see the least shower coverage. On Wednesday, despite the presence of ridging aloft, the surge in moisture will lead to increased shower activity, particularly along windward coastal areas during the evening hours, and across interior and western to northwestern Puerto Rico under the influence of the southeasterly wind flow.

LONG TERM
Thursday through Monday...

PREV DISCUSSION
/issued 527 AM AST Mon May 12 2025/

Increasingly wet and unstable condtions are forecast during most of the long term forecast period. After mid-week, current model guidance has precipitable water (PWAT) values close to around 2 inches, above normal values for this time of the week. A decrease in PWAT values is forecast by late Sunday and Monday, decreasing to around 1.8 inches. A mid to upper-level ridge present on Thursday will gradually weaken as a mid to upper level trough moves eastward from the western Atlantic towards the local islands, this will promote more favorable conditions for shower and thunderstorm development late Thursday onwards. A surface trough will also develop, also providing instability and promoting, along with a surface high over the central Atlantic, more east-southeast to southeast steering flow over the region.
Deep tropical moisture will start to move into the region, with current model guidance showing a completely moist atmospheric profile, possibly being somewhat confined once again to below 650mb by late Saturday and into early next week. With the prevailing wind flow, increased temperatures are also forecast in areas without significant cloudiness, particularly during the late morning hours. Ultimately this diurnal heating, along with sea breeze convergence and local orographic effects, can also help promote shower and thunderstorm development, adding to the already unstable atmospheric conditions. By Friday and into the weekend, conditions will be conducive to increased convective activity.
Widespread showers and thunderstorms are forecast, particularly across the Cordillera Central and western Puerto Rico, with lines of convection possibly also developing from the local islands and El Yunque. With already saturated soils and these moist and unstable conditions, a limited to elevated flooding risk is forecast during these days, meaning that urban, small stream and flash flooding is possible. Stay tuned for any updates.

AVIATION
(18Z TAFs)

Mainly VFR conditions across most TAF sites. VCSH across TJSJ, TJPS over the next hours, then tonight across TISX. Main concern will continue to be the easterly breezy winds, expected around 10 to 15 knots with gusts up to 27 to 30 knots at least through 12/23Z, decrease to 8 to 12 knots overnight and then increase again tomorrow by 12 to 14Z.



MARINE

A broad surface high pressure system over the central Atlantic will sink southward over the next few days, leading to increasing winds and choppy conditions across the offshore waters. A Small Craft Advisory is now in effect for the Atlantic offshore waters and the Anegada Passage, with seas expected to build up to 7 feet by this afternoon. Small craft should exercise caution across most of the other local waters. Thunderstorm activity is likely across regional waters, particularly during the afternoon and evening hours, which may result in locally higher winds and seas.

BEACH FORECAST

Tonight, there is a moderate risk of rip currents across all coastal areas of Puerto Rico, Vieques, Culebra, and the U.S. Virgin Islands.
This moderate risk will persist through most of the workweek in these same areas, except along the western and central southern coasts of Puerto Rico, where a low risk is more likely. Life- threatening rip currents often occur near jetties, reefs, and piers.
A low risk is anticipated by the end of the week and into the weekend.

HYDROLOGY

Forecast models continue to indicate the development of another wet and unstable weather period in recent updates. By the end of the workweek, increasing atmospheric instability, combined with abundant tropical moisture, is expected to result in widespread thunderstorm activity, with some storms capable of producing heavy rainfall. This pattern will be driven by the interaction between a deep-layered trough and unusually high precipitable water values for this time of year, ranging from approximately 2.0 to 2.25 inches. The wet and unstable weather pattern is expected to persist through the weekend.

Prolonged periods of moderate to heavy rainfall will increase the risk of urban and small stream flooding, flash flooding, and mudslides in areas of steep terrain. Additionally, significant runoff from excessive rainfall could result in quick river rises, with some rivers potentially exceeding flood-stage levels. Soils remain saturated and streamflows elevated due to the extended wet period experienced in recent weeks. These antecedent conditions will further exacerbate the aforementioned impacts across the region.
Residents and visitors, especially those in flood-prone areas or planning outdoor activities, are advised to closely monitor the latest weather forecasts and updates.

SJU WATCHES/WARNINGS/ADVISORIES
PR...None.
VI...None.
AM...Small Craft Advisory until 6 AM AST Tuesday for AMZ711-723.