Marine Weather and Tide Forecast for Puerto Real, PR

SHORT TERM
Tonight through Wednesday...

Calm weather prevailed early in the morning across PR and the USVI. However, numerous showers and thunderstorms impacted the northern half of Puerto Rico late in the morning into the afternoon. Widespread strong showers and thunderstorms result in multiple regions with flooding problems late this morning into the afternoon. Currently, rainfall amounts ranged between 2 and 4 inches with isolated higher amounts. The maximum temperatures observed ranged in the upper 80s across lower elevations and the low 80s in the mountains. Today's winds were calm with the influence of the sea breeze but gusty near showers and thunderstorms.

For the rest of this afternoon, we anticipate another active day as the mid to upper trough lingered near the region, interacting with plenty of tropical moisture. The flooding threat continues to be elevated for most of PR, especially as soils are saturated and rivers run high. Thus, residents and visitors should stay updated on the weather and watch for official forecast updates because there is an ongoing flood risk. Additionally, the possibility of unexpected landslides along steep terrains is a significant concern.

Today's afternoon convection will slowly dissipate by this evening across most portions of the islands. However, the unstable and wet pattern will continue, and another round of showers will impact the northern portions of PR, enhanced by the land breeze.
Additionally, the eastern third of PR and the US Virgin Islands could expect another round with periods of moderate to heavy rain overnight and tomorrow morning. Soils are saturated, and river and stream flows are elevated. Therefore, any persistent moderate or heavy rain can lead to flooding issues, including minor flooding, flash flooding, river flooding, and landslides in steep terrain.

Furthermore, the wet and unstable weather pattern associated with the deep-layer trough and the weak steering wind flow at low levels (1-3 km) will enhance the duration of any downpour that could impact any particular region, aggravating the risk of flooding. Something to highlight is the somewhat drier air mass at mid-levels that model guidance suggests from Tuesday to Wednesday, which could indicate that the most robust convection activity could develop every afternoon due to sea breeze, local effects, and local diurnal heating.


LONG TERM
Thursday through Monday...
PREV DISCUSSION... /issued 509 AM AST Mon Apr 28 2025/

The long-term forecast continues on track, with a variable and unsettled pattern ahead. The interaction between a high surface pressure in the Western Atlantic and a surface low induced by an upper-level trough will promote light NE-E winds through the period.
Global model ensembles agree that Thursday will be the wettest day of the forecast period, suggesting above normal Precipitable Water (PWAT) values (around 1.75 inches). Colder 500 mb temperatures (-8 to -9 Celsius) and jet dynamics around 250 mb with speed near 70 knots will bring ventilation and instability aloft, supporting deep convection activity. As the mid to upper level trough migrates eastward, drier air will filter into the region, inhibiting deep convection activity. Additionally, temperatures in the 500 mb layer should increase to seasonal values (around -7 Celsius). Although global model ensembles tend to a "drier" pattern this weekend, there's still enough low to mid level moisture available for afternoon convection. With the expected weather conditions, soils saturated, local effects, and diurnal heating, the potential of flooding will remain limited to elevated through this period, with showers during the morning along windward sections and afternoon convection over interior and western/southwestern Puerto Rico each day. Rainfall accumulations will most likely promote ponding of water in roadways and poorly drained areas, as well as urban and small stream flooding.

With the NE-E wind flow dominating the period, 925 mb temperatures should remain near below normals.

AVIATION
(18z) TAFS

SHRA/TSRA will continue to impact the local flying area throughout the forecast period. Terminals could be affected by this activity, producing periods of MVFR or even IFR. Thus, TEMPOs will be mainly required for the following time frames: 18-23z across JBQ/JSJ and 06-12z near IST/ISX/JSJ. Winds will prevail around 12 kt, mainly from the SE under sea breeze variations, becoming calm to light and variable after 28/23z, returning from the ESE at around 10 kt after 29/13z with sea breezes.

MARINE

Light to moderate east to southeast winds will prevail through tomorrow, turning from the northeast by Tuesday night. A deep layer trough will continue to promote an unstable weather pattern across the local waters. Showers and thunderstorms are expected to persist, producing localized hazardous marine conditions, small craft should exercise caution.

BEACH FORECAST

Life-threatening rip currents will develop along the exposed north-facing beaches due to pulses of a fading long period northeasterly swell. The moderate risk of rip currents will prevail for the next few days for the beaches in northern Puerto Rico, Culebra, and possibly St. Thomas and St. John in the U.S.
Virgin Islands.

SJU WATCHES/WARNINGS/ADVISORIES
PR...None.
VI...None.
AM...None.