Marine Weather and Tide Forecast for Isabela, PR

SHORT TERM
Tonight through Tuesday...

The Doppler Radar detected a few showers across the islands in the morning, with the majority of them over the waters. Later in the morning, as showers slowly dissipated or moved away from the islands, a layer of mid to upper-level clouds moved over, increasing cloudiness and limiting the heat indices from reaching even higher values, and leaving them around 105 degrees Fahrenheit. The suspended Saharan dust particles slowly dissipated throughout the morning hours. Diurnally induced showers and isolated thunderstorms developed downwind from the US Virgin Islands and la Sierra de Luquillo, form the interior to west and southwest PR this afternoon. Maximum temperatures were from the upper-80s to the low-90s across the lower elevations of the islands, and from the mid-70s to low-80s across the higher mountains of Puerto Rico. The wind was from the east to east- northeast between 5 and 15 mph with sea breeze variations and higher gusts.

We expect afternoon convection to continue and isolated thunderstorms may form today. The afternoon activity will continue into the evening, spreading into the waters or dissipating, leaving mainly calm weather overnight. The advection of additional rain will focus primarily on the regional waters and windward locations of PR and the USVI through at least tomorrow (Monday) morning. The Saharan particle concentrations will finally exit the region, with only suspended traces, if any.

A mid to upper-level high pressure will slowly displace today's upper-level trough westward into the western Caribbean and Atlantic, leaving the islands in between these two features on Monday. Thus, a more stable atmosphere will return across the Northeast Caribbean for the beginning of the week. By Tuesday, the mid to upper-level high will build over the islands, increasing even more stability.
Regardless of the stable conditions and hot weather pattern, a few trade wind perturbations with increasing winds will arrive Monday and Tuesday, bringing periods of showers across the windward locations. This moisture increase, with the local effects and sea breeze variations, will promote afternoon thunderstorms across the mountains and western locations of PR, as well as downwind from the US Virgin Islands and from El Yunque into the San Juan Metropolitan area.

LONG TERM
Wednesday through Sunday...

A wet weather pattern is expected for the first half of the long- term forecast due to the approach of a broad tropical wave into the region. This tropical wave is anticipated to reach the islands between Wednesday and Thursday, promoting a high moisture environment and unsettled weather conditions. The latest precipitable water content guidance (PWAT) has values up to 2.10 inches, suggesting a very moist environment beginning by early Wednesday and lasting through late Thursday. Therefore, showers and thunderstorms are likely over portions of eastern, central and western Puerto Rico, and the U.S. Virgin Islands during this period.
After the wave passage, a drier airmass will begin to filter into the region. Nonetheless, pockets of moisture will continue to filter from time to time, promoting isolated to scattered showers over the islands. From Saturday onwards, a mid-level ridge is expected to build near the region, promoting drier conditions and stability aloft.

Recent model guidance continues to suggest the arrival of another pulse of high concentrations of Saharan Air layer (SAL)into the region. This event will also help to inhibit the development of shower across the islands. Be prepared for hazy skies, reduced visibilities and deteriorated air quality through at least the upcoming weekend.

Hot temperatures will remain all week across the area with maximum temperatures reaching upper 80s to low 90s along the coastal and urban areas each day. Heat indices are expected to rise into values above 105 degrees Fahrenheit each day as well, mainly due to the combination of high temperatures and high moisture. Residents and visitors, please be aware of these conditions and plan accordingly if planning to do outdoor activities under sun exposure.

AVIATION
(18Z TAFS)

VFR conditions will prevail across all terminals thru the period.
Visibilities will improve as the SAL exits the region. Isolated trade wind SHRA/-SHRA may briefly affect terminals. Afternoon SHRA/TSRA will develop across the interior and west PR, affecting the VCTY of JPS/JBQ thru 13/23z. A similar wx pattern will prevail tomorrow, with a slight increase in coverage/intensity after 14/16z.
Winds E/ENE at around 15 kt with higher gusts and sea breeze (from E/ESE tomorrow after 14/13z), becoming light/variable after 13/23Z.



MARINE

A surface high pressure across the central Atlantic will continue to promote moderate easterly winds across the region. Moderate to locally fresh easterly winds are expected to return by early next week. Therefore, small craft operators will likely be encouraged to exercise caution. A tropical wave will approach the region by the middle of next week, increasing moisture and the potential to observe showers and thunderstorms.

BEACH FORECAST

Rip current risk remains low across local beaches, but life- threatening rip currents can still form near structures like groins, jetties, reefs, and piers. Always swim near a lifeguard and follow local beach safety guidance.

By late Tuesday, a moderate risk of rip currents will return along north- and east-facing beaches of Puerto Rico, Culebra, Vieques, and the US Virgin Islands, driven by increasing winds.

Hot and humid conditions will continue throughout the week, with heat index values likely around 105°F. Stay hydrated, take breaks in the shade, and limit outdoor activity during peak heat hours.

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