Marine Weather and Tide Forecast for Isabela, PR

.Short Term(This evening through Friday)...
Issued at 219 PM AST Wed Jul 15 2026

Mostly fair conditions persisted across the CWA, with few pockets of showers moving across regional waters. Based on the latest GOES AOD, moderate to isolated high concentrations of Saharan Dust continued to spread across the islands, bringing hazy skies and reduced visibility. As of 1 PM AST, maximum temperatures have been fluctuating between the upper 80s and the low 90s across urban and coastal areas of the islands, with ASOS reporting between 88 and 90 degrees Fahrenheit. Breezy conditions continued in the morning, with wind gusts between 20 and 25 mph, and isolated areas reaching 30 mph, including the AWOS station at the Mercedita airport in Ponce.
For this afternoon, HIRES models suggest the development of showers and isolated thunderstorms across portions of interior and western/southwestern Puerto Rico, though rainfall accumulations shall remain limited and should not pose a flooding threat.

Latest satellite-derived images, the local area remains drier than normal, with PWAT values between 1.2 and 1.4 inches, with the surface high pressure over the central Atlantic promoting E-ESE winds. Based on the NASA Dust AOT model, concentrations of Saharan Dust should gradually diminish late tonight, becoming low by early tomorrow. While there’s a break in Saharan Dust, shower and thunderstorm activity is expected to increase tomorrow as a surface disturbance and an upper-level low approach the CWA From the latest model guidance, PWAT values should increase between 1.5 and 1.7 inches, seasonal for this time of the year. Looking at the cross- section, the highest RH lies in the low and high levels, while the mid-levels remain dry (likely below 30 %). Due to the proximity of the trough, mid-level temperatures should remain cool (between -6 and -7 degrees Celsius), while introducing slight instability across the local area. Although the Galvez-Davison Index suggests low potential for scattered thunderstorms, at most, shallow convection, the main trigger for any convection could be daytime heating combined with local effects and sea breeze convergence. Hence, expect shower activity over windward sections of the islands during the morning, with afternoon convection over interior and western Puerto Rico. Additionally, local island streamers will bring additional rainfall across portions of eastern Puerto Rico, including the San Juan Metropolitan Area. Given the expected conditions, rainfall accumulations could lead to ponding of water over roadways and poorly drained areas, along with minor flooding over the aforementioned areas. As the disturbance continues to move westward, drier conditions, along with low to isolated moderate concentrations of Sahara Dust, should return on Friday, limiting shower activity. Seasonal temperatures will continue across the islands, with maximum temperatures reaching upper 80s and low 90s over urban and coastal areas, while interior portions may range between upper 70s and mid 80s. Heat indices may exceed 100 degrees Fahrenheit, leading to a limited to elevated heat threat across the islands.

.Long Term(Saturday through next Tuesday)...
Issued at 219 PM AST Wed Jul 15 2026

Typical summertime weather is expected through the weekend as weak upper-level ridging maintains warm and humid conditions with isolated showers in the afternoon over western PR, while the rest of the islands will remain dry each day.

Beginning Sunday and continuing through Tuesday, a weak upper- level trough will gradually cool temperatures aloft and weaken the ridge, allowing atmospheric instability to increase. As a result, afternoon and evening thunderstorms are expected to increase from isolated to scattered at times, with Monday and especially Tuesday offering the greatest coverage of rainfall. While widespread severe weather is not anticipated, locally heavy downpours may result in brief ponding of water on roadways, particularly in urban and poor drainage areas. Frequent showers and occasional lightning will remain the primary hazards.

Each day, visitor and locals should experience warm conditions through the period as low-level temperatures remain above seasonal averages. Afternoon heat indices will likely exceed normal values, especially across urban and coastal locations. People are urged to stay hydrated, seek shade or air conditioning during the hottest part of the day, and limit prolonged outdoor exertion.

AVIATION
(18Z TAFS)
Issued at 219 PM AST Wed Jul 15 2026

Mostly VFR conds shall cont today across all terminals, with HZ and VIS around 6SM due to SAL across the local area. -SHRA may move across S-SW PR, leading to VCSH across JPS. SAL concentrations should gradually diminish aft 15/23z, with VIS returning to P6SM for the rest of the prd. A disturbance approaching the CWA will increase VCSH across most TAF sites aft 16/12z and may reduce CIGs /VIS. E-ESE winds btwn 14 - 18 kt will continue through 12/23z, becoming light and possbly VRB at JPS, strengthening btwn 15 - 20 kt and gusts up to 28 kt aft 16/13z.

MARINE
Issued at 219 PM AST Wed Jul 15 2026

A surface high over the central Atlantic interacting with the Panama–Colombia Low will maintain a tight pressure gradient across the region, supporting moderate to fresh east to east-southeast winds and moderate to choppy seas through the rest of the week.
Moderate concentrations of Saharan dust embedded within a drier air mass will continue to spread across the region today, resulting in hazy skies and locally reduced visibility. However, dust concentrations will gradually decrease from tonight into Thursday as a trade wind perturbation approaches the region on Thursday. This perturbation will increase the potential for showers and isolated thunderstorms, particularly during the afternoon over western Puerto Rico.

BEACH FORECAST
Issued at 219 PM AST Wed Jul 15 2026

A low risk of life-threatening rip currents is expected through Friday across Puerto Rico and the U.S. Virgin Islands. Although the risk is low, dangerous rip currents can still occur, especially near groins, jetties, reefs, and piers. Always swim near a lifeguard whenever possible and heed the advice of local beach patrols and beach warning flags. By Friday, the rip current risk will increase to moderate along portions of the north, east, and southeast-facing beaches of Puerto Rico, Vieques, Culebra, and St. Croix and continuing into the weekend. Beachgoers should continue to swim near lifeguards whenever possible, heed beach warning flags, and never swim alone

A limited to elevated extreme heat risk is also expected at most local beaches today through the rest of the week. Stay well hydrated, seek shade whenever possible, and apply sunscreen to help reduce the risk of heat-related illnesses.

FIRE WEATHER
Issued at 219 PM AST Wed Jul 15 2026

An elevated fire danger risk is forecast across the regional islands today. Under the influence of a dominant dry air mass and Saharan dust, minimum relative humidity (RH) values are expected to drop into the low-to-mid 40s across the southern plains, and into the low 50s across portions of northern and eastern Puerto Rico during the peak heating hours of the day. At the same time, easterly winds will persist at 10 to 15 mph with stronger, gusty conditions expected.

Given the combination of dry soils, low RH values, and breezy conditions, any fires that develop could spread rapidly.
Consequently, a Fire Danger Statement (RFD) has been issued and will remain in effect today from 10:00 AM to 4:00 PM AST for the southern plains, as well as northern and eastern sectors of Puerto Rico.

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