SHORT TERM
Today through Sunday...

Currently, radar and satellite imagery indicate calm and pleasant weather across the forecast area, accompanied by light and variable winds. Throughout the overnight period, some isolated showers have moved over the local waters. Coastal and lower-elevation areas of Puerto Rico are experiencing morning temperatures ranging from the upper 70s to lower 80s, while higher elevations enjoy slightly cooler conditions in the mid 60s to lower 70s. In the U.S. Virgin Islands, temperatures are similarly in the upper 70s to lower 80s.

The unstable and wet weather pattern will persist in the short term.
The latest satellite-derived precipitable water values fluctuate between 1.8 and 2.2 inches today, which is considered normal to above normal. Conditions aloft will be favorable over the next few days, maintaining instability for deep convection development, as a TUTT (Tropical Upper Tropospheric Trough) lingers over the northeast Caribbean. At the surface, light and variable winds will continue throughout the short-term forecast.

For today, expect another day of showery activity during the morning across the U.S. Virgin Islands and the eastern sectors of Puerto Rico. This will be followed by enhanced shower activity due to diurnal heating, leading to another round of showers and thunderstorms, particularly across the Cordillera Central during the early afternoon, spreading toward the coastal areas later in the afternoon. Hazards include frequent lightning, gusty winds, and urban and small stream flooding due to already saturated soils. On Saturday and Sunday, shower activity is expected to be less intense compared to today, but local effects and diurnal heating will still promote afternoon convection, especially in the interior, northwestern, and north-central Puerto Rico.

In addition, an elevated to significant heat risk will persist through the weekend. Guidance indicates temperatures at 925 mb will be two standard deviations above normal values, particularly on Saturday. The combination of high temperatures and humidity could create hazardous heat conditions. A Heat Advisory is in effect for all coastal, urban, and low-elevation areas of Puerto Rico, as well as for Vieques, Culebra, and the U.S. Virgin Islands. Residents and visitors should monitor the forecast and take precautions to stay hydrated by drinking plenty of water, wearing light and breathable clothing, and avoiding prolonged sun exposure, especially during peak heat hours.

In summary, moisture and favorable conditions aloft will lead to additional showers and isolated thunderstorms today, with a broader area likely experiencing limited to elevated flooding and lightning risks. Local effects and diurnal heating will continue to promote afternoon convection in some areas over the weekend. Hot conditions are likely to persist in the coming days.

LONG TERM
Monday through Thursday...

A deep-layered trough will continue to dig just north of the Caribbean islands. This through will act to maintain a weak steering flow, with speeds of 1 to 5 knots on Monday and Tuesday.
The through will gradually moves away by mid-week, with winds gradually recovering speed, but only to around 10 knots. At the surface, induced patches of moisture will move from time to time through the period, although there are no particular day with a great amount of low level moisture. This moisture will act to generate some showers reaching the coastal areas of Puerto Rico and the Virgin Islands each day. However, the strongest activity, with thunderstorms, is expected each afternoon across the Cordillera Central, with the activity then drifting toward the coast. Since the winds will be so weak, it is difficult to determine which area is going to be more affected, aside than the interior that should receive the bulk of the activity each day.

As it has been the case in the past couple of weeks, above normal temperatures will persist in the area, with the threat of excessive heat each day. This heat will mainly impact those without effective cooling or adequate hydration.

AVIATION
(06Z TAFs)

Mainly VFR conditions are expected to prevail throughout the morning forecast period, with visibility concerns likely at TJSJ and U.S.
Virgin Islands TAF sites. After 20/1700Z, additional activity is anticipated to develop in the Cordillera Central, leading to mountain obscuration that may affect TJPS. Winds will remain light and variable, shifting to a southerly component at around 5 to 8 knots or less, becoming calm or light/variable after 20/2300Z.

MARINE
A weak surface low pressure to the northeast of the region will maintain weak and variable winds throughout early next week. Showers and isolated thunderstorms will persist across the regional waters, particularly off the western and southern coastal waters of Puerto Rico each afternoon.



BEACH FORECAST
The moderate rip current risk will persist for the northern coast of Puerto Rico, Culebra, and some beaches in northwestern St. John and eastern St. Croix.

SJU WATCHES/WARNINGS/ADVISORIES
PR...Heat Advisory from 10 AM this morning to 4 PM AST this afternoon for PRZ001>003-005-007-008-010>013.

VI...Heat Advisory from 10 AM this morning to 4 PM AST this afternoon for VIZ001-002.

AM...None.