Carolina, PR 00983 Weather

: New SHORT TERM, LONG TERM, AVIATION, MARINE, BEACH FORECAST:

Key messages

Issued at 254 AM AST Sat Oct 31 2026

* Unsettled weather conditions are expected later today and tonight, so pack and umbrella if your are planning to go out for candy. Be prepared to look for shelter in case thunderstorms develop.

* Heat indices above 100 degrees are expected to persist, with increasing temperature expected by mid-week. Take plenty of breaks when outdoors and stay hydrated.

* Passing showers are expected for the Virgin Islands as well, but the risk of flooding is limited to none.

.Short Term(Today through Monday): Issued at 254 AM AST Sat Oct 31 2026

The night was quiet across the northeastern Caribbean. A few showers managed to reach portions of the Virgin Islands and southeastern Puerto Rico, but accumulations were not significant. Once again, temperatures cooled down to the low 80s and 70s for coastal areas, and in the 60s across the Cordillera Central.

An upper level trough axis remains south of Hispaniola. This feature will pull moisture into the region today, causing increasing showers in the afternoon and evening hours. The area of above normal precipitable water is very evident in satellite imagery. Pack an umbrella if you are planning to collect candy tonight, and be ready to seek for shelter if you hear thunder. The first round of showers will be the usual afternoon convection developing in the interior and west-southwest, were there is a moderate risk of flooding, like almost every afternoon. Later tonight, showers will increase along coastal areas of southern and eastern Puerto Rico, and also in the vicinity of the Virgin Islands.

To start November on Sunday, this trough will bring plenty of clouds into the area. The dynamic aloft is somewhat conducive for showers formation, but there is some dry air intrusion at the lower levels. Additionally, cloud coverage may reduce the amount of solar radiation received and hinder local effects. Regardless, due to the uncertainty that these troughs bring, the probability of precipitation was left at 60 to 70%, with a moderate risk of urban and small stream flooding. The reasoning is that even with strong cloud coverage, the trade winds will still carry showers and thunderstorms into the local area. There is a risk of frequent lightning as well with the thunderstorm activity.

The temperature profile still indicate above normal values for this time of year. For today, the normal high is 88 and normal low is 76 at the San Juan Area climate site. Elevated heat indices, in those areas where the sun may peek, will cause issues for those very sensitive, especially when outdoors and without effective cooling or hydration.

.Long Term(Tuesday through Saturday): Issued at 254 AM AST Sat Oct 31 2026

A generally warm and humid weather pattern is expected across Puerto Rico during the long term period. Precipitable water values will remain relatively high, ranging between 1.9 and 2.3 inches, while low-level relative humidity (850 to 700 mb) will generally remain between 70% and 85%. Mid-level moisture (700 to 500 mb) also shows periods of increased humidity, mainly values in the 75th percentile based on climatology for the month of November. Notably, 925 mb temperatures are forecast to reach approximately two standard deviations above normal at the beginning of the period (particularly Tuesday and Wednesday), supporting warmer than normal conditions. If widespread cloud cover does not develop, these warm and humid conditions could promote stronger daytime heating and enhance afternoon convection. At the surface, light and variable winds are expected, particularly from Wednesday through Friday, resulting in very weak steering flow. This will allow locally developed showers to move slowly, increasing rainfall accumulations and the potential to observe flooding. Sea-breeze convergence, diurnal heating, and orographic lifting across the interior and western portions of Puerto Rico could further enhance shower development. Periods of heavy rainfall could lead to urban and small stream flooding and quick river rises.

At the upper levels, no significant changes in the overall pattern are expected initially, although current global models show some disagreement regarding the long term evolution. An upper-level low, also reflected in the surface pattern and associated frontal boundary, is forecast to swing north of the region across the Atlantic waters. Toward the end of the week, its influence could promote a shift in low-level winds from the south, bringing additional tropical moisture into the region and maintaining a warm and humid environment. Meanwhile, 500 mb temperatures will remain near -5 to -6C, with generally moderate lapse rates suggesting some potential for atmospheric instability. Cloud cover will play an important role in afternoon convective development, as extensive cloudiness could limit surface heating and inhibit convection, while periods of sunshine would favor stronger daytime heating and enhance shower development. Overall, expect warm and humid conditions, variable cloud cover, and periods of showers, particularly across interior and western Puerto Rico. Given the weak steering flow and potential for slow-moving showers, locally heavy rainfall, increased rainfall accumulations, and flooding impacts will remain possible. Continue to monitor the forecast as confidence increases and updated become available.

Aviation

(06Z TAFS) Issued at 254 AM AST Sat Oct 31 2026

Mainly VFR conditions are expected to prevail this morning. SHRA will increase after 17Z for the Cordillera Central, causing mountain obscuration. Periods of reduced VIS and low ceilings are expected for TJPS at times. SHRA will increase after 22Z for the Caribbean Sea and the USVI terminals. These showers could cause interruptions to operations. Winds are from the SE at 10 kts or less, shifting slightly from the NE after 15Z at 1-3 kft, remaining from the SE above 5 kft.

Marine

Issued at 254 AM AST Sat Oct 31 2026

Surface high pressure over the central Atlantic will continue to promote moderate east to southeasterly winds across the regional waters during the weekend. Seas will remain between 1 to 3 feet during the next few days, with ocasional higher seas near the heavy rainfall and thunderstorms. Expect choppy conditions at times across portions of the offshore waters and local passage reducing visibility and generating gusty winds.

Beach forecast

Issued at 254 AM AST Sat Oct 31 2026

A moderate risk of rip currents will continue during the next several days along the northern beaches of Puerto Rico and Culebra, as well as the US Virgin Islands. This means life-threatening rip currents are possible in the surf zone. Beachgoers should remain cautious. Expect periods of afternoon showers and thunderstorms, particularly across northwestern and northern Puerto Rico. If you hear thunder, seek shelter immediately inside a sturdy building.

Watches, warnings and advisories

PR: None. VI: None. AM: None.