650
FXCA62 TJSJ 020900
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
500 AM AST Sun Nov 2 2025

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

.KEY MESSAGES...
Issued at 500 AM AST Sun Nov 2 2025

* Drier and more stable airmass will dominate. Expect limited
  shower activity mainly over interior and western Puerto Rico
  during the afternoons in the next few days.

* Across the U.S. Virgin Islands, mainly fair weather is
  expected, with brief passing showers possible at times.

* Breezy east to east-southeast winds will persist through around
  Monday night, especially across coastal areas.

* A moderate risk of rip currents continues for most local
  beaches, and Small Craft Advisories remain in effect for the
  Mona Passage and offshore Atlantic and Caribbean waters, as
  rough seas persist through at least this afternoon.

&&

.SHORT TERM (Today through Tuesday)...
Issued at 500 AM AST Sun Nov 2 2025

The tropical wave that moved over the islands yesterday and promoted
deteriorated weather is now well west of Puerto Rico as drier air
continues to filter in from the east. Since midnight, radar
estimated accumulations concentrated mainly over the western third
of Puerto Rico, with accumulations also detected over north-central,
eastern interior and eastern Puerto Rico, as well as over Culebra
and coastal areas of St. Croix. The highest radar estimated
accumulations since midnight (1.30 in) were observed over and near
Las Tinajas, Cabo Rojo. Lows were in the low to mid 70s across
central and western lower elevations of Puerto Rico, in the mid 70s
to low 80s across eastern lower elevations of Puerto Rico, and in
the mid 60s to low 70s at higher elevations of Puerto Rico. Lows
were in the upper 70s to low 80s at the USVI, Vieques and Culebra.

Current satellite derived precipitable water (PWAT) imagery indicate
that the drier airmass filtering into our region has around 1.40 to
1.50 in of precipitable water, below normal to low end normal values
for this time of the year. Most of this available moisture is capped
at 850 mb. The more humid moisture field, with PWAT values above
1.80 to 1.90 in, associated with the past tropical wave, will finish
moving westward out of western Puerto Rico early this morning,
leaving this drier airmass to dominate today and promote improved
weather conditions. Current model guidance suggests patches of low
level moisture moving in from the east today and pushing PWAT values
back to normal values, above 1.50 in, this will promote shallow
passing showers at times across windward areas during the morning
and overnight hours. Environmental conditions will also serve to
suppress today`s afternoon convection over interior to
western/northwestern Puerto Rico (500mb temperatures, for example,
are forecast at 2 SD above normal). Available moisture will only
increase under patches of more humid air moving over the islands
from time to time during the period, resulting in passing showers
over windward areas and possible western afternoon convection.
Patches of PWAT values above 1.90 inches are possible tomorrow
(aiding tomorrow`s afternoon convection over interior to western PR
and downwind of the local islands), with drier air on Tuesday,
according to the latest model guidance. Steering flow in general
will continue from the ESE today as a high pressure system over the
central Atlantic gradually moves northward. This steering flow is
forecast to become more easterly late tonight and through late
Tuesday, when more ENE winds are possible. Up to breezy conditions
today, especially at windward coastal areas, with gradually
decreasing speeds as the period progresses. 925 mb temperatures
should be at mainly normal values today, leaving only up to a
limited heat risk for the area.

&&

.LONG TERM (Wednesday through Sunday)...
Issued at 500 AM AST Sun Nov 2 2025

Based on the latest model guidance, the wind pattern will be
primarily influenced by a strong high-pressure system over the
central Atlantic, promoting winds with an easterly component
through most of the period. Aloft, a mid-level ridge is expected
to persist north of the region, maintaining stable and relatively
dry conditions. However, an upper-level low moving south of the
area, over the Caribbean waters, will slightly weaken atmospheric
stability and induce weak surface troughs.

Precipitable water (PWAT) guidance indicates that moisture content
will fluctuate between near to below normal levels for much of the
period, with patches of low-level moisture periodically moving
into Puerto Rico and the U.S. Virgin Islands. As a result, there
will be a low to medium chance (2040%) of brief passing showers
across the windward portions of the U.S. Virgin Islands and
eastern Puerto Rico during the morning hours, followed by
afternoon convection over western Puerto Rico (5060%) driven by
local effects, available moisture, and marginal instability
through Friday. During this time, the flood threat remains
limited, with ponding of water on roads and in poorly drained
areas possible. By Saturday and Sunday, a tropical wave is
expected to increase moisture and wind speeds across the eastern
Caribbean, resulting in a higher chance of showers and a potential
increase in flood risk. Additionally, a limited heat risk is
likely to persist.

&&

.AVIATION...
(06Z TAFS)
Issued at 500 AM AST Sun Nov 2 2025

VFR conditions expected. Brief and isolated SHRA can move at the
VCTY of eastern terminals during the morning hours and at the VCTY
of TJBQ during the afternoon. ESE winds up to around 15 kts with
higher gusts after 02/12Z, gradually becoming more E as the period
progresses and decreasing after 02/23Z.

&&

.MARINE...
Issued at 500 AM AST Sun Nov 2 2025

A surface high pressure over the central Atlantic will promote
moderate to locally fresh trade winds through early this workweek.
Wind-driven, choppy to hazardous seas will prevail through today,
particularly across the offshore Atlantic and Caribbean waters,
and Mona Passage, where Small Craft Advisories are in effect. Seas
improving from this evening onward and winds are forecast gradually
become lighter around Monday night onward.

&&

.BEACH FORECAST...
Issued at 500 AM AST Sun Nov 2 2025

A moderate risk of rip currents is expected today and tonight
across most beaches of Puerto Rico and the U.S. Virgin Islands.
Similar conditions are likely to persist through Monday, with
improvement expected thereafter across most areas, except along
the north-facing beaches of Puerto Rico and Culebra, where the
moderate risk may continue through most of the week. Beachgoers
should exercise caution, as life-threatening rip currents are
possible along the surf zones. Continue monitoring the beach
forecast for updates or changes. For detailed information in your
area of interest, please visit weather.gov/beach.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...None.
VI...None.
AM...Small Craft Advisory until noon AST today for AMZ711.

     Small Craft Advisory until 6 PM AST this evening for AMZ733-741.

&&

$$

MIDNIGHT CREW...MRR/YZR