976
FXCA62 TJSJ 090735
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
335 AM AST Sun Nov 9 2025

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

.KEY MESSAGES...
Issued at 300 AM AST Sun Nov 9 2025

* An easterly wave will elevate the flooding risk over portions
  of eastern Puerto Rico with numerous showers and isolated
  thunderstorms today.

* Increased frequency of passing showers across the US Virgin
  Islands today as the easterly wave moves across the forecast
  area.

* Small crafts should exercise caution due to choppy seas while
  swimmers need to avoid high-risk beaches due to a moderate risk
  of rip currents.

* Improving weather conditions across Puerto Rico and the US
  Virgin Islands from Monday onwards, with no significant weather
  threats anticipated through at least the end of the workweek.

&&

.Short Term(Today through Tuesday)...
Issued at 300 AM AST Sun Nov 9 2025

During the overnight hours, mostly calm weather prevailed across the
islands and the most active weather over the Caribbean waters. The
first few showers associated with the approaching easterly wave that
reached the islands, produced minimal rainfall accumulations over
the US Virgin Islands and eastern Puerto Rico. Most weather stations
reported between 0.10 and 0.30 inches of rain. Overnight
temperatures stayed in the upper 70s to low 80s across coastal
areas, while higher elevations remained in the upper 60s to low 70s,
similar to previous nights. Winds were generally SE and variable at
times, with the official weather stations at Henry E. Rohlsen
Airport (St. Croix) and Cyril E. King Airport (St. Thomas) recording
gusts near 23 knots as the wave continued to approach from the east.

For today, winds are expected to increase as the easterly wave moves
across the local area. The latest model guidance indicates
precipitable water (PWAT) values near or above the 75th percentile,
along with enhanced 700 to 500 mb (mid-level) relative humidity.
These conditions favor scattered to numerous showers and
thunderstorms, some capable of producing frequent lightning and
locally heavy rainfall. The eastern half of Puerto Rico is expected
to experience the most active weather as the wave passes through.
Ponding of water on roadways, as well as an elevated risk for urban
and small stream flooding, are possible in areas receiving the
heaviest rainfall.

By Monday, the wave will move west of the region, leading to gradual
improvement in weather conditions. A mid- to upper-level ridge will
then build, promoting a trade wind inversion near 900 mb and PWAT
values decreasing to around 1.0 inch. While passing showers may
still affect the eastern sections due to lingering moisture, overall
stability will increase. Daytime heating and local effects could
still trigger isolated afternoon showers across western Puerto Rico,
but the flooding risk will remain low and localized.

By Tuesday, fair conditions are expected under the influence of the
ridge pattern. Trade winds will remain moderate to occasionally
breezy, with mostly sunny to partly cloudy skies. Any showers that
develop will be brief and mainly concentrated over the interior and
western portions of Puerto Rico during the afternoon.

Temperatures will continue seasonably warm, with highs in the mid to
upper 80s across coastal and urban areas and lows in the mid-70s. In
the mountains, expect lows in the upper 60s to low 70s. Areas that
remain under cloud cover or frequent showers will likely experience
slightly lower daytime highs.

&&

.Long Term(Wednesday through Sunday)...
Issued at 300 AM AST Sun Nov 9 2025

A mid- to upper-level ridge will prevail across the local islands
through the forecast cycle, with some weakening anticipated
toward the end of the period as a polar trough and its associated
frontal boundary move across the western and central Atlantic. At
the surface, a broad high-pressure system positioned northeast of
the islands will maintain easterly winds through at least the end
of the workweek. However, as the aforementioned surface front
approaches the area, winds are expected to veer to east-southeast
and become light and variable. Under the subsidence associated
with the ridge aloft, precipitable water values are expected to
remain below normal for much of the workweek. However, an increase
in PW values is expected over the upcoming weekend as the ridge
aloft weakens and the surface front moves closer to the local
islands.

As a result, a seasonable weather pattern is anticipated across Puerto
 Rico and the U.S. Virgin Islands, with a few passing showers
affecting portions of eastern Puerto Rico, Culebra, Vieques, and
the U.S. Virgin Islands during the nighttime and early morning
hours, followed by limited afternoon convection across western and
interior Puerto Rico. Additionally, seasonable temperatures will
prevail, with daytime highs reaching the mid-to-upper 80s across
coastal and lower-elevation areas.

Overall, no significant weather threats are currently anticipated.
However, the flooding potential may increase toward the end of
the period due to moisture advection associated with the
approaching frontal boundary.

&&

.AVIATION...
(06Z TAFS)
Issued at 300 AM AST Sun Nov 9 2025

VFR conditions across all TAF sites through most of the period.
However, as the tropical wave approaches the local area, an increase
in SH and VCTS is expected, particularly affecting TJSJ, TIST, and
TISX with periods of MVFR condt possible after 09/10Z. Brief
reductions in visibility and low ceilings are likely with the
heavier activity. VCTS possible over TJPS and TJBQ after 09/17Z with
the local effects. Surface winds will be from the east to southeast
(E-SE) at 1216 knots, with occasional gusts up to 23 knots
developing between 09/13Z and 09/14Z. Winds will remain gusty at
times near the rainfall activity.

&&

.MARINE...
Issued at 300 AM AST Sun Nov 9 2025

A surface high pressure across the north central Atlantic will
promote easterly winds, becoming moderate to locally fresh through
Monday. Additionally, an increase in shower and thunderstorm
activity is expected today as an easterly wave moves across the
eastern Caribbean.

&&

.BEACH FORECAST...
Issued at 300 AM AST Sun Nov 9 2025

A moderate risk of rip currents will continue to prevail across
most of the shorelines of Puerto Rico and the U.S. Virgin Islands
through at least Tuesday. Therefore, life-threatening rip
currents are possible in the surf zone, particularly near piers,
jetties, and channels. Conditions are expected to deteriorate by
the end of the workweek.

&&

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

$$

SHORT TERM/AVIATION...MMC
LONG TERM/BEACH FORECAST/MARINE....OMS