365
FXCA62 TJSJ 170848
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
448 AM AST Sat Jan 17 2026

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

.KEY MESSAGES...
Issued at 415 AM AST Sat Jan 17 2026

* Breezy to windy conditions could lead for unsecured items to be
  blown around, with outdoor objects potentially displaced in the
  most exposed locations.

* Deteriorating marine and coastal conditions are expected this weekend
  as a northerly swell combines with breezy winds, leading to
  hazardous seas and an increased risk of rip currents, especially
  along northern and northeast-facing beaches.

* Trade wind showers will continue, with a brief increase in
  rainfall activity possible during the afternoon hours, mainly
  across western Puerto Rico, resulting in wet roads and ponding in
  low-lying and poor drainage areas.

&&

.Short Term(Today through Monday)...
Issued at 415 AM AST Sat Jan 17 2026

A band of moisture moved into the forecast area overnight,
increasing cloudiness and producing isolated to scattered showers,
mainly across the northern U.S. Virgin Islands and eastern to
northeastern Puerto Rico, with localized rainfall up to around one-
half inch. Minimum temperatures were cooler than the previous night,
especially across eastern Puerto Rico and southern and western
coastal areas, dropping near 60F in higher elevations and into the
upper 60s along the southern coast. Winds were generally light and
variable, increasing to 1015 mph from the east-northeast with
higher gusts as the moisture band passed, consistent with an
easterly trade-wind disturbance.

Strengthening ENE to E trade winds today will bring breezy to windy
conditions across the region, with gusts occasionally exceeding 30
mph, especially along exposed coasts and higher elevations.
Unsecured items may be blown around, with outdoor objects
potentially displaced in the most exposed locations. These winds
will also push alternating bands of drier and wetter air across the
area, leading to periods of cloudiness and fast-moving showers as
moisture bands pass. Rainfall will be brief and generally light,
though minor ponding in poor drainage areas remains possible, mainly
across northeastern Puerto Rico.

Wind-related hazards will be the primary concern over the next few
days, with winds peaking tonight into Sunday and breezy to locally
windy conditions continuing into early next week, driven by fresh to
strong easterly winds. Shower activity will be limited and brief,
occurring mainly as shallow, fast-moving trade-wind showers due to
dry mid-levels, with minor moisture increases this evening and again
Monday evening. No significant flooding is expected, though brief
ponding remains possible, mainly across eastern and northeastern
Puerto Rico. Outside of passing showers, conditions will generally
be tranquil and favorable for outdoor activities, though those
planning outdoor activities should remain alert for unsecured items
and other wind-related threats, especially in exposed locations.

&&

.Long Term(Tuesday through Saturday)...
Issued at 415 AM AST Sat Jan 17 2026

Model guidance continues to support a transition toward a wetter
and more unsettled pattern beginning Tuesday and persisting through
at least Friday, with the most active period expected after
Wednesday. Precipitable water values are forecast to increase to
above 1.75 inches, which is in the range of  above normal values
for this time of year and indicative of a deep tropical moisture
plume over the region. This moisture, combined with persistently
high mid- level relative humidity, will favor frequent shower
activity across the islands. Low-level winds are expected to
remain generally from the east to northeast and sustained in the
17 to 20 mph range, which should help maintain adequate
ventilation while still allowing for periods of locally enhanced
rainfall where showers align with terrain or convergence zones.
Temperatures are forecast to gradually trend back toward seasonal
norms, generally near the 50th percentile for this time of year
after midweek.

Tuesday is expected to mark a gradual transition toward a wetter
pattern. While a drier air mass is forecast to remain well south of
the area, guidance suggests that low concentrations of Saharan
air particles may still intermittently filter across the region.
Despite this, sufficient low- to mid-level moisture should remain
in place to support showers, particularly during the afternoon and
evening hours.

The wettest and most unstable portion of the forecast period is
expected after Wednesday. While 500 mb temperatures are now forecast
to remain closer to normals (around -6 to -7 degrees Celsius),
the combination of anomalously high moisture and enhanced low- to
mid-level convergence will support thunderstorms. Periods of
moderate to locally heavy rainfall will be possible, with showers
capable of redeveloping and frequently filtering over the same
areas for extended durations, and with the heaviest thunderstorm
activity expected during this period. As a result, the threat for
localized flooding will increase, especially in urban and poor
drainage locations.

Overall, while shower coverage and intensity will fluctuate
through the period, the greatest concern remains after Wednesday,
when periods of heavy rainfall may lead to localized flooding,
particularly in urban and poor drainage areas. This same time
frame will also carry the highest risk for lightning associated
with embedded thunderstorm activity. Winds are expected to remain
generally from the east to northeast in the 17 to 20 mph range,
which may limit widespread flooding but still allow for locally
enhanced rainfall in favored areas. Temperatures are expected to
remain near seasonal norms, with no significant heat impacts
anticipated.

&&

.AVIATION...
(06Z TAFS)
Issued at 415 AM AST Sat Jan 17 2026

VFR conds expcd to prevail across all TAF sites thru the fcst pd. A
patch of low-lvl moisture will bring SHRA thru 17/16Z, with another
incrs aft 17/23Z, resulting in fast-moving SHRA that may brfly
reduce CIGs/VIS, though no sig or prolonged restrs are expcd. ENE
winds at 812 kt early will incrs to 1520 kt with gusts arnd 30 kt
aft 17/13Z, with 1020 kt winds persisting aft 17/23Z, resulting in
windy conds, esp at exposed terminals.

&&

.MARINE...
Issued at 415 AM AST Sat Jan 17 2026

A broad surface high pressure will continue to strengthen over the
central Atlantic during the next few days. Fresh to locally strong
east to northeast winds, and the arrival of a long-period northerly
swell will result in choppy to rough seas, leading to hazardous
marine conditions during the weekend.

&&

.BEACH FORECAST...
Issued at 415 AM AST Sat Jan 17 2026

The moderate risk of rip currents along all the northern-exposed
beaches of Puerto Rico and the U.S. Virgin Islands will remain
favorable through this afternoon. However, conditions are
expected to deteriorate afterwards and persist through the
weekend.

Model guidance continues to suggest a northerly swell moving into
the local waters, combining with rough seas generated by breezy
conditions. This pattern will lead to increasingly large breaking
waves and stronger nearshore currents, particularly along the north
and northeast-facing beaches of Puerto Rico, including Culebra, as
well as exposed beaches across the U.S. Virgin Islands.

As a result, a high risk of rip currents will be in effect from
this afternoon into early next week posing hazardous conditions
for swimmers and beachgoers. Beachgoers are urged to exercise
caution, follow guidance from local authorities, and avoid
entering the water in areas under a high rip current risk.

For localized and updated risk levels, visit weather.gov/beach/sju.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk from this evening through late Sunday
     night for PRZ001-002-005-008-012.

VI...High Rip Current Risk from this evening through late Sunday
     night for VIZ001-002.

AM...Small Craft Advisory from 2 PM this afternoon to 2 PM AST Monday
     for AMZ711.

     Small Craft Advisory from 6 PM this evening to 6 PM AST Sunday
     for AMZ712-716-726-733-741.

     Small Craft Advisory from 6 PM this evening to 2 PM AST Monday
     for AMZ723.

&&

$$

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

NWS SJU Office Area Forecast Discussion