696
FXCA62 TJSJ 151804
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
204 PM AST Thu Jan 15 2026

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

.KEY MESSAGES...
Issued at 200 PM AST Thu Jan 15 2026

 * A variable weather pattern is forecast for the upcoming days,
   with passing showers along eastern sections of Puerto Rico and
   the U.S. Virgin Islands during the morning and evening hours.

 * For Friday and into the upcoming weekend, wetter-than-normal conditions
   persist, with showers more frequent, resulting in wet pavement
   and low-lying flooding.

 * A strengthening to a moderate breeze is forecast by Friday
   afternoon into the weekend. Please secure outside objects.

 * An increase in rip current risk is forecast for the northern,
   exposed beaches.

&&

.Short Term(This evening through Saturday)...
Issued at 200 PM AST Thu Jan 15 2026

During the morning hours, variable weather conditions prevailed
across the region. Under an east-southeasterly low-level wind flow,
increased cloud cover and passing showers were observed across
southern and eastern portions of Puerto Rico, including the San Juan
metro area, as well as the smaller surrounding islands. Some of
these showers were briefly moderate to heavy but moved quickly, with
rainfall generally remaining below half an inch. Conditions
gradually improved at times between showers, with occasional breaks
in cloud cover.

The forecast continues on track. A polar trough and its associated
frontal boundary will remain well northwest of the local area, while
ridging aloft persists across the northeastern Caribbean. Although
the mid-level ridge is expected to shift slightly northward during
the period, it will continue to influence the region, maintaining
generally weak large-scale forcing. At the surface, east-
southeasterly trade winds will persist through at least Friday,
promoting the continued transport of moisture across the islands.

This pattern will support scattered showers, with activity favored
across eastern and southeastern Puerto Rico during the late morning
and early afternoon hours. By mid to late afternoon, shower
development is expected to shift toward the interior and
western/northwestern portions of Puerto Rico due to local effects
and sea breeze convergence. Rainfall impacts should remain limited
overall; however, brief ponding of water on roadways and isolated
urban flooding will be possible where showers repeat.

By Friday night into Saturday, winds are forecast to gradually
strengthen and veer toward the east-northeast as a trade wind
perturbation crosses the region. This will result in more frequent
trade-wind showers, especially across windward coastal areas. While
rainfall amounts should generally be modest, localized brief ponding
and very localized flooding will remain possible. Breezy conditions
may also cause unsecured items to blow around.

&&

.Long Term(Sunday through next Wednesday)...
Issued at 200 PM AST Thu Jan 15 2026

The inherited forecast remains unchanged. On Sunday morning, winds
will remain breezy but are expected to gradually weaken through
the day. Sunday will remain the driest day of the long-term
period, as precipitable water values decrease to around 1.0 inch,
which is below normal for this time of year. This will support
relatively stable and seasonable conditions, with passing trade
wind showers and limited afternoon convection driven primarily by
local effects.

Beginning Monday, a transition toward a wetter and more unsettled
pattern is expected to develop and persist through much of the
workweek. Precipitable water values are forecast to increase to
around 1.75 inches, which is above normal for this time of year.
From Monday through Wednesday, a subtropical jet streak near 250
mb will enhance upper-level divergence and support the development
of an induced surface trough, resulting in higher shower coverage
across the forecast area under an easterly to northeasterly low-
level wind flow.

Additionally, 500 mb temperatures near -7 degrees Celsius during the
early part of the workweek will allow any rainfall activity that
develops to grow more efficiently in the vertical. This
environment will enhance instability and increase the potential
for isolated thunderstorms, particularly during the afternoon
hours. Current guidance suggests that the first part of the
workweek, as well as the latter portion of the forecast period,
appear to be the wettest, while some variability in rainfall
coverage and intensity is expected in between.

At this time, each afternoon from early in the workweek carries a
limited flood risk, mainly due to the potential for ponding of
water on roads and in poorly drained areas. Forecast updates should
continue to be monitored as some uncertainty remains particularly
by the later part of the workweek.

&&

.AVIATION...
(18Z TAFS)
Issued at 200 PM AST Thu Jan 15 2026

Mainly VFR conditions expected across all terminals. Brief VCSH/SHRA
possible this afternoon into early evening, mainly across TJPS/TJBQ,
with isolated MVFR in heavier showers. Activity diminishes after
sunset. SE-ESE winds 512 kt, locally gusty during the afternoon
with sea breeze variations, becoming lighter overnight and
increasing again aft 16/13z. No significant or prolonged aviation
impacts are expected.

&&

.MARINE...
Issued at 200 PM AST Thu Jan 15 2026

No changes to the inherited forecast. Surface winds continue from
the southeast as the surface high pressure across the central
Atlantic will maintain remain in place over the Central Atlantic
through the end of the workweek. By Saturday, strengthening east
to northeast winds, and the arrival of a long-period northerly
swell will likely result in choppy to rough seas, leading to
hazardous marine conditions during the weekend into the upcoming
workweek. Mariners are urge to exercise caution across the
offshore Atlantic waters and the local passages during Friday and
into the weekend.

&&

.BEACH FORECAST...
Issued at 200 PM AST Thu Jan 15 2026

No changes to the inherited forecast. The moderate risk of rip
currents along all the northern-exposed beaches in Puerto Rico and
the U.S. Virgin Islands will remain favorable through Friday.
Conditions will deteriorate Saturday and Sunday, when energy from
a northerly swell moves in, resulting in breaking waves along all
the north and northeast coasts of Puerto Rico, including Culebra.
As a result, a high risk of rip current is forecast for the
upcoming weekend.

&&

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

$$

SHORT TERM...CVB
LONG TERM....LIS
AVIATION...CVB

NWS SJU Office Area Forecast Discussion