National Weather Service Today's Weather Impact Levels

576
FXCA62 TJSJ 150852
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
452 AM AST Thu Jan 15 2026

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

.KEY MESSAGES...
Issued at 404 AM AST Thu Jan 15 2026

 * Passing showers will continue to affect the easter sections of
   Puerto Rico and the US Virgin Islands during the morning hours.
   Therefore, ponding of water over roads are possible.

 * From Friday into early Saturday, moisture will increase, and the
   frequency of showers is still expected to increase. Especially
   across eastern sections, including the San Juan metro area.

 * There is a moderate risk of rip currents through tomorrow,
   increasing to high on Saturday into Sunday for the north coast
   of Puerto Rico and Culebra.

&&

.Short Term(Today through Saturday)...
Issued at 404 AM AST Thu Jan 15 2026

Showers affected eastern Puerto Rico this evening, initially
isolated, but increased in coverage after midnight. Radar-estimated
rainfall since around 8 PM showed isolated amounts up to one-half
inch across parts of eastern Puerto Rico. Patches of mid- to high-
level clouds were observed, with overall cloudiness increasing
alongside the shower activity. Overnight low temperatures remained
warmer than normal, with readings in the low 60s across higher
elevations, the upper 70s across lower elevations, and even some low
80s across coastal areas and nearby buoys. Winds were light and
variable over land, while a general moderate ESE flow persisted
across the regional waters.

Today will feature moderate ESE trade winds veering to the SE as the
surface high shifts farther away from the region, allowing a warmer
air mass to remain in place. High temperatures are expected to reach
the mid to upper 80s across many coastal and urban areas. In the
meantime, moisture will gradually increase as the mid-level ridge
lifts northeastward and the inversion weakens. These conditions will
support scattered showers, with morning activity continuing over
exposed east to southeast sections. During the afternoon, showers
are expected to develop, with focused across northern and
northwestern Puerto Rico, as well as downwind of the local islands,
following the dominant southeasterly flow. Rainfall impacts should
remain limited, though brief ponding of water and isolated urban
flooding are possible where showers repeat.

Conditions will remain relatively quiet tonight, with gentle winds,
warm temperatures, and less frequent passing showers, despite
increasing moisture. On Friday, wetter-than-normal conditions
persist, with light winds in the morning strengthening to a moderate
breeze by afternoon. While morning activity remains limited, weak
steering flow and abundant moisture will favor slow-moving scattered
to locally numerous afternoon showers, mainly across western
interior and western Puerto Rico, with the potential for isolated
thunderstorms producing lightning and locally heavier downpours.
Friday night into Saturday, winds will strengthen further and
gradually back from easterly to east-northeasterly, transitioning
the pattern toward a more wind-driven regime. On Saturday, fresh to
locally strong east-northeasterly winds will support more frequent
trade-wind showers, cooler temperatures, and increasing wind-related
hazard risks, especially along exposed coastal areas. Overall
impacts should remain localized, with brief ponding or isolated
flooding, a lightning risk on Friday, and non-thunderstorm wind
impacts increasing into Saturday.

&&

.Long Term(Sunday through Thursday)...
Issued at 404 AM 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...
(06Z TAFS)
Issued at 404 AM AST Thu Jan 15 2026

VFR conditions will prevail across all TAF sites through the
forecast period. Periods of -RA/-SHRA will affect the USVI terminals
and TJSJ through 15/14Z, with brief MVFR visibility and ceiling
restrictions possible. After 15/16Z, shower activity is expected to
shift inland, mainly impacting TJPS and TJBQ. After 15/22Z,
VCSH/SHRA will again affect the USVI terminals and TJSJ. Surface
winds will be light and variable early, increasing to 1015 kt from
the ESESE between 15/14Z and 15/22Z, then becoming light and
variable again thereafter. No significant or prolonged aviation
impacts are expected.

&&

.MARINE...
Issued at 404 AM AST Thu Jan 15 2026

The surface high pressure across the central Atlantic will maintain
gentle to moderate east to southeast winds 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.

&&

.BEACH FORECAST...
Issued at 404 AM AST Thu Jan 15 2026

The moderate risk of rip currents along all the northern-exposed
beaches of Puerto Rico and the U.S. Virgin Islands will prevail
through Friday. Conditions will deteriorate Saturday and Sunday,
when energy from a northerly swell moves in and results 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/AVIATION...ICP
LONG TERM/MARINE/BEACH FORECAST...MMC

NWS SJU Office Area Forecast Discussion