National Weather Service Today's Weather Impact Levels

577
FXCA62 TJSJ 110913
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
513 AM AST Sun Jan 11 2026

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

.KEY MESSAGES...
Issued at 500 AM AST Sun Jan 11 2026

* A moderate risk of rip currents continues along the north facing
  beaches of Puerto Rico and Culebra today.

* A typical trade-wind pattern will bring passing showers to
  windward areas of Puerto Rico and the U.S. Virgin Islands,
  mainly overnight and early in the morning, with afternoon
  showers, especially across southwestern Puerto Rico. Localized
  ponding or minor flooding is possible in poor drainage areas of
  Puerto Rico and the U.S. Virgin Islands.

* Near-seasonal temperatures will continue across Puerto Rico and
  the U.S. Virgin Islands, with comfortable daytime temperatures
  for outdoor activities through around mid-week, then guidance
  indicates above-normal temperatures for end of the week.

&&

.Short Term(Today through Tuesday)...
Issued at 500 AM AST Sun Jan 11 2026

Southern and western Puerto Rico, as well as St. Croix, observed
mostly clear skies with pleasant temperatures. In contrast, the
northern U.S. Virgin Islands and the north and east Puerto Rico
experienced occasional fast-moving showers, producing periods of
moderate to locally heavy rainfall overnight. Minimum temperatures
ranged from the low 70s across coastal areas to the low 60s, and
locally lower, across interior valleys and mountainous regions.
Winds were generally from the northeast at around 5 mph, with
localized land-breeze variations.

A mid- to upper-level trough continues to move eastward away from
the northeastern Caribbean into the Atlantic, periodically
perturbing the trade wind flow. These perturbations will support
intermittent moisture surges, resulting in passing showers across
windward areas of Puerto Rico and the U.S. Virgin Islands over the
next few days. Meanwhile, a surface high pressure north of the
region will shift farther east as a weak, surface-induced trough
moves through the local area. This pattern will allow low-level
winds to veer slightly more easterly at times; however, a prevailing
northeasterly steering flow is expected to persist.

Under this synoptic setup, a typical trade-wind advective pattern is
anticipated today through Tuesday. Evening and morning showers will
mainly affect windward and coastal areas, followed by afternoon
convection driven by local effects, primarily across western Puerto
Rico each day, where we cannot rule out one or two thunderstorms.
Rainfall impacts are expected to remain limited overall, though
brief periods of moderate to locally heavy rainfall are possible
with passing showers, particularly along windward locations. Across
western Puerto Rico, localized ponding of water on roads and in
poorly drained areas may occur during afternoon convection. While
widespread flooding is not anticipated, isolated urban flooding
cannot be ruled out.

&&

.Long Term(Wednesday through Sunday)...
Issued at 500 AM AST Sun Jan 11 2026

During the long-term period, a deep-layer mid to upper-level
trough will continue shifting eastward away from the Lesser
Antilles, while a weak mid to upper-level ridge builds over the
northeastern Caribbean. Precipitable water values are forecast to
range between 1.4 and 1.9 inches, near to above climatological
normal for this time of year, with peak moisture expected on
Friday.

Low-level winds will generally remain from the east to southeast
through Friday, then shift to the east-northeast on Saturday and
Sunday while increasing in speed. Model guidance suggests a
frontal boundary will remain north of the region, while a pre-
frontal trough may enhance moisture convergence and atmospheric
instability, supporting a wetter pattern around Friday and again
next Saturday. At this time, Friday appears to present the highest
rainfall potential, with a limited flood risk mainly across
western Puerto Rico during the afternoon hours. Isolated thunderstorm
activity cannot be ruled out as mid-level temperatures cool, with
500 mb temperatures decreasing from near -5 degrees C on Wednesday
to around -8 degrees C by the end of the week.

Ensemble guidance continues to indicate above-normal temperatures
across Puerto Rico and the U.S. Virgin Islands throughout the
long-term period.

&&

.AVIATION...
(06Z TAFS)
Issued at 500 AM AST Sun Jan 11 2026

VFR conditions will prevail today. However, occasional -SHRA/SHRA
will move across JSJ/IST/ISX throughout the day, followed by some
activity near JPS during the afternoon. This activity will bring
brief MVFR conditions at these sites. We cannot rule out one or two
TSRA/-TSRA across the interior and SW-PR between 11/16-23z. A
similar weather pattern is possible for tomorrow. Winds will be calm
to light and variable each night, returning from the NE/E at 10-15kt
with higher gusts, and a sea breeze aft 13z.

&&

.MARINE...
Issued at 500 AM AST Sun Jan 11 2026

A surface high pressure moving eastward across the western Atlantic,
combined with a weak surface trough northeast of the region, will
maintain moderate east to northeast winds across the local waters
through the middle of next week. This pattern will support passing
trade-wind showers, mainly across the Atlantic waters, with occasional
showers also moving through the Caribbean passages at times. Wind
flow becoming east to southeast around Thursday and Friday. Toward
the latter part of the workweek and into the weekend, strengthening
winds and the arrival of a long-period northerly swell may result in
choppy and potentially hazardous marine conditions. Mariners are
advised to continue monitoring the forecast.

&&

.BEACH FORECAST...
Issued at 500 AM AST Sun Jan 11 2026

Today, a moderate risk of rip currents is in place for the
northern and eastern beaches of Puerto Rico, as well as Culebra,
with breaking waves around 4 feet. Similar conditions are expected
to persist over the next few days, with the moderate risk at
times extending to the northwestern beaches of Puerto Rico and the
U.S. Virgin Islands. A moderate risk indicates that life-
threatening rip currents are possible within the surf zone.

A low risk will prevail across southern, more protected areas;
however, life-threatening rip currents can still occur near
groins, jetties, reefs, and piers even when the overall risk is
low. For more location-specific information, continue to monitor
weather.gov/beach/sju.

By next weekend, conditions may deteriorate, with the potential
for a high risk of rip currents to return.

&&

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

$$

SHORT TERM/AVIATION...CAM
LONG TERM/MARINE/BEACH...YZR

NWS SJU Office Area Forecast Discussion