National Weather Service Today's Weather Impact Levels

626
FXCA62 TJSJ 091805
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
205 PM AST Fri Jan 9 2026

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

.KEY MESSAGES...
Issued at 205 PM AST Fri Jan 9 2026

* Swim with caution: A moderate risk of rip currents continues
  along Atlantic-facing beaches of Puerto Rico and Culebra, as
  well as the north- and east-facing beaches of St. Croix, with
  the risk expanding to western Puerto Rico and the northern U.S.
  Virgin Islands on Sunday. Dangerous swimming conditions are
  possible at exposed beaches.

* Passing showers, localized flooding risk: A typical trade-wind
  pattern will bring passing showers to windward areas during the
  mornings and isolated to locally scattered afternoon downpours,
  mainly across south-central interior to southwestern Puerto
  Rico. Localized flooding impacts are possible, especially across
  the southwestern quadrant, though widespread flooding is not
  expected.

* cool nights, typical warmth by day: Slightly below-normal to
  seasonably cool overnight temperatures will continue across
  Puerto Rico and the U.S. Virgin Islands, while daytime highs
  remain warm but near typical values for this time of
  year.Hazardous swimming conditions are possible at exposed
  beaches.

&&

.Short Term(This evening through Sunday)...
Issued at 205 PM AST Fri Jan 9 2026

Today, winds were generally light, with local sea-breeze
circulations producing briefly moderate breezes along exposed
coastal areas. A patch of low-level moisture moved across the U.S.
Virgin Islands and into eastern Puerto Rico, bringing isolated to
scattered showers and trade-wind streamers. Radar estimates
showed up to around one-half inch of rainfall across parts of the
USVI and northeastern Puerto Rico, with no significant impacts
observed. Morning lows dropped into the upper 50s across higher
elevations and the mid-70s across the USVI, while afternoon highs
reached the lower 70s in higher terrain and the mid-80s in coastal
and urban areas.

Tonight, trade winds will increase to a moderate ENENE breeze as
a building surface high shifts eastward over the western-central
Atlantic, maintaining a steady influx of low-level moisture. This
will result in patches of clouds and fast-moving trade-wind
showers, mainly affecting the USVI, Vieques, Culebra, and northern
and eastern Puerto Rico, with brief inland spillover at times. A
departing upper-level trough will place the region under
increasing subsidence, promoting mid-level drying and limited
instability. As a result, showers will be brief and become more
isolated overnight, with no significant rainfall expected. Patchy
fog may redevelop late tonight, mainly across higher elevations
and interior valleys. Overnight lows will again fall into the mid
to lower 50s in the mountains, with milder lows across lower
elevations. Land-based hazard risks will remain low to none
tonight.

A typical trade-wind pattern will persist through Saturday and
Sunday, bringing mostly favorable weather for outdoor activities,
except for brief showers. Morning showers will favor windward
areas, with isolated and very localized afternoon showers possible
over south-central to southwestern Puerto Rico due to daytime
heating and sea-breeze convergence. The driest conditions are
expected early Sunday morning. Later Sunday, a mid-level low and
an associated surface-induced trough approaching from the
northeast will gradually increase moisture, leading to more
cloudiness and scattered showers, along with a brief easterly wind
shift before ENENE flow returns. Temperatures will be near
normal Saturday, become slightly warmer late Saturday night into
Sunday, with cooler nighttime lows returning Sunday night. Aside
from a localized, limited excessive rainfall risk, overall hazard
risks will remain low to none, though continued limited rainfall
may allow dry conditions to persist or worsen, increasing
localized drought and fire-weather concerns.


&&

.Long Term(Monday through next Thursday)...
Issued at 418 AM AST Fri Jan 9 2026

Looking ahead into early next week, a deep-layer mid-to-upper-
level trough is forecast to amplify over the Atlantic Ocean east
of the northeast Caribbean on Monday. This feature will migrate
further into the Central Atlantic by Tuesday or Wednesday. As it
moves, it will generate surface disturbances that the prevailing
trade winds will advect into Puerto Rico and the US Virgin
Islands, resulting in periods of shower activity. Simultaneously,
a mid-to-upper-level ridge will build over the Northeast
Caribbean. This feature is expected to limit the vertical
development of showers and promote subsidence aloft (sinking air)
due to the presence of a dry air mass.

Model discrepancies exist around Thursday, January 15, regarding
the strength of the ridge versus the influence of a secondary
trough. ECMWF 09/00z suggests a mid-to-upper-level ridge holding
firm over the region, maintaining suppressed convective activity.
GFS 09/00z proposes a mid-to-upper-level trough swinging by the
area, which would displace the ridge and provide more favorable
upper-level dynamics for precipitation. However, the GFS also
indicates an increase in mid-to-upper-level cloud cover, which
may inhibit widespread vertical development despite the favorable
dynamics.

Given the aforementioned weather pattern, residents and visitors
in PR and the USVI can anticipate brief periods of passing
showers, especially in the evening and early morning hours in
windward locations and in the afternoon in leeward locations
(western and interior PR).

&&

.AVIATION...
(18Z TAFS)
Issued at 205 PM AST Fri Jan 9 2026

Mainly VFR conditions are expected across all terminals. Brief
VCSH/SHRA will continue to affect the USVI terminals and TJSJ as
trade-wind showers move inland from the waters. Locally induced
SHRA over interior and southwestern Puerto Rico may cause brief
MVFR cigs at TJPS between 1620Z each day. Winds will be EENE
814 kt, becoming light and variable (36 kt) after 09/22Z, then
increasing again to a moderate breeze (1014 kt) with sea-breeze
variations after 10/13Z.&&

.MARINE...
Issued at 205 PM AST Fri Jan 9 2026

A long-period northeasterly swell across the Atlantic waters and
local Caribbean passages will continue to subside tonight. A
surface high over the western-central Atlantic, along with weak
surface troughing northeast of the region, will promote moderate
ENENE trade winds tonight, becoming more easterly during the
weekend. Marine conditions are expected to remain generally
favorable for small craft, though choppy seas may develop across
the Atlantic waters on Sunday, especially as the trades
strengthen.&&

.BEACH FORECAST...
Issued at 205 PM AST Fri Jan 9 2026

A moderate risk of rip currents remains in effect for Atlantic-
facing beaches of Puerto Rico and Culebra, as well as north- and
east-facing beaches of St. Croix, where life-threatening rip
currents are possible, particularly along exposed beaches. The
moderate rip current risk may expand to western Puerto Rico and
the northern U.S. Virgin Islands by Sunday as winds and swell
conditions evolve. Beachgoers are urged to exercise caution, stay
near lifeguarded beaches when available, and avoid entering the
water if conditions appear unsafe.

&&

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

$$

SHORT TERM...ICP
LONG TERM....MID-NIGHT CREW
AVIATION...ICP
PUBLIC...MMC

NWS SJU Office Area Forecast Discussion