National Weather Service Today's Weather Impact Levels

899
FXCA62 TJSJ 081656
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
1256 PM AST Thu Jan 8 2026

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

.KEY MESSAGES...
Issued at 1205 PM AST Thu Jan 8 2026

* An increase in the potential for shower activity is forecast for
  this afternoon along the interior and western sections of PR.

* Life-threatening rip currents will remain through 6 PM today
  along the north and east-facing beaches of Puerto Rico as a
  persistent northeasterly swell across the local Atlantic waters
  prevails. A moderate risk will continue for north and east-
  facing beaches of the U.S. Virgin Islands after 6 PM.

* Seasonal temperatures will prevail across the islands through
  the next several days, with cooler conditions continuing in the
  higher elevations.


&&

.Short Term(This evening through Saturday)...
Issued at 1205 PM AST Thu Jan 8 2026

Clear to partly cloudy skies prevailed across the islands this
morning, with brief passing showers mainly affecting eastern and
northeastern Puerto Rico. Conditions remained seasonable, with light
northeast winds and limited moisture.

Weather conditions from this evening through Saturday will remain
governed by a weak and persistent pattern, with no major synoptic
changes anticipated. A weak surface trough lingering northeast of
the region, along with subtle troughing aloft, will continue to
promote shallow shower activity embedded within the trade wind flow.
Precipitable water values will remain near to slightly below
seasonal levels, generally around 1.2 to 1.4 inches.

For this afternoon into early evening, ensemble guidance indicates
the highest rainfall potential across interior and western to
southwestern Puerto Rico, where localized amounts near or slightly
above one inch are possible due to daytime heating and sea-breeze
convergence in combination with sufficient low-level moisture. This
evening and overnight, shower activity will gradually diminish over
western areas and transition back to brief trade wind showers
affecting eastern Puerto Rico and the U.S. Virgin Islands.  On
Friday and Saturday, a similar pattern will persist. Morning hours
will favor passing showers across windward areas, followed by
isolated to scattered afternoon showers over interior and western
Puerto Rico driven by daytime heating and local effects.

Temperatures will remain near climatological normals throughout the
period. The 925 mb temperatures support seasonable daytime highs
across coastal areas, with cooler conditions continuing across
higher elevations during the overnight and early morning hours.

Overall, the short-term period will feature generally fair and
seasonable weather, punctuated by brief passing showers and
localized afternoon convection, with the greatest rainfall potential
confined to interior and western Puerto Rico this afternoon and
again during peak heating periods through Saturday.

&&

.Long Term(Sunday through next Wednesday)...
Issued at 403 AM AST Thu Jan 8 2026

Surface high pressure over the north-central Atlantic will promote
moderate to locally fresh east-northeast winds through late Tuesday
night. From Wednesday onward, winds are expected to shift from the
east as the high pressure migrates toward the eastern Atlantic. At
the mid-to-upper levels, a ridge will build over the southwestern
Atlantic while a Tropical Upper Tropospheric Trough (TUTT) begins to
develop over the central Atlantic, northeast of the Lesser Antilles.

The latest model guidance continues to suggest precipitable water
(PWAT) values will remain near normal on Sunday before dropping
below seasonal averages by Monday (0.85 to 1.21 inches). Despite the
strength of the TUTT low to the northeast, dry air intrusion
associated with the mid-to-upper level ridge will promote stable
conditions aloft. This will inhibit shower development across Puerto
Rico and the U.S. Virgin Islands throughout the period.

Temperatures at the 925 mb level will remain near seasonal averages.
Consequently, expect maximum temperatures in the low to mid-80s
across lower elevations and in the mid to upper 70s across higher
terrain.

&&

.AVIATION...
(18Z TAFS)
Issued at 1205 PM AST Thu Jan 8 2026

Mainly VFR conditions expected across all terminals. Brief VCSH/SHRA
possible this afternoon into early evening, mainly across TJPS, with
isolated MVFR in heavier showers. Activity diminishes after sunset.
E-ENE winds 5-12 kt, locally gusty during the afternoon with sea
breeze variations, becoming lighter overnight and increasing again
aft 09/13z.


&&

.MARINE...
Issued at 1205 PM AST Thu Jan 8 2026

The long-period northeasterly swell will continue to spread
across the Atlantic waters and local Caribbean passages through
this evening. A surface high pressure over the western Atlantic,
along with weak induced surface troughs northeast of the region,
will promote moderate east to northeast trade winds through the
the rest of the week.

&&

.BEACH FORECAST...
Issued at 1205 PM AST Thu Jan 8 2026

Hazardous coastal conditions will continue across the local
beaches through at least this afternoon due to a spreading
northeasterly swell affecting the Atlantic waters. This swell will
maintain life- threatening rip current conditions along the
northwest to northeast-facing beaches of Puerto Rico, where a High
Rip Current Risk remains in effect until 6 PM AST today. Life-
threatening rip currents are possible along north and east- facing
beaches of the U.S. Virgin Islands, where a moderate rip current
risk is expected.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk until 6 PM AST this evening for PRZ001-002-
     005-008.

VI...None.
AM...None.
&&

$$

SHORT TERM/AVIATION...CVB
MARINE/BEACH/KEY...MMC

NWS SJU Office Area Forecast Discussion