National Weather Service Today's Weather Impact Levels

510
FXCA62 TJSJ 081650
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
1250 PM AST Sat Nov 8 2025

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

.KEY MESSAGES...
Issued at 1158 AM AST Sat Nov 8 2025

* An easterly wave will bring numerous showers and isolated
  thunderstorms late tonight into Sunday, elevating the flooding
  risk over portions of eastern and southeastern of Puerto Rico..

* Across the U.S. Virgin Islands, an easterly wave moving across
  the eastern Caribbean late tonight into Sunday will bring an
  increase in passing showers.

* A seasonable weather pattern will prevail the upcoming
  workweek, with no significant weather threats anticipated at
  this time

* Life-threatening rip currents are likely across most shorelines
  through at least early next week.

&&

.Short Term(This afternoon through Monday)...
Issued at 1158 AM AST Sat Nov 8 2025

The most recent satellite imagery suggest that a drier air mass has
moved over Puerto Rico and the Virgin Islands, putting an end to the
morning showers that were experienced early in the day. However,
enough low level moisture, along with diurnal heating and sea breeze
convergence should result in showers along the northwest quadrant of
Puerto Rico. There is a low risk of urban and small stream flooding
in these areas, and the rain should end before or around sunset.

Tonight, an easterly wave now located over the Lesser Antilles will
once again increase the frequency of showers and isolated
thunderstorms, mostly along the local waters, the vicinity of the
Virgin Islands and eastern Puerto Rico. This pattern will stretch
into tomorrow, increasing the potential for some urban flooding,
especially along the eastern third of Puerto Rico. Winds will pick
up a little too, with speeds of 14 to 21 kts, and stronger gusts,
especially within the thunderstorms.

The wave will depart by Monday, with conditions gradually improving.
In fact, a mid to upper level ridge will dominate the synoptic
pattern by then, with a trade wind cap inversion developing around
900 mb, and precipitable water values dropping to nearly 1.0 inch.
Some showers may still move at times along the eastern portions of
the area of responsibility, and diurnal heating may trigger
additional showers along western Puerto Rico, but the risk of
flooding will decrease to low and just along western Puerto Rico.

Temperatures will be seasonably warm, or just a little above normal,
with highs in the mid and upper 80s, and lows in the mid-70s in
coastal areas, and the 60s in the mountain. Areas that remain under
cloudy skies will likely see lower values for maximum
temperatures.

&&

.Long Term(Tuesday through next Saturday)...
Issued at 355 AM AST Sat Nov 8 2025

A mid- to upper-level ridge will dominate the local weather
pattern throughout the forecast period, maintaining relatively
stable conditions across the region. At the surface, a broad high-
pressure system positioned northeast of the islands will yield an
easterly wind flow. Meanwhile, a frontal boundary is forecast to
stall north of the area toward the end of the cycle.

Under the subsidence associated with the ridge aloft, available
moisture is forecast to erode from Tuesday onward. Precipitable
water values are expected to decrease to below 1.75 inches, while
500 mb temperatures are anticipated to range between -4C and
-5C. This combination will promote a more stable and drier air
mass, limiting vertical development of showers and overall
convective activity.

As a result, a seasonal weather pattern is anticipated across Puerto
Rico and the U.S. Virgin Islands with passing showers affecting
portions of eastern Puerto Rico, Culebra, Vieques, and the U.S.
Virgin Islands during the nighttime and early morning hours,
followed by limited afternoon convection over western and interior
Puerto Rico, driven by local effects and diurnal heating.
Additionally, seasonable temperatures are expected to prevail,
with daytime highs reaching the mid-to-upper 80s in coastal areas
and lower elevations.

No significant weather threats are anticipated at this time.

&&

.AVIATION...
(18Z TAFS)
Issued at 1158 AM AST Sat Nov 8 2025

TAF sites should remain under VFR conds through the prd, with the
exception of JBQ that may have tmpry MVFR conds and low CIGs/VIS
due -TSRA psbl btwn 0818/0821z. VCTS is likely over TJSJ, TIST,
and TISX around 0913z due trpcl wave approaching the CWA. Winds
will become light from the E btwn 4 - 6 kt over JSJ, JPS, and JBQ,
with ISX and IST around 10 kt. Winds will increase btwn 12 - 16
kt and gusts up to 23 kt around 0913 - 0914z.

&&

.MARINE...
Issued at 1158 AM AST Sat Nov 8 2025

A surface high pressure across the north central Atlantic will
promote moderate easterly winds across the local waters today,
becoming moderate to locally fresh tonight through Monday. An
increase shower and thunderstorm activity is expected late tonight as
a easterly wave moves across the eastern Caribbean. Although the
northerly swell will continue to subside, a smaller secondary
northeasterly swell will continue to affect the local waters
during the weekend.

&&

.BEACH FORECAST...
Issued at 1158 AM AST Sat Nov 8 2025

The moderate risk of rip currents is expected to continue along
most beaches of Puerto Rico and the U.S. Virgin Islands through
at least Monday, becoming low along southern beaches of Puerto
Rico. Nevertheless, life- threatening rip currents are likely in
the surf zone, particularly near piers, jetties, and channels.
Beachgoers are urged to heed the advice of the flag warning system
and to always swim near a lifeguard.

&&

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

$$

SHORT TERM...ERG
LONG TERM....OMS
AVIATION...MNG

NWS SJU Office Area Forecast Discussion