952
FXCA62 TJSJ 080755 CCA
AFDSJU
Area Forecast Discussion...CORRECTED
National Weather Service San Juan PR
355 AM AST Sat Nov 8 2025
...New SHORT TERM, LONG TERM, AVIATION, MARINE, BEACH FORECAST...
.KEY MESSAGES...
Issued at 300 AM AST Sat Nov 8 2025
* A tropical wave will bring more widespread showers and
thunderstorms on Sunday, especially across eastern Puerto Rico,
with an increased risk of urban and small-stream flooding.
Breezy conditions are also expected.
* Life-threatening rip currents are likely across most shorelines
through at least early next week.
* A seasonable weather pattern will prevail the upcoming
workweek, with no significant weather threats anticipated at
this time.
* Across the U.S. Virgin Islands, tropical wave moving across the
eastern Caribbean tonight into Sunday will bring an increase in
passing showers.
&&
.Short Term(Today through Monday)...
Issued at 300 AM AST Sat Nov 8 2025
Overnight, most of the frequent rainfall activity was observed
across the eastern and southern sections of Puerto Rico, where
rainfall accumulations ranged from 0.10 to 0.50 inches. Therefore,
over those areas, skies remained mostly cloudy, while partly cloudy
to clear skies prevailed elsewhere, particularly across western
Puerto Rico and the U.S. Virgin Islands. Temperatures ranged from
the upper 70s to low 80s along the coastal areas and from the upper
60s to low 70s across the mountainous regions.
Today, typical local effects will dominate the weather pattern. Sea
breeze convergence is expected to lead to the development of
afternoon showers and a few isolated thunderstorms over western
Puerto Rico. Elsewhere, especially across eastern Puerto Rico,
Vieques, Culebra, and the U.S. Virgin Islands, occasional passing
showers are possible during the night and early morning hours.
Temperatures are expected to reach the mid- to upper 80s across
coastal areas and the mid- to upper 70s across the higher terrain.
Winds will gradually increase from today onward as a tropical wave
approaches the region from the southeast.
As the weekend progresses, a tropical wave moving across the eastern
Caribbean will bring a gradual increase in moisture. On Sunday,
precipitable water values are expected to increase to above-normal
levels for this time of year, reaching the 75th percentile. The
latest model guidance suggests relative humidity at 500 mb will
remain near to slightly above normal through this period, further
supporting vertical development of convective activity. This will
enhance the potential for more widespread showers and isolated
thunderstorms across the area. The most active period is anticipated
Sunday afternoon. Regardless, eastern Puerto Rico is forecast to
experience the greatest rainfall activity. These showers will move
quickly with the strengthening easterly winds, but some may produce
heavy rainfall capable of causing urban and small stream flooding,
particularly in low-lying or poor drainage areas.
By Monday, lingering moisture behind the departing tropical wave
will maintain unstable weather conditions across the region.
Scattered showers and isolated thunderstorms are expected through
the day, particularly across western and interior Puerto Rico during
the afternoon. While the overall intensity of rainfall is expected
to be lower compared to Sunday, periods of moderate to locally heavy
rain could still lead to ponding of water on roadways and minor
flooding in isolated spots. Temperatures will remain near normal for
this time of year, with highs in the mid-80s along the coast and
cooler readings across higher terrain.
&&
.Long Term(Tuesday through Saturday)...
Issued at 300 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...
(06Z TAFS)
Issued at 300 AM AST Sat Nov 8 2025
All TAF sites should experience VFR conditions. However, SHRA/TSRA
may develop across W PR after 08/17Z, possibly affecting JBQ through
about 08/22z. This may result in brief periods of MVFR conditions.
ESE winds at 10-15 kts and higher gust near the heaviest rainfall
activity and typical sea breeze variations to continue. Increase in
VCSH over TISX, TIST, and TJSJ after 09/00Z as a tropical wave
continues to approach the area.
&&
.MARINE...
Issued at 300 AM AST Sat Nov 8 2025
A surface high pressure across the north-central Atlantic will
yield moderate easterly winds across the local waters during the
next several days. An increase in winds and shower activity is
expected on Sunday as a tropical wave/easterly disturbance 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 300 AM AST Sat Nov 8 2025
A moderate risk of rip currents will continue to prevail across
most of the shorelines of Puerto Rico and the U.S. Virgin Islands
through at least Monday. Therefore, life-threatening rip currents
are likely in the surf zone, particularly near piers, jetties, and
channels. Conditions are expected to improve by mid-week, next
week.
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...None.
VI...None.
AM...None.
&&
$$
SHORT TERM/AVIATION...MMC
LONG TERM/BEACH FORECAST/MARINE....OMS
NWS SJU Office Area Forecast Discussion