828
FXCA62 TJSJ 270918
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
518 AM AST Thu Nov 27 2025

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

.KEY MESSAGES...
Issued at 518 AM AST Thu Nov 27 2025

* Happy Thanksgiving! Breezy conditions are anticipated today;
  therefore, unsecured items could blow around.

* Wind-driven seas will result in choppy and hazardous marine
  conditions for small crafts; Small Craft Advisories are in
  effect.

* Life-threatening rip currents will remain possible across most
  beaches of Puerto Rico and the U.S. Virgin Islands.

* Quick moving showers will continue over windward areas of Puerto
  Rico and the U.S. Virgin Islands today and tonight; afternoon
  showers forecast today for southwestern Puerto Rico as well.

&&

.Short Term(Today through Saturday)...
Issued at 518 AM AST Thu Nov 27 2025

Partly cloudy skies prevailed overnight. As observed over the past
few days, showery weather persisted across the local waters, with
some showers reaching northern and eastern Puerto Rico and the
vicinity of the U.S. Virgin Islands. Radar estimates indicate
between 0.15 and 0.45 inches of rainfall in these areas since
midnight. Minimum temperatures ranged from the low to mid-70s across
coastal areas and the U.S. Virgin Islands, and into the mid-60s or
slightly lower across the mountains and interior valleys of Puerto
Rico.

At the surface, a broad high-pressure system over the central
tropical Atlantic will continue to support a moderate to fresh east-
northeast wind flow through the forecast period. Aloft, lingering
influence from a shortwave trough will diminish as it moves away
this morning, allowing mid-level ridging to briefly develop across
the region. A polar trough is then forecast to move across the
western Atlantic tonight, along with its associated frontal
boundary, through the short-term period.

According to the latest guidance, precipitable water values will
fluctuate between 1.30 and 1.65 inches, which is considered below
normal to near average for this time of year. As a result, a
seasonable weather pattern will dominate the forecast, with a few
passing showers across windward areas throughout the day and
isolated to scattered afternoon showers developing across the
southwest quadrant of Puerto Rico today, Thanksgiving Day. Flood
risk remains locally limited, as localized ponding on roads and in
poorly drained areas cannot be ruled out, but in general, no
significant flooding impacts are expected. A similar pattern of
trade-wind showers will persist throughout the period, with isolated
showers overnight and in the morning across windward areas of Puerto
Rico and the vicinity of the U.S. Virgin Islands, followed by
isolated to scattered afternoon showers across western
municipalities.

Model guidance continues to show 925-mb temperatures near the 25th
percentile for November climatology, supporting slightly cooler
daytime and nighttime temperatures, with no heat-related impacts
anticipated.

&&

.Long Term(Sunday through Thursday)...
Issued at 518 AM AST Thu Nov 27 2025

Up to breezy conditions are forecast to start the long term period,
particularly Sunday to early Monday as a surface high starts the
period over the western to central Atlantic, tightening the pressure
gradient. 925 mb wind speeds are forecast at high end normal to
slightly above normal values during these days, with model guidance
suggesting a decrease towards normal values Tuesday and below normal
values Wednesday and Thursday. By Tuesday and Wednesday a low
pressure system will move out of the eastern US towards the Atlantic
promoting a looser pressure gradient and, in turn, these decreasing
wind speeds. Precipitable water (PWAT) will be at up to normal
values (1.5 to 1.8 in) during the period with patches of drier and
slightly more humid air providing some variability. Patches of
moisture and nearby troughs will promote showers, steered by mainly
northeasterly flow, reaching windward sectors of the islands at
times and promote a chance of afternoon showers mainly over interior
to SW PR, these can promote brief heavy downpours. Model guidance
suggests a trough approaching the region to end the period
increasing humidity and instability while also resulting in steering
flow veering to become more southeasterly, but uncertainty remains.
925 mb temperatures are forecast to remain at below normal to low
end normal values for this time of the year, reaching more normal
values to end the period.

&&

.AVIATION...
(06Z TAFS)
Issued at 518 AM AST Thu Nov 27 2025

VFR conditions are expected to persist over the next forecast
period. Periods of VCSH across the USVI and TJSJ today. NE winds
with gusty period up to 20 to 25kts aft 227/14Z. Wind speeds
becoming lighter aft 27/22Z, around to 10 mph, with land breeze
variation overnight. VCSH activity is anticipated, particularly
across the windward areas of Puerto Rico and the USVI sites aft
28/00Z.

&&

.MARINE...
Issued at 518 AM AST Thu Nov 27 2025

Surface highs over the central Atlantic will continue to promote
moderate to fresh easterly winds over the next few days, bringing
rough seas across the offshore waters and passages. Small Craft
Advisories are in effect through Friday morning for the offshore
Atlantic Waters and the Anegada Passage. Small Craft Advisories are
also in effect through this morning for the offshore Caribbean Waters
and the Mona Passage. Even after the SCAs expire, breezy conditions
across most waters and choppy seas up to 6 feet across the Atlantic
waters are expected to prevail through early next week.

&&

.BEACH FORECAST...
Issued at 518 AM AST Thu Nov 27 2025

There is a moderate risk of rip currents (life-threatening rip
currents are possible in the surf zone) for the northern,
eastern, southeastern and some southern exposed beaches of Puerto
Rico, as well as for Culebra, Vieques and the U.S. Virgin Islands.
By tomorrow, southeastern and southern PR is forecast to have a
low risk of rip currents. Up to a moderate risk of rip currents
will continue through early next week. Visit
weather.gov/beach/sju for location-specific information.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...None.
VI...None.
AM...Small Craft Advisory until noon AST Friday for AMZ711-723.

     Small Craft Advisory until noon AST today for AMZ733-741.

&&

$$

YZR/MRR