279
FXCA62 TJSJ 221847
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
247 PM AST Sat Nov 22 2025

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

.KEY MESSAGES...
Issued at 247 PM AST Sat Nov 22 2025

* A few passing showers tonight into early Sunday, mainly across
  windward areas, but there is a high chance that most areas will
  stay dry. Outdoor conditions will remain favorable across both
  Puerto Rico and the U.S. Virgin Islands.

* There is a low to medium chance of patchy weather on Monday as
  pockets of moisture and instability move through. Shower coverage
  is expected to remain limited, and no significant hazards are
  anticipated for any of the islands

* A breezier pattern is expected by midweek, which will enhance
  occasional trade-wind showers and bring a moderate to high chance
  of deteriorating marine and coastal conditions.

&&

.Short Term(This evening through Monday)...
Issued at 247 PM AST Sat Nov 22 2025

Overall, weather was ideal for visitors and anyone planning
outdoor activities across Puerto Rico and the U.S. Virgin Islands
during the morning hours. Mostly clear skies and calm conditions
prevailed throughout the region at this time. Coastal temperatures
reached the mid to upper 80s, with a few very localized spots
briefly touching the low 90s. Meanwhile, temperatures across the
higher terrain remained in the 70s. Winds were generally from the
northeast at 5 to 10 mph, with isolated gusts up to around 15 mph.
Under this northeasterly flow, showers developed over the
interior to southwestern Puerto Rico and across and downwind of
the USVI, Vieques, and Culebra, towards eastern Puerto Rico.
Current satellite derived precipitable water (PWAT) values
indicate a patch of 1.2 to 1.3 inches of PWAT, below
climatological normals, steered towards the islands under
northeasterly flow. As afternoon showers gradually dissipate this
evening, passing showers will move over some coastal windward
areas tonight to early tomorrow, Sunday. Current model guidance
suggests both patches of moisture (PWAT values up to 1.5 in) and
drier air (PWAT values around an inch) moving over the region.
Generally fair weather continues to be expected with afternoon
showers under northeasterly flow at interior to southwestern
Puerto Rico and downwind (and possibly across) of the USVI,
Vieques and Culebra as suggested by high resolution models.
Northeasterly flow will gradually turn from moderate to a fresh
breeze by Monday afternoon. Patchy weather is expected on Monday
under this steering flow as pockeys of moisture move over the
islands. Brief heavy showers are still expected but with limited
coverage. 925 temperatures will continue at below normal values.
Minimum temperatures are forecast in the low to mid 70s across
coastal and urban areas, with some areas of Puerto Rico, as well
as areas of the USVI, Vieques and Culebra, in the upper 70s.
Minimum temperatures are forecast at higher elevations of Puerto
Rico are forecast in the upper 50s to low 60s.

&&

.Long Term(Tuesday through next Friday)...
Issued at 314 AM AST Sat Nov 22 2025

Model guidance indicates a likelihood of a zonal upper-level flow
across the region between Tuesday and Wednesday. There is also a
moderate chance that an upper-level trough amplifying from the
Atlantic into the northeast Caribbean will push westward or weaken
the mid-level ridge. If this occurs, low-level moisture may rise
to around 700 mb as the trade-wind inversion weakens.

Overall, confidence is moderate to high that the long-term
pattern will gradually shift toward a more advective regime. A
surface high-pressure system is likely to migrate from the western
Atlantic on Tuesday to the central Atlantic by Friday, which
should promote breezy trade winds from Tuesday onward. Under this
pattern, patches of moisture embedded in the trades have a
moderate chance of producing occasional periods of showery
weather.

Temperatures across the islands are expected to continue cooling.
Model forecasts suggest that 925-mb temperatures will be slightly
below normal, roughly at the 25th percentile compared to typical
November conditions. However, there may be periods, particularly
during peak afternoon heating, when temperatures reach near-normal
levels, around the 50th percentile.

The windward areas of Puerto Rico and the U.S. Virgin Islands
will experience pleasant temperatures, with a moderate chance of
passing showers throughout the period. There is also a slight to
moderate chance of afternoon showers each day across the interior
and western Puerto Rico, with the highest probability on Tuesday
or Wednesday. The most likely time for showers across the windward
areas of Puerto Rico and the USVI will be overnight and early
morning.

&&

.AVIATION...
(18Z TAFS)
Issued at 247 PM AST Sat Nov 22 2025

Mainly VFR conditions across the terminals. VCSH and/or -SHRA
this afternoon for TIST/TISX/TJSJ/TJPS. VCSH possible for northern
and eastern terminals overnight. NE winds up to 15 kts with
higher gusts and sea breeze variations through 22/22Z, decreasing
to light and variable after 23Z.

&&

.MARINE...
Issued at 247 PM AST Sat Nov 22 2025

High pressure over the western Atlantic and a surface trough across
the central Atlantic will maintain moderate trade winds through
the rest of the weekend. By tomorrow, Sunday, and Monday, a
surface low and its cold front will interact with the high
pressure, weakening the local pressure gradient and producing
gentle to moderate easterly winds. Another high pressure will then
build over the western Atlantic and move into the central
Atlantic from Monday through Thursday. This will tighten the
pressure gradient again, supporting moderate to fresh trade winds
and choppy seas from Tuesday into mid-week. Thus, expect confused
seas due to locally choppy conditions combined with a long-period
northeasterly swell arriving between Tuesday and Wednesday.

&&

.BEACH FORECAST...
Issued at 247 PM AST Sat Nov 22 2025

There is a moderate risk of rip currents along the north-oriented
beaches of Puerto Rico and Culebra, along with eastern beaches of
St. Croix. After around 6 PM, the moderate risk of rip currents
will be relegated to north-central to northwestern beaches of
Puerto Rico. The risk is expected to decrease to low from Sunday
to Tuesday morning for the local beaches. However, starting
Tuesday evening, the risk is forecasted to rise back to moderate
due to increasing winds and confused sea conditions.

&&

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

$$

MRR/MMC

NWS SJU Office Area Forecast Discussion