668
FXCA62 TJSJ 281734
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
134 PM AST Fri Nov 28 2025

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

.KEY MESSAGES...
Issued at 1148 AM AST Fri Nov 28 2025

* Occasional showers and isolated thunderstorms are expected this
  afternoon and evening, posing a limited risk of flooding across
  Puerto Rico and the U.S. Virgin Islands.

* Breezy trade winds will prevail today, becoming windy during
  the weekend into early next week.

* The north and east-facing beaches in PR and the USVI have a
  moderate risk of life-threatening rip currents throughout the
  weekend.

* Pleasant temperatures, with a mix of sunshine and clouds, will
  prevail across the USVI and PR throughout the forecast period.

&&

.Short Term(This afternoon through Sunday)...
Issued at 1148 AM AST Fri Nov 28 2025

Frequent showers embedded in the easterlies moved across the
windward locations of Puerto Rico and the U.S. Virgin Islands
throughout the morning. Ponding of water along roads and in poorly
drained areas was observed during this activity. A few
thunderstorms were noted by radar and satellite imagery. Afternoon
convection developed along the Cordillera Central and western PR,
as well as downwind from the USVI. Winds were mainly from the
east at 15 to 20 mph, but locally higher near showers and
thunderstorms. Maximum temperatures were in the mid-80s or upper
80s along the coast and in urban areas, and in the upper 70s or
low 80s in the mountains and valleys.

An upper-level trough is expected to exit the northeast Caribbean
today, allowing a mid- to upper-level ridge to likely build over
the islands later today and through the weekend. Another upper-
level trough has a moderate chance of moving across the region
from Sunday into early next week, which would increase
instability, particularly Sunday afternoon and evening.

At the surface, the interaction between a surface high pressure
system over the central Atlantic and a cold front moving east
across the western Atlantic will likely support breezy to windy
trade wind conditions through the weekend.

Given this pattern, there is a moderate (30-50%) to high (60%)
chance of occasional passing showers across the islands,
especially over the windward areas. This afternoon into the
evening, showers are expected to spread into the interior and
western Puerto Rico, with a moderate (50%) to high (60-80%) chance
of rain. There is a slight risk of flooding rains and isolated
thunderstorms across portions of the U.S. Virgin Islands and
eastern, interior, and western Puerto Rico.

Although conditions are likely to be more stable on Saturday,
tradewind showers will continue at times, with a moderate (30-50%)
chance. These showers may extend inland and into western Puerto
Rico by the afternoon, where the chance of rain is moderate
(40-50%) to high (60%).

A similar pattern is likely on Sunday, but with greater
instability, increasing the potential for flooding rains and
thunderstorms.

&&

.Long Term(Monday through next Friday)...
Issued at 542 AM AST Fri Nov 28 2025

By early next week, winds will remain somewhat breezy but will
gradually subside as a polar trough pushes and weakens the surface
high over the northeastern Atlantic, easing the pressure gradient
across the region. By Tuesday and Wednesday, expect northeasterly
winds with speeds decreasing to around 8 to 13 mph.

According to the latest precipitable water (PWAT) guidance, moisture
will vary as patches of drier and slightly more humid air move
through the area. From Monday through early Wednesday, PWAT values
will remain near normal for this time of year, ranging between
1.50 and 1.75 inches. This streaming moisture will support passing
showers, mainly steered by a northeasterly flow, affecting windward
sectors at times. Afternoon convection is also possible, especially
over interior and southwestern Puerto Rico, where brief heavy
downpours may occur.

By Wednesday afternoon, PWAT values will begin increasing, reaching
1.75 to 2.00 inches through Thursday. Model guidance indicates a
surface trough approaching the region Wednesday afternoon into
Thursday, accompanied by upper-level troughing. This will enhance
moisture and instability while causing the steering flow to veer
more easterly. As a result, this period have the highest chances
of precipitation, though the flood risk remains limited at this
time. Continue to monitor forecast updates as confidence improves
in the coming days. Winds are also expected to become breezy again
from Thursday into Friday. By the end of the period, Friday, more
stable conditions are expected as ridging builds at various levels
of the atmosphere, introducing drier air with PWAT values falling
below 1.4 inches, along with breezy easterly winds.

Temperatures at 925 mb are forecast to rise to near-average values,
supporting seasonal surface temperatures. However, no heat-related
risks are anticipated at this time.

&&

.AVIATION...
(18Z TAFS)
Issued at 1148 AM AST Fri Nov 28 2025

SHRA/ISOLD TSRA will affect PR/USVI terminals with brief MVFR/IFR in
+SHRA/TSRA, and BKN CIGS at FL020040, particularly ovr TJBQ/TJSJ
terminals. Outside convective bursts, VFR prevails. E-ESE sfc
winds 1318 kt with ocnl G2025 kt and sea-breeze variation. Winds
bcm VRB0306KT aft 28/22Z. USVI terminals may also see VCSH/VCTS
in streamer bands. Impacts mainly tempo and short-lived.

&&

.MARINE...
Issued at 1148 AM AST Fri Nov 28 2025

An upper-level trough moving across the Northeast Caribbean will
promote thunderstorm formation over local waters, especially
during the afternoon and evening hours. A surface high pressure
over the Central Atlantic, interacting with a cold front moving
eastward across the western Atlantic, will promote moderate to
fresh easterlies winds today, becoming fresh to strong trade winds
this weekend into early next week. This will result in rough to
hazardous seas across the local waters today and throughout the
weekend.

&&

.BEACH FORECAST...
Issued at 1148 AM AST Fri Nov 28 2025

The risk of encountering life-threatening rip currents remains
moderate along north- and east-facing beaches from northwestern to
eastern Puerto Rico, as well as in Vieques, Culebra, and the U.S.
Virgin Islands. This moderate risk will persist through the
forecast period, with life-threatening rip currents possible,
especially along the north and east-facing beaches of the islands.
In other areas, the risk is low; however, even in low-risk areas,
dangerous rip currents can still develop near groins, jetties,
reefs, and piers.

&&

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

&&

$$

MORNING CREW...CAM/CVB
EVENING CREW...DS/GRS