Caribbean - Central America Weather

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
316 AM AST Sun Jan 25 2026

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

.KEY MESSAGES...
Issued at 305 AM AST Sun Jan 25 2026

* Hazardous conditions for small boat continue today along the
offshore Atlantic waters, but conditions will gradually improve
by tonight. Inexperienced mariners should avoid navigating these
waters.

* Across the U.S. Virgin Islands, lots of sunshine is expected
through the first half of the day, with a few showers reaching
the islands later in the afternoon and evening hours.

* Partly cloudy skies will persist across Puerto Rico today, with
showers developing in the interior and west this afternoon. No
flooding risk is anticipated with these showers.

&&

.Short Term(Today through Tuesday)...
Issued at 305 AM AST Sun Jan 25 2026

During the overnight hours, clear to partly cloudy skies prevailed
across much of Puerto Rico and the U.S. Virgin Islands, with passing
showers brushing coastal areas at times. However, shower activity
gradually decreased toward the early morning hours as a dry slot
approached from the east. GOES-19 PWAT imagery indicated values
dropping below one inch within this drier air mass, supporting a
notable reduction in rainfall coverage and intensity. As a result,
mostly fair weather conditions with little to no rainfall are
expected during the morning hours today.

A few showers may still develop during the afternoon hours,
primarily over interior and western portions of Puerto Rico due to
local effects and diurnal heating, but activity is expected to be
less frequent and less widespread than observed on yesterday.

For the remainder of the short-term period, a mid-level ridge is
forecast to build and settle over the northeastern Caribbean. This
pattern will promote mid-level drying and increased subsidence,
along with warming near the 500 mb level, resulting in reduced
instability aloft. Precipitable water values will continue to
fluctuate as patches of shallow moisture move across the islands
from time to time. Consequently, mostly fair weather conditions are
expected to prevail, with passing showers affecting windward coastal
areas during the nighttime and morning hours, and some afternoon
shower development over interior and western sections of Puerto Rico
each day. The frequency and coverage of these showers will largely
depend on the timing and extent of these moisture patches.

Breezy easterly winds will continue today, particularly across
coastal and exposed areas. However, winds are expected to gradually
diminish through the end of the short-term forecast period as the
surface high pressure over the central Atlantic shifts eastward and
a col approaches from the northwest, weakening the pressure gradient
across the northeastern Caribbean.

&&

.Long Term(Wednesday through Sunday)...
Issued at 305 AM AST Sun Jan 25 2026

The mid to upper level ridge will hold on Wednesday. At the low
levels, limited moisture in anticipated, so fair weather should
persist until then. Then, there are some changes in store Thursday
onward. First, a polar trough will weaken the pressure gradient,
causing winds to become lighter. Surface steering flow will fall to
nearly 9 knots on Thursday to about 2-6 knots on Friday. The polar
trough will escort a cold front near Hispaniola and Cuba, with winds
shifting from the south from the surface into the mid levels of the
atmosphere. As a result, warmer than normal temperatures are
anticipated. Also, the shift in winds will bring a slot of dry air
on Thursday, followed by increasing moisture Friday onward. With
light winds on Friday, showers are expected to form in the
Cordillera Central, where urban and small stream flooding could
occur. Then, on the weekend, additional moisture will approach
from the south, and also from the north (associated with the cold
front). Increasing shower frequency is expected for the Caribbean
and Atlantic waters. The proximity of the cold front will cause
winds to weaken again on Sunday, with speeds of 1 to 5 knots and
variable wind speeds. The global models also show the front
crossing late on Sunday, which could cause another increase in
showers and thunderstorms across the area.

.AVIATION...
(06Z TAFS)
Issued at 305 AM AST Sun Jan 25 2026

VFR conds will prevail across all terminals thru the fcst period.
Passing SHRA may affect mainly windward terminals at times, but no
sig VIS or CIGs restrictions are expected. Winds will remain from
the E–ENE at 10–16 kt with higher gusts possible, especially aft
25/14Z.&&

.MARINE...
Issued at 305 AM AST Sun Jan 25 2026

A building high pressure centered over the western Atlantic, north of
the islands, will bring moderate to fresh tonight through Monday.
Winds will remain moderate toward the middle portion of the week as
the high rolls into the central and eastern Atlantic. Showers will
be less frequent today, moving across the Atlantic and Caribbean
waters.

&&

.BEACH FORECAST...
Issued at 305 AM AST Sun Jan 25 2026

Breezy conditions will maintain a moderate rip current risk for
the north and east facing beaches of Puerto Rico, as well as for
Vieques, Culebra and all the beaches across the Virgin Islands.
Similar conditions are expected to persist through the upcoming
days, with only the west, south, and southwest of Puerto Rico with
a low risk of rip currents.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
417 AM AST Mon Jan 26 2026

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

.KEY MESSAGES...
Issued at 414 AM AST Mon Jan 26 2026

* Wind-driven seas will continue to produce choppy marine conditions
today, gradually subsiding as winds decrease during the week.

* Hazardous seas and coastal conditions may return next weekend as a
long-period northerly swell and an approaching frontal boundary
affect the regional waters.

* Passing showers will affect the islands at times, with a low risk
of minor flooding, mainly in urban and poor drainage areas.

* Shower activity is expected to increase by late next weekend as
a weakening frontal boundary and increasing moisture approach
the region, with a potential for locally heavy rainfall.

&&

.Short Term(Today through Wednesday)...
Issued at 414 AM AST Mon Jan 26 2026

Showers were observed during the night hours around the Caribbean
and Atlantic waters, with some showers reaching St. John and St.
Thomas and eastern Puerto Rico. However, Multi-radar Multi-sensor
rainfall accumulation only showed amounts below ten hundredth of an
inch. Skies were variably cloudy, and temperatures cooled down to
the low 70s in coastal areas and the mid-60s in the mountains.

Surface high pressure continue to roll toward the eastern Atlantic,
maintain the gradient relatively strong today. Winds will be coming
out of the east southeast at 15 to 20 knots with stronger gusts. As
the high moves farther away, winds will relax a little, at nearly 10
knots. Today, satellite derived precipitable water imagery shows a
little area of dry air reaching the Virgin Islands and eastern
Puerto Rico in the morning hours. However, an area of enhanced
moisture will filter in just in time for local effects to kick in.
With the breezy winds, streamers are favored across the Cordillera
Central, from El Yunque into the San Juan metro area, westward of
the Virgin Islands, and across western Puerto Rico. Shower activity
could lead to ponding of water on roadways and low-lying areas.
Isolated urban and small stream flooding cannot be ruled out.
Tomorrow, the trade winds will bring another patch of moisture into
the islands, so expect similar weather conditions. The risk of
flooding will be low, and focused on western Puerto Rico. On
Wednesday, precipitable water values fall well below normal. With
this drier than normal air, mostly fair weather is anticipated,
although a few isolated showers cannot be ruled out.

Southeast winds will cause temperatures to climb up. At this time,
925 mb temperatures will be nearly one standard deviation above
normal. Highs will be around 87 to 89 degrees in coastal areas, with
lows still comfortable, around the 70s in coastal areas and in the
60s in the mountains.

&&

.Long Term(Thursday through Monday)...
Issued at 414 AM AST Mon Jan 26 2026

The overall synoptic pattern will remain largely unchanged through
the early part of the period. Ridging aloft will persist across the
region through at least Friday, while limited low-level moisture
supports generally fair weather conditions. As a result, stable
conditions are expected to continue, with only brief passing showers
mainly driven by patches of moisture streaming across the area from
time to time.

Changes in the pattern become more noticeable toward the latter part
of the weekend. Global model guidance continues to suggest
increasing moisture associated with a weakening frontal boundary,
although the timing of this feature has been pushed back. Moisture
advection from the south ahead of the approaching boundary remains a
consistent signal among global models, particularly by late Sunday.
This increase in moisture, combined with modest instability, will
support a higher frequency of showers, especially across the
Caribbean waters and western sections of Puerto Rico. The Galvez-
Davison Index indicates elevated values near the frontal boundary,
suggesting an increased potential for heavy rainfall-producing
thunderstorms approaching from the west as the boundary nears the
islands.

Potential impacts by the end of the period include periods of
locally heavy rainfall, isolated thunderstorms, and ponding of water
in poor drainage areas, with a limited risk of urban and small-
stream flooding. Gusty wind conditions may also accompany convective
activity, particularly near thunderstorms.

Southeasterly to southerly low-level flow ahead of the boundary will
develop late by the end of the week into the weekend, promoting
above normal temperatures across the islands.

&&

.AVIATION...
(06Z TAFS)
Issued at 414 AM AST Mon Jan 26 2026

Mainly VFR conditions expected to prevail. SHRA will move across the
local waters all day today. After 17Z, SHRA expected to increase
along the Cordillera Central, potentially reaching TJSJ and TJBQ at
times. Periods of reduced VIS and low ceilings can be expected. It
stays breezy today, with winds from SFC to FL050 at 17-21 kts, with
stronger gusts.

&&

.MARINE...
Issued at 414 AM AST Mon Jan 26 2026

A building high-pressure system centered over the western Atlantic
and gradually moving eastward will continue to promote moderate to
locally fresh easterly winds through at least today. Winds are
expected to gradually ease from midweek into late week as the high
shifts farther east into the central Atlantic. Looking ahead to next
weekend, a long-period northerly swell is expected to reach the
regional Atlantic waters, which may result in hazardous marine
conditions, particularly across the offshore Atlantic waters.

&&

.BEACH FORECAST...
Issued at 414 AM AST Mon Jan 26 2026

Breezy conditions continue across the regional waters, maintaining
choppy seas and a moderate risk of rip currents along most exposed
beaches. The highest risk remains along the north- and east-facing
beaches of Puerto Rico, including Culebra, as well as the U.S.
Virgin Islands, where lingering wind-driven seas continue to enhance
rip current formation.

Winds are expected to gradually subside through the week; however,
periodic pulses of weak northerly swells will move through the
region, sustaining moderate rip current risks along northern exposed
beaches of the islands. As a result, life-threatening rip currents
will remain possible, particularly at beaches exposed to the
Atlantic.