Caribbean - Central America Weather

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
241 AM AST Sun Apr 12 2026

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

.KEY MESSAGES...
Updated at 240 AM AST Sun Apr 12 2026

* Locally induced showers and thunderstorms are expected to
develop once again over the interior and western portions of
Puerto Rico this afternoon, where the flood threat is elevated.

* Across the US Virgin Islands, showers are expected to increase
from late tonight into Monday morning.

* There is a Flood Watch for Puerto Rico and the US Virgin
Islands, and will be in effect from 10 AM Monday through 8 AM
Wednesday.

* A High Risk of Rip Currents remains in effect for the western,
northern, and eastern coast of Puerto Rico and Culebra through
Monday afternoon.

&&

.Short Term(Today through Tuesday)...
Issued at 240 AM AST Sun Apr 12 2026

Clear to partly cloudy skies were observed overnight across the
islands. Passing showers were noted mainly across the Anegada
Passage and Caribbean waters. As of 2 AM, minimum temperatures
were from the low 60s across the higher elevations of Puerto Rico
to the mid 70s across the lower elevations of the islands. The
wind was from the east at 10 mph or less. For the rest of the
morning hours, low-level clouds with scattered showers currently
over the Leeward Islands, are expected to move across portions of
the USVI and eastern PR. This surge in moisture will combine with
daytime heating and the sea breeze convergence to trigger the
development of showers and thunderstorms along the mountain ranges
of PR during the afternoon hours. Urban and small stream flooding
is likely with this activity.

For Monday and Tuesday, the combination of an approaching front,
a developing pre-frontal trough, and a mid-to upper-level trough
will promote a moist and unstable weather pattern across the
region. Satellite derived Total Precipitable Water (TPW) imagery
indicates a deep moisture plume from the NW Atlantic and another
developing over the eastern Caribbean. Global model guidance
indicates the Precipitable Water Content (PWAT) increasing from
1.70 inches today to near 2.00 inches through Tuesday, which is
above the 75th percentile for the season. Colder than normal 500
mb temperatures of -10C and -11C are also expected in response to
the deep layer upper level trough. Winds will generally be light
from the east to southeast over land areas, as the surface trough
develops over the region. However, a northeasterly component is
expected between Monday afternoon and early Tuesday morning as the
front sinks further southward across the islands. This period is
expected to be the most active in terms of the heaviest showers.
Daily rainfall accumulations are expected to range between 1 and
3 inches with locally higher amounts. This rainfall over saturated
soils will maintain an elevated threat for urban and river
flooding as well as potential mudslides in areas of steep terrain.
Therefore, a Flood Watch is in effect for all of PR and the USVI
during this time frame.

&&

.Long Term(Wednesday through Sunday)...
Issued at 240 AM AST Sun Apr 12 2026

The wet and unsettled weather pattern may extend into the long-term
forecast. A surface high pressure is expected to build over the
Western Atlantic, gradually increasing the pressure gradient,
resulting in strengthening southeasterly to easterly winds. These
conditions will bring back breezy to locally windy conditions across
the coastal areas of the islands. Nevertheless, the influence of the
deep-layered trough and abundant moisture content across the CWA
will maintain a limited to elevated risk of flooding. From the
latest model guidance, at least through Saturday, PWAT values should
increase and remain above normal for this time of the year (between
1.6 and 1.8 inches, low chance for 2.0 inches). Additionally,
moisture content in the low and mid levels should remain high
through most of the period, with relative humidity above 60 - 70 %,
and steep lapse rates in the 850 - 700 mb levels. Due to the
proximity of the trough, mid level temperatures will likely remain
cooler than normal (around - 8 degrees Celsius), while a jet streak
in the high levels will maintain strong winds (70 - 80 kt) through
Saturday, allowing ventilation and cloud growth. Additionally, the
Galvez-Davison Index (GDI) suggests deep convection activity across
the CWA, with isolated to scattered thunderstorms in the afternoons
and the night hours. The most likely scenario, from Wednesday
through Saturday, is moderate to locally heavy showers and isolated
thunderstorms moving over windward sections of Puerto Rico and the
U.S. Virgin Islands throughout the day, with afternoon convection
over the interior into northwestern/western sections of Puerto Rico.
Due to the expected weather event in the short term, saturated soils
and above-normal river levels are very likely and may enhance
flooding potential. Hence, the limited to elevated flooding threat
remains, with a limited lightning potential. Impacts may include
urban and small stream flooding, with localized flash flood,
landslides, and rapid river rises. By Sunday into Monday, weather
conditions should gradually improve, but there are discrepancies
between global solutions for early next week as members of the GEFS
are tending to wetter conditions, while ENS members are tending to a
seasonal pattern.

&&

.AVIATION...
(06Z TAFS)
Issued at 240 AM AST Sun Apr 12 2026

Mainly VFR conditions are expected to prevail through the morning
hours across all terminals. However, passing -SHRA en route fm the
Leeward terminals may reach the USVI and eastern PR terminals.
From 16z-22z, +SHRA/TSRA are expected to develop over the
interior of PR, causing mostly VCTS across the PR terminals, with
possible tempo MVFR conds at TJBQ/TJSJ. East winds between 8-14 kt
with sea breeze variations expected aft 12/14z. An approaching
front from the NW Atlantic waters could lead to +TSRA across the
offshore Atlantic waters and Mona Passage from late tonight into
Monday morning.

&&

.MARINE...
Issued at 240 AM AST Sun Apr 12 2026

A broad surface high pressure across the central Atlantic and a
front over the western Atlantic will promote moderate trades
through the rest of the weekend. Pulses of northerly swell will
continue to move through the Atlantic waters and passages,
where small craft should continue to exercise caution for the next
several days. Between Monday through Wednesday, the combination of
the front and associated pre-frontal trough will increase showers
and thunderstorms across the local waters, creating locally
hazardous marine conditions. Small Craft Advisory conditions are
expected across the Atlantic waters due to seas building up to 7
feet through midweek.

&&

.BEACH FORECAST...
Issued at 240 AM AST Sun Apr 12 2026

A life-threatening risk of rip currents will persist through at
least Monday afternoon as a pulse of northerly swell maintains a
High Rip Current Risk across the north-facing beaches of Puerto
Rico from the northwest through the northeast, as well as Culebra,
and this risk may be extended. Across Vieques and the U.S. Virgin
Islands, a moderate risk of rip currents will continue, while a
low risk persists along the southern and more protected beaches of
Puerto Rico. Increasing winds early to midweek could expand areas
of High Rip Current Risk. Avoid the water at high-risk beaches;
rip currents are likely and can be life-threatening. Sharing is
saving.

&&

.HYDROLOGY...
Issued at 240 AM AST Sun Apr 12 2026

As a mid-to upper-level trough approaches from the northwest, the
likelihood of flooding is increasing from late tonight until at
least midweek. An elevated flooding risk is forecast through this
period. Showers and thunderstorms will increase in frequency on
Monday, but the heaviest activity is anticipated for Monday night
into Tuesday. Although a level of uncertainty is still present,
the days with the highest potential for flooding are Monday and
Tuesday. However, above normal moisture will persist through late
in the week. The likelihood of urban and small stream flooding,
isolated flash flooding, landslides and rapid river rises continues
to increase. Residents and visitors are urged to remain alert to
changing weather conditions and to avoid flooded roadways. A Flood
Watch (FFASJU) and an Hydrologic Outlook (ESFSJU) are currently
in effect to highlight this flooding potential.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
213 AM AST Mon Apr 13 2026

...New SHORT TERM, LONG TERM, AVIATION, MARINE, HYDROLOGY...

.KEY MESSAGES...
Updated at 210 AM AST Mon Apr 13 2026

* A wet and unstable weather pattern will bring widespread
showers and thunderstorms across the area, with a Flash Flood
Watch in effect from 10 AM today through Wednesday.

* An elevated to significant flooding risk is expected across
the islands; residents are urged to exercise caution, avoid
flood- prone areas, and never cross flooded roads.

* The wettest period is expected from tonight into early Tuesday
morning, when the heaviest rainfall and most persistent shower
activity are likely.

* A moderate risk of rip currents will persist across all local
beaches, creating hazardous conditions for swimmers.

* Across the U.S. Virgin Islands, an elevated to significant flooding
risk is expected from early Tuesday morning through the day as
periods of heavy rainfall impact the area.

&&

.Short Term(Today through Wednesday)...
Issued at 210 AM AST Mon Apr 13 2026

Moderate to strong showers affected the Atlantic offshore and nearshore
waters for most of the night, resulting in hazardous marine
conditions due to locally higher seas and gusty winds. Given the
prevailing conditions, several Special Marine Warnings and Marine
Weather Statements were issued throughout the night. As the night
progressed, by 2 AM, showers shifted southward into coastal areas,
affecting portions of eastern and northeastern Puerto Rico,
including municipalities near Naguabo, Fajardo, and Rio Grande.
Overnight temperatures remained in the lower 70s across coastal
areas, with even cooler conditions across the mountains.

For today, the forecast of a wetter and more unstable weather
pattern remains on track. As a result, a Flash Flood Watch will be
in effect from 10 AM today through Wednesday across the entire
area. At upper levels, a deep trough with its axis just over
Hispaniola places the islands under a divergent region, favoring
vertical development and widespread thunderstorm activity. This
upper-level feature will allow colder temperatures at 500 mb,
ranging between -9°C and -10°C, which are around two standard
deviations below climatological normals. At the surface, a frontal
boundary and the associated pre-frontal trough will reach the
local area. Winds will shift to a northerly component from this
afternoon into early Tuesday as the frontal boundary moves
southward across the region. Additionally, abundant deep moisture
will be in place, with relative humidity values from 850 mb up to
500 mb near the 75th percentile. All of these factors provide a
well-defined setup for a very convective day. Model guidance
suggests an increase in showers during the morning hours, with
activity expanding and intensifying through the afternoon.
According to the highest-resolution models, a very active weather
day is expected, with the strongest convection developing across
the interior and then moving into northwestern and interior Puerto
Rico. By late afternoon into the evening, showers will affect
northeastern areas, extending into Culebra, Vieques, and the U.S.
Virgin Islands. An important factor for today will be the surface
wind pattern, as slow-moving showers will favor higher rainfall
accumulations in addition to the widespread shower activity. As a
result, an elevated to significant flooding threat is expected
across the entire forecast area today. Residents are advised to
avoid rivers and not to cross flooded roads or low-lying areas.

On Tuesday in the early morning hours into Wednesday, conditions
will remain on the unstable side, as the upper-level trough
continues to deepen, leaving a cut-off low just over the area.
This feature will be reflected through the column, resulting in a
low at 500 mb and an induced surface trough extending from around
1000 mb up to 700 mb. The presence of colder temperatures aloft
and the slow movement of this feature will continue to support
enhanced instability and prolonged convective activity across the
region. Given the expected conditions deteriorate weather
conditions are forecast across the islands. Given the expected
rainfall accumulations and the already saturated soils, this
pattern will maintain an elevated to significant risk of urban and
river flooding, as well as potential mudslides in areas of steep
terrain. Again, a Flood Watch is in effect from 10 AM this morning
through 8 AM Wednesday for all of Puerto Rico and the U.S. Virgin
Islands. Residents and visitors should continue to monitor the
latest weather information.

&&

.Long Term(Thursday through Monday)...
Issued at 210 AM AST Mon Apr 13 2026

No major changes were made to the long-term forecast, as the wet and
unsettled weather pattern is likely to persist into the weekend,
gradually improving by the first part of the next workweek. A
surface high pressure is expected to build over the Western
extending into the Central Atlantic, promoting SE-E winds through
Sunday. As a surface trough over the Hispaniola weakens, the
pressure gradient will likely increase, with winds gradually
strengthening throughout the period, resulting in breezy to windy
conditions across the coastal areas of the islands. In the mid to
upper levels, the deep-layered trough may linger and deepen into the
tropics, with our CWA under the favorable side for convection. From
the latest model guidance, moisture content will remain higher for
this time of the year, with PWAT values likely between 1.8 and 2.0
inches low chance of higher values. Additionally, the low to mid-
level moisture content should remain higher than normal, with model
soundings suggesting skinny profiles, particularly on Friday and
Saturday. In terms of convection, the influence of the trough will
maintain slightly cooler than normal mid-level temperatures (500 mb
temperatures around -8 degrees Celsius), a jet streak with 250 mb
winds between 60 and 80 knots, and divergence aloft, triggering
upper-level dynamics. Under these conditions, forced vertical motion
will result in cloud growth and ventilation, favorable for deep
convection. Additionally, the Galvez-Davison Index (GDI) continues
to suggest the potential for isolated to scattered thunderstorms
across the CWA, particularly in the afternoons over interior into
north/northwestern Puerto Rico and in the night across regional
waters, eastern Puerto Rico, and the U.S. Virgin Islands. As
mentioned in the previous discussion, the weather event in the short-
term forecast may result in saturated soils and higher-than-normal
river levels. A factor that may slightly inhibit deeper convection
is the winds, which may lead to more progressive showers instead of
stationary ones. Nevertheless, with the expected weather forecast
through Sunday, showers and thunderstorms over the CWA will increase
the flooding and lightning potential. Rainfall accumulations will
likely result in urban and small stream flooding, including
localized flash floods, including landslides, and rapid river rises.
Additionally, thunderstorms may result in gusty winds, reduced
visibility, and lightning. Residents and visitors of the islands are
encouraged to keep monitoring conditions and the next issuance of
the long-term forecast. By Monday, as another surface high pressure
builds over the western Atlantic and wind shifts from the NE, the
weather pattern should gradually improve with a drier air mass
filtering into the region.

&&

.AVIATION...
(06Z TAFS)
Issued at 210 AM AST Mon Apr 13 2026

MVFR to IFR conditions are expected across all TAF sites today due
to an increase in SHRA and TSRA activity. Periods of reduced VIS
and lowering CIGs are anticipated, with tempo IFR conditions
possible in heavier showers and thunderstorms. Mountain
obscurations will persist, especially across interior and western
sections. Winds will remain VRB through 13/15Z, then increase to
around 10 KT from the E-SE as the surface trough lifts north of
the area. Thereafter, winds will become light and variable again,
before gradually shifting to the NE around 14/03Z.

&&

.MARINE...
Issued at 210 AM AST Mon Apr 13 2026

Moderate easterly trades will persist through the period
as high pressure remains over the central Atlantic, with periods of
locally fresh winds. Combined with ongoing northerly swell, this
will maintain choppy conditions across the Atlantic waters and
passages. Increasing showers and thunderstorms early next week will
lead to locally hazardous marine conditions, including gusty winds
and reduced visibility, though impacts will be brief and variable.
By midweek, a combination of stronger winds and building swell may
result in hazardous conditions for small craft, particularly across
the Atlantic waters.

&&

.BEACH FORECAST...
Issued at 210 AM AST Mon Apr 13 2026

Rip current conditions have improved as wave
energy has decreased, no longer supporting a High Rip Current Risk.
However, a moderate risk of rip currents is in place for most north-
and east-facing beaches of Puerto Rico, including Vieques and
Culebra, as well as the U.S. Virgin Islands, meaning rip currents
are still possible and can be life-threatening. A low risk will
likely persist across western Puerto Rico, from Anasco and
Mayaguez southward and east along the Caribbean coast through
southeastern Puerto Rico, including Patillas, Maunabo, and
Yabucoa. Increasing winds early to midweek could lead to a return
of more hazardous marine and coastal conditions. Exercise caution
at the beach, especially along exposed coasts. Sharing is saving.

&&

.HYDROLOGY...
Issued at 210 AM AST Mon Apr 13 2026

As a mid-to upper-level trough approaches from the northwest, the
likelihood of flooding is expected until at least midweek. An
elevated flooding risk is forecast through this period. The
heaviest activity is anticipated for this evening into early
morning hours on Tuesday. Although a level of uncertainty is
still present, the days with the highest potential for flooding
are today and Tuesday. However, above normal moisture will
persist through late in the week. The likelihood of urban and
small stream flooding, isolated flash flooding, landslides and
rapid river rises continues to increase. Residents and visitors
are urged to remain alert to changing weather conditions and to
avoid flooded roadways. A Flood Watch (FFASJU) and an Hydrologic
Outlook (ESFSJU) are currently in effect to highlight this
flooding potential.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
232 AM AST Tue Apr 14 2026

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

.KEY MESSAGES...
Updated at 232 AM AST Tue Apr 14 2026

* Deteriorating weather conditions are expected to continue
through the rest of the week as an unsettled pattern promotes periods
of showers and thunderstorms across the region. Therefore, a
Flash Flood Watch remains in effect until Wednesday afternoon
for all of Puerto Rico.

* A moderate risk of rip currents will persist across local
beaches over the next several days.

* Seas are forecast to
gradually increase during the latter part of the week,
resulting in building wave heights and more hazardous marine
conditions for small craft, particularly across the offshore
Atlantic waters and passages.

* Variable and unstable weather conditions will prevail across
the U.S. Virgin Islands, driven by increasing atmospheric
instability and shifting wind patterns, which will support the
development of scattered to numerous showers and isolated
thunderstorms.

&&

.Short Term(Today through Thursday)...
Issued at 232 AM AST Tue Apr 14 2026

Overnight conditions were mostly cloudy to overcast across the
entire forecast area, with skies remaining largely covered through
the night. Shower activity over land was limited, with only a few
brief and isolated showers observed; however, more persistent
shower activity prevailed across the Caribbean and Atlantic
waters, occasionally moving near the coastal areas. These cloudier
conditions helped keep temperatures relatively mild along the
coasts, generally in the mid-70s, while cooler temperatures were
observed across the higher elevations due to elevation and cloud
cover. Overall, it was a calm but cloudy night with most of the
rainfall remaining offshore.

A mid-level cut-off low will remain positioned north of the
region today, promoting a strong upper-level jet streak of over 90
knots across the local area and supporting enhanced divergence
aloft, which will favor convective development. At 500 mb, a low
will induce a southwesterly flow around 25 knots, while at the
surface, an induced trough will promote variable to east-
southeasterly winds across eastern Puerto Rico and surrounding
waters, introducing some uncertainty in the focus of showers
throughout the day. Moisture will remain abundant, with
precipitable water values around the 75th percentile, well above
climatological normals, while mid-level relative humidity values
between 750–500 mb will exceed two standard deviations above
normal early in the day before gradually decreasing. Cold
temperatures aloft, ranging between -9 to -10°C at 500 mb, will
enhance instability and support the development of isolated to
scattered thunderstorms embedded within the broader shower
activity. Based on the latest analysis and model guidance, shower
activity is expected to start around mid to late morning and then
become more widespread across the interior and western sections of
Puerto Rico during the afternoon hours, with some showers
becoming locally heavy and resulting in urban and small stream
flooding. Therefore, a Flood Watch remains in effect for today,
with an elevated to significant flooding risk across portions of
the islands, although some uncertainty persists regarding the
exact placement and movement of the heaviest rainfall due to the
variable low-level wind flow associated with the surface trough.

For Wednesday, surface conditions will evolve as winds within the
0–3 km layer remain from the southeast while a surface
perturbation moves across the forecast area. According to model
guidance, the induced surface trough is expected to move east of
the CWA earlier in the day; however, the GFS places a more
defined low center just northwest of the area, and these
discrepancies may introduce some uncertainty in the overall
conditions. Nonetheless, sufficient deep moisture, with
precipitable water values near 1.8 inches, above-normal relative
humidity between 850–700 mb, and slightly colder temperatures at
500 mb will support a convective pattern with better-organized
convection, especially during the afternoon as cloudiness
interacts with local effects. Given these conditions, an elevated
flooding risk is expected, particularly across northwestern
sections of the islands, including the San Juan metro area, due to
the prevailing wind direction as the induced surface trough moves
across the region.

For Thursday, conditions become slightly more interesting at 250
mb as the previous cut-off low shifts eastward out of the area,
while a deep-layered trough continues to deepen with its axis
positioned over Hispaniola, leaving Puerto Rico and the U.S.
Virgin Islands under its influence. As a result, a more unstable
and dynamic weather pattern is expected, with abundant moisture
and increasing instability combining with favorable upper-level
support to promote the development of scattered to numerous
showers and thunderstorms across the region. Activity will likely
begin by late morning and become more widespread through the
afternoon, especially across interior and western Puerto Rico,
where locally heavy rainfall is expected, supporting efficient
rainfall processes and some storm organization, which will
increase the risk of urban and small stream flooding along with
isolated gusty winds.

&&

.Long Term(Friday through Tuesday)...
Issued at 232 AM AST Tue Apr 14 2026

An unsettled weather pattern is expected Friday through the weekend
into early next week as a short wave trough sinks into the
Caribbean. At the surface, high pressure over the western to central
Atlantic will promote moderate to fresh ESE to easterly winds Friday
and Saturday, becoming easterly Sunday and slightly ENE by Monday.
The pressure gradient will remain uneven, with stronger winds across
eastern areas and weaker flow farther west, supporting faster moving
showers in the east and slower storm motion in the west. Moisture
will increase Friday into the weekend, with PWAT values above normal
and at times exceeding climatological maxima, before slightly drier
air filters in late Sunday into Monday. Aloft, a jet streak will
lift over the area by Monday, while mid level temperatures remain
modestly cool. This pattern will support periods of convection and
isolated to locally scattered thunderstorm development across the
region. Confidence is medium, as details depend on the timing and
placement of the trough and deeper moisture.

Flooding will be the primary hazard, followed by lightning and
breezy conditions. Showers and isolated to locally scattered
thunderstorms are expected daily, generally favoring eastern Puerto
Rico and the U.S. Virgin Islands overnight into the morning, then
shifting westward each afternoon based on the latest model guidance.
The greatest risk will focus over northwestern Puerto Rico Friday
and Saturday, western Puerto Rico on Sunday, and southwestern Puerto
Rico by Monday. Faster storm motion over eastern areas may limit
rainfall totals, but slower moving convection in western sectors
could enhance flooding impacts. Breezy conditions will persist due
to the general wind flow and may be locally enhanced by thunderstorm
downdrafts. Soils may remain saturated, which could further increase
the risk of flooding, landslides, and rapid river rises. This
pattern will likely disrupt outdoor plans at times. Conditions
should gradually improve late Sunday into Monday, though some
uncertainty remains.

&&

.AVIATION...
(06Z TAFS)
Issued at 232 AM AST Tue Apr 14 2026

Mainly VFR conditions are expected across the local terminals
early in the period, deteriorating to MVFR at times due to
increasing SHRA and isolated TSRA, particularly across TJSJ, TJBQ,
and TJPS between 14/17Z and 14/23Z. Periods of lower ceilings and
reduced visibility are likely with the heaviest activity. Winds
will remain light and variable through around 14/15Z, then
increase from the E-SE at around 10 knots, with higher gusts
possible near showers and thunderstorms.

&&

.MARINE...
Issued at 232 AM AST Tue Apr 14 2026

A broad surface high pressure across the central Atlantic and a
frontal boundary over the western Atlantic will promote light to
moderate trades through the rest of the weekend. Pulses of northerly
swell will continue to move through the Atlantic waters and
passages, where small craft should continue to exercise caution over
the next several days. The combination of the front and associated
pre-frontal trough will increase showers and thunderstorms across
the local waters, creating locally hazardous marine conditions
through at least mid-week.

&&

.BEACH FORECAST...
Issued at 232 AM AST Tue Apr 14 2026

A moderate risk of rip currents will continue for most north-and
east-facing beaches of Puerto Rico, including Vieques and Culebra,
and the U.S. Virgin Islands, where rip currents are possible and can
be life-threatening. A low risk will likely persist across western
and southern Puerto Rico. Increasing winds early to midweek could
lead to a return of more hazardous marine and coastal conditions.
Residents and visitors are encourage to exercise caution at the
beach, especially along the exposed coasts.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
329 AM AST Wed Apr 15 2026

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

.KEY MESSAGES...
Updated at 327 AM AST Wed Apr 15 2026

* A high risk of rip currents will persist along the northern coast
of Puerto Rico due to ongoing northerly swell activity,
resulting in hazardous marine and coastal conditions.

* Variable weather conditions are expected today, characterized
by periods of sunshine and passing morning showers, followed by
the development of afternoon convection across portions of the
islands driven by local and diurnal effects.

* Increasing instability from Thursday into Friday, associated
with an amplifying upper-level trough and enhanced moisture
availability, will promote a more active weather pattern with widespread
afternoon convective development across Puerto Rico.

* Southeasterly low-level winds will promote slightly above-
normal temperatures, particularly across coastal and urban
areas.

&&

.Short Term(Today through Friday)...
Issued at 327 AM AST Wed Apr 15 2026

A relatively tranquil weather pattern prevailed during the
overnight hours, with mostly clear skies as earlier upper-level
cloudiness and showers shifted eastward and remained over the
surrounding waters or moved out of the forecast area. As a result,
the islands experienced clear to partly cloudy conditions. Some
showers and isolated thunderstorms lingered across the
southeastern quadrant of the CWA, mainly affecting the Caribbean
waters, with the strongest activity observed around midnight.
Overnight temperatures ranged from the low to mid 70s across
coastal areas, with slightly cooler and more refreshing conditions
across the higher elevations. Winds remained light and variable
at around 5 mph or less.

An unstable and moist weather pattern is expected today across
Puerto Rico and the U.S. Virgin Islands. Atmospheric conditions
will support the development of showers and a few thunderstorms,
aided by abundant low-level moisture and the presence of a surface
trough across the region. In addition, a cut-off low aloft is
enhancing upper-level westerly winds (zonal flow), which may help
some storms become more organized and produce locally strong wind
gusts. At the low to mid levels (1000–700 mb), winds will range
from the southeast to the south due to the surface trough, with
its axis over Hispaniola, and a mid-level low positioned just west
of the forecast area. This wind pattern is favorable for the
development of showers across northeastern Puerto Rico, extending
into north-central areas. Given the mostly clear conditions early
in the day, local and diurnal effects are expected to develop
early, potentially leading to convection by mid-morning across
northeastern Puerto Rico, including areas near El Yunque. Showers
will mainly affect northeastern areas during the morning,
followed by activity developing over the northwestern portions and
drifting into northwestern to north-central areas, as suggested
by high-resolution models. Therefore, there is a moderate to high
confidence that the bulk of the showers will be between 12 PM to 6
PM across northwestern sections, where the heaviest showers can
result in flooding problems in urban areas especially.

For late tonight into Thursday, conditions will become slightly
more favorable for instability as an upper-level trough amplifies
just west of the region, placing the divergent side of the system
over much of the eastern portion of the CWA. This setup will
enhance upper-level diffluence and support increased upward
motion, leading to a more favorable environment for convective
development. This pattern is expected to persist through the rest
of the period, as another cut-off low establishes over Hispaniola
and stalls, maintaining a diffluent pattern across the area.
Considering this overall setup, a wetter pattern is likely from
Thursday into Friday. Global model guidance and high-resolution
models suggest active afternoons driven by local and diurnal
effects, supported by limited early cloud cover. For Thursday, an
increase in low-level winds is forecast, as indicated by 925 mb
wind speeds, resulting in faster-moving showers that may limit
rainfall accumulations. Additionally, precipitable water values
are expected to remain around the 75th percentile on both days,
supporting periods of rainfall.

&&

.Long Term(Saturday through Wednesday)...
Issued at 327 AM AST Wed Apr 15 2026

Variable conditions may persist through the weekend, with a gradual
improvement over the first part of the next workweek. Wind pattern
will mostly be dominated by a surface high pressure lingering over
the Central Atlantic, promoting winds from the E-SE. Another feature
that may influence the weather pattern in the deep-layered trough
that, according to the latest model guidance, is expected to linger
over Hispaniola. From the deterministic guidance of the GFS and
ECMWF, it seems that Saturday and Sunday will most likely be the
wettest days of the period, with PWAT values lingering between 1.8
and 2.0 inches, wet for this time of the year. Additionally, low to
mid level moisture content will remain high (above 60%), while model
sounding suggests skinny profiles. Conditions look favorable for
convection, as the influence of the trough will maintain slightly
cooler than normal mid level temperatures (around -8 degrees
Celsius) and a nearby jet with strong winds aloft (around 60 knots),
allowing cloud growth and ventilation. With the favorable side of
the trough over the CWA, divergence aloft will also increase the
chance of deeper convection, particularly over western Puerto Rico
and the U.S. Virgin Islands. Hence, for the U.S. Virgin Islands,
showers and isolated thunderstorms will likely move occasionally
throughout the day, while interior and western Puerto Rico can
expect showers and thunderstorms in the afternoon that may persist
into the evening. Due to previous rainfall activity, soil
saturation, and high river levels, the potential for flooding may
increase. Hence, the flooding threat will remain limited to elevated
for the aforementioned areas. Besides flooding, expect gusty winds
and lightning across these areas. For the rest of the areas, passing
showers may move from time to time, though a significant flooding
threat is not expected. Weather conditions will gradually improve
Monday onwards, as moisture content may decrease and the subsident
side of the trough moves over the CWA. Nevertheless, there’s
uncertainty between global solutions as GFS continues with a wet
pattern (above normal PWAT) while the ECMWF on the side is moving
toward a more seasonal to drier pattern. From the latest grand
ensemble, there’s variability between them (PWAT difference of half
an inch), particularly in the mid to high level moisture content. At
the moment, expect a seasonal weather pattern, with isolated showers
moving over windward sections in the morning hours, with afternoon
convection over interior and western Puerto Rico. Due to the
uncertainty, the flood threat will remain limited.

&&

.AVIATION...
(06Z TAFS)
Issued at 327 AM AST Wed Apr 15 2026

SHRA with VCTS will persist near TISX, while VFR conditions
prevail across the remaining TAF sites during the morning hours.
Winds will remain light and variable at less than 5 kt, increasing
around 15/15Z from the S-SE at 10–15 kt. SHRA and isolated TSRA
are expected to impact TJBQ and TJSJ from 15/18Z onward, resulting
in reduced CIGS and VIS, with ceilings lowering to FL020–FL050.

&&

.MARINE...
Issued at 327 AM AST Wed Apr 15 2026

A surface high pressure system over the eastern to central Atlantic,
interacting with a stationary frontal boundary north of the region,
will promote light to gentle winds tonight. Pulses of northerly
swell spreading across the Atlantic waters will continue to maintain
seas up to 6 feet across exposed areas, where small craft should
exercise caution over the next several days. Showers and strong
thunderstorms will continue across the local waters due to the
presence of a frontal system and a trough, creating locally
hazardous marine conditions through this afternoon. Winds are
expected to become gentle to moderate from the east to east-
southeast today through the weekend.

&&

.BEACH FORECAST...
Issued at 327 AM AST Wed Apr 15 2026

A High Rip Current Risk is in effect for the northern exposed
beaches of Puerto Rico and Culebra through this afternoon due to the
arrival of pulses of a weak northerly swell. Beachgoers are urged to
heed the advice of lifeguards, as well as beach patrol flags and
posted signs. Elsewhere, a low to moderate risk of rip currents will
persists. Increasing winds from midweek onward could lead to a
moderate risk of rip currents persisting along north-exposed beaches
through at least next Saturday.