Atlantic Hurricane Season 2025 Storm Names

547
FXCA62 TJSJ 230851
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
451 AM AST Sun Mar 23 2025

.SYNOPSIS...

Remnants of the old frontal boundary will provide a favorable
environment for scattered showers across eastern Puerto Rico and
near the U.S. Virgin Islands, today. For Monday and Tuesday, a
more stable and drier air mass will be present. Late Tuesday and
and Wednesday, additional frontal remnants along with a surge in
winds can result in an increase in shower activity. An unstable
weather pattern could prevail by the second part of next week with
the arrival of a mid to upper-level trough and a frontal boundary
at low-levels.

A northwesterly to northerly swell will spread across the local
waters by late morning today through early tomorrow and will
result in a High Risk of Rip Currents for the north-oriented
beaches of Puerto Rico, from Rincon to Fajardo, and for the
northern beaches of Culebra, St. Thomas and St. John.

&&

.SHORT TERM...Sunday through Tuesday...

During the overnight hours, Doppler radar indicated scattered
showers over the coastal waters near the US Virgin Islands, Culebra,
and Vieques, along with some light showers across the San Juan Metro
area and the north-central coastal plains of Puerto Rico.

Today is expected to be another active day, as remnants of the old
frontal boundary linger across the northern Caribbean, providing a
favorable environment for scattered showers across eastern Puerto
Rico and near the U.S. Virgin Islands. While a mid-level ridge
maintains a relatively stable atmosphere aloft, sufficient moisture
in the lower 3 km of the atmosphere will support continued shower
development across the region. Although vertical growth of showers
will be limited due to mid-level stability, slightly above-normal
precipitable water values and moderate trade winds may allow for
some training of showers. The affected areas in the afternoon are
likely to be downwind of El Yunque, the western interior, and
Mayaguez and its vicinity.

For Monday and Tuesday, the remnants of the front will continue to
dissipate, and increasing subsidence from the mid-level ridge will
promote a more stable and drier air mass across the islands. As a
result, shower coverage will decrease significantly, with mostly
sunny skies prevailing both days. Fresh trade winds will aid in
moisture convergence, leading to a few additional showers over the
US Virgin Islands and eastern Puerto Rico by Tuesday evening, though
these showers are expected to be less frequent and less intense
compared to Saturday`s activity.

.LONG TERM...Wednesday through Sunday...

Current model guidance suggest the approach of a patch of
moisture remnants from a past frontal boundary, with precipitable
water (PWAT) values ranging from 1.5 to 1.75 in, which are above
normal values for this time of the year. This moisture patch is
forecast to reach the local islands overnight to early morning on
Wednesday, promoting shower activity steered by east to east-
southeast flow over windward sectors of the islands. This feature
will also be accompanied by a wind surge, promoting up to breezy
condtions. However, a strong surface high will be in place over
the central Atlantic by midweek while a mid to upper level ridge
will also be present through early Thursday promoting more stable
and drier conditions aloft, with available moisture mostly
contained below 700 mb. This will all serve to limit shower
development. The general diurnal pattern (with overnight and
morning trade wind showers moving over windward sectors of the
islands and afternoon convective showers mainly over west-
northwest Puerto Rico due to diurnal heating, sea breeze
convergence and local effects) will be present during the period
but will be boosted by an increase in moisture and instability
over the region Friday and Saturday. Moisture and instability will
increase due to a mid to upper trough moving near the region
Friday into Saturday. PWAT values will also increase to at or
above 1.5 in over the islands as another frontal boundary or its
remnants move over the region. The steering flow is forecast to
back and become more northeasterly by Saturday and Sunday, causing
afternoon convection to concentrate over west to southwest PR.
Model guidance suggest a drying trend by Sunday. 925mb
temperatures will be at normal to above normal values to start the
period.

&&

.AVIATION...

(06Z TAFs)

VFR conditions are forecast to prevail across all terminals through
the forecast period. Clouds and scattered showers associated with
remnants of an old frontal boundary may affect briefly USVI
terminals and TJSJ during through 15Z. TJBQ may experience VCSH in
the afternoon associated with SHRA affecting TJMZ around 17Z-21Z.
ENE to E winds around 15-20 kt with higher gusts and sea breeze
variations thru 23z, diminishing below 10 kt overnight.

&&

.MARINE...

A surface high pressure will build across the Central Atlantic,
tightening the local pressure gradient and promoting moderate to
fresh trade winds throughout most of the week. A northwesterly to
northerly swell will start to spread across the local waters by late
morning today and will gradually dissipate by early tomorrow, Monday.
Remnants of an old frontal boundary lingers across the northern
Caribbean, promoting shower activity over the waters.

&&

.BEACH FORECAST...

A northwesterly to northerly swell will start to spread across
the local waters by late morning today and will gradually
dissipate by early tomorrow, Monday. This swell will result in a
High Risk of Rip Currents from noon AST today through at least 6
AM AST tomorrow, Monday for the north-oriented beaches of Puerto
Rico, from Rincon to Fajardo, and for the northern beaches of
Culebra, St. Thomas and St. John. Low to moderate risk elsewhere
in Puerto Rico and a moderate risk elsewhere in Culebra and the
northern USVI. There is a moderate risk of rip currents for
Vieques and St. Croix. For more information, please refer to the
latest Coastal Hazard Message (CFWSJU) and the latest Surf Zone
Forecast (SRFSJU).

If you become caught in a rip current, yell for help. Remain
calm, do not exhaust yourself and stay afloat while waiting for
help. If you have to swim out of a rip current, swim parallel to
shore and back toward the beach when possible. Do not attempt to
swim directly against a rip current as you will tire quickly.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk from noon AST today through late tonight
     for PRZ001-002-005-008-010-012.

VI...High Rip Current Risk from noon AST today through late tonight
     for VIZ001.

AM...None.
&&

$$

SHORT TERM...ERF
LONG TERM....MRR

NWS SJU Office Area Forecast Discussion