Atlantic Hurricane Season 2025 Storm Names

485
FXCA62 TJSJ 250915
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
515 AM AST Fri Apr 25 2025

.SYNOPSIS...

Moisture content will start to increase today and tonight leading
to showers across the U.S. Virgin Islands and surrounding waters,
then scattered to numerous showers with isolated thunderstorms
this afternoon across the interior of Puerto Rico. A unstable and
wetter weather pattern will prevail during the weekend into next
week. A northeasterly swell will reach the Atlantic waters
resulting in a high risk of rip currents on Sunday. Residents and
visitors are encouraged to stay informed by monitoring official
forecast updates.

&&

.SHORT TERM...Today through Sunday...

Mostly clear skies and no shower activity prevailed throughout the
overnight hours, due to a persistent dry slot over the area. Minimum
temperatures ranged from the low to mid-60s in higher elevations to
the low to mid-70s in coastal areas. These values were slightly
cooler than the previous night, due to the absence of cloud cover.
Very light winds were observed, as the locally weakened pressure
gradient caused by surface-induced troughs has persisted in the
region.

The most recent satellite-derived precipitable water product shows a
moisture gradient over the region. Well below normal moisture values
are observed along a southwest-to-northeast oriented slot over
Puerto Rico, while abundant moisture is present in the vicinity of
Saint Croix. According to the 00Z Tropical Analysis and Forecast
Branch (TAFB) surface analysis, the forecast area is situated
between two surface troughs, with their axes located to the
northwest and southeast of the region. Favorable upper-level
dynamics also persist, as a mid- to upper-level trough remains in
place. This feature contributes to cool temperatures near 500 mb and
supportive jet dynamics, with southwesterly winds around 70 knots at
250 mb providing good ventilation aloft. This overall pattern can
support the development of showers and thunderstorms. However,
limited moisture continues to be a restricting factor.

Today, however, low- to mid-level moisture is expected to gradually
increase as the area of above-normal moisture near Saint Croix moves
closer to the region. Model guidance continues to show slight
variations in the timing of this moisture`s arrival. Nevertheless,
this afternoon, the increasing moisture combined with surface
heating and local effects is expected to result in shower and
thunderstorm activity across the central interior and possibly the
north-central areas of Puerto Rico. This could lead to an elevated
flooding threat. During the evening and overnight hours, as the
broad area of above-normal moisture continues to gradually move
over the region, an increase in showers and isolated thunderstorms
is expected across the U.S. Virgin Islands, Vieques, Culebra, and
parts of eastern Puerto Rico. A limited flooding threat is
anticipated during this period.

For the remainder of the short-term forecast period, the areal
coverage of showers and thunderstorm activity is expected to
increase as favorable upper-level dynamics persist and combine with
well above normal moisture over the region. Model guidance indicates
that Sunday will likely be the most active day of the short-term
period. Continued urban and small stream flooding is anticipated
this weekend, along with the potential for landslides in areas of
steep terrain, particularly in locations that remain vulnerable due
to excessive rainfall during the past weekend.

.LONG TERM...Monday through Friday...

For the long-term period, model guidance continues to suggest a
persistently wet and unstable pattern early next week. A mid- to
upper-level trough and an associated jet streak will enhance lift
and divergence aloft, creating favorable conditions for the
development of showers and thunderstorms. Precipitable water
(PWAT) values are forecast to remain above climatological levels,
ranging from around 1.8 inches up to 2.2 inches at least through
midweek, then gradually decreasing by the latter part of the week.
Additionally, mid-level relative humidity is expected to increase
significantly, peaking at about two standard deviations above
average for this time of year.

Furthermore, based on the latest models, 500 mb temperatures will
remain around -8 to -9 degrees Celsius throughout the forecast
period, maintaining upper-level instability and supporting
continued thunderstorm development. The overall pattern suggests
showers will mainly affect our local waters and the U.S. Virgin
Islands during the overnight hours, reaching the northern and
eastern sectors of Puerto Rico in the mornings. As the days
progress, showers and potentially thunderstorms will become more
concentrated across the interior and western sectors of Puerto
Rico.

The primary concern during this period is the increased risk of
flooding, which is expected to remain elevated through at least
midweek. Current model trends indicate that the highest potential
for moderate to heavy rainfall will occur between Sunday and
Tuesday, which could lead to localized flooding, particularly in
urban, low-lying, and mountainous areas. While there is still some
uncertainty regarding the exact timing of the heaviest rainfall,
the potential for impactful weather remains significant. Residents
and visitors are encouraged to stay weather-aware and informed by
monitoring official forecast updates, as conditions may change
rapidly as uncertainty decreases in the coming days. We can expect
a gradual improvement in weather conditions toward the end of the
week, as a surface high-pressure system builds across the western
Atlantic and promotes a northeasterly wind flow that will push
drier air into the region.

&&

.AVIATION...
(06Z TAFs)

Mostly VFR conditions expected throughout the period. Vicinity
SHRA/TSRA possible at TISX through 15Z. Aft 17Z, SHRA/TSRA expected
to develop over interior Puerto Rico, potentially affecting the
vicinity of TJSJ and TJPS. Activity may result in brief reductions
in VIS and lowering of CIGs. Mountain obscuration likely across the
interior Cordillera Central. SHRA/TSRA may increase near TISX and
TIST aft 23Z. Winds light and variable early, becoming northeast at
up to 12 knots aft 14Z.

&&

.MARINE...

Light and variable winds will prevail through Saturday, then
moderate easterly winds are expected to return by Saturday night.
Overall conditions should remain favorable for small craft, but
localized hazardous marine conditions may develop near showers and
thunderstorms, which are expected to become more active tonight into
early next week. A long period northeasterly swell is expected to
spread across the Atlantic waters Saturday night into Sunday.

&&

.BEACH FORECAST...

Today, there is a moderate risk of rip currents along the
northwestern, northern and eastern coasts of Puerto Rico including
Culebra, which means life-threatening rip currents are still
possible in those areas. A low risk remains in place elsewhere.
The risk is expected to increase to high along north exposed
beaches by Saturday night into Sunday, as a northeasterly swell
will start to spread across the Atlantic waters.

&&

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

$$

SHORT TERM/AVIATION...CVB
LONG TERM/MARINE/BEACH FORECAST...YZR

NWS SJU Office Area Forecast Discussion