National Weather Service Today's Weather Impact Levels

965
FXCA62 TJSJ 230717
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
317 AM AST Mon Mar 23 2026

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

.KEY MESSAGES...
Issued at 309 AM AST Mon Mar 23 2026


 * A high risk of rip currents will persist across the northern
   and northeastern beaches of Puerto Rico until 6 PM AST this
   evening. A moderate risk will remain for the rest of the areas.

 * Hazardous Marine conditions remain hazardous with seas up to 7
   feet across the offshore Atlantic waters. Therefore, a Small
   Craft Advisory is in effect.

 *  A variable weather pattern will promote periods of passing
showers, with light to moderate rainfall possible during the
morning, followed by localized afternoon convection, especially
across interior and western Puerto Rico.

 * Across the U.S. Virgin Islands, variable conditions will prevail
   with passing showers moving in from the east, leading to brief
   reductions in visibility and occasional wet conditions
   throughout the day.


&&

.Short Term(Today through Wednesday)...
Issued at 309 AM AST Mon Mar 23 2026

During the night into the early morning hours, mostly cloudy skies
prevailed across most of the forecast area. Light to moderate
shower activity was observed early in the morning across portions
of the metropolitan area, specifically affecting municipalities
from Loiza to Dorado. This shower activity was light and did not
result in significant rainfall accumulations. Minimum temperatures
overnight were slightly below normal values; across the coastal
areas, temperatures fluctuated between the low to mid 70s, and in
the mountainous sections, from the upper 50s to the lower 60s.

As the frontal boundary and the upper-level trough continue to
move eastward out of the region, a deep layer of trapped moisture
at 850 mb will be the main driver for a showery pattern today,
with GOES-derived satellite imagery indicating precipitable water
values ranging between 1.5 and 1.7 inches, remaining above normal
climatological levels; this surface moisture will combine with
local and diurnal effects to produce light to moderate passing
showers in the morning, followed by more localized deep
convection. Surface winds will remain from the northeast as a
surface high-pressure system over the western Atlantic extends
into the Caribbean, a pattern that will favor shower development
around 12 PM across northeastern sections of the island before
shifting toward the southwestern quadrant of the region. Given
that instability has decreased, widespread thunderstorm activity
is not expected; however, one or two isolated thunderstorms cannot
be ruled out, especially in the strongest areas.

According to global model guidance, a change in the wind pattern
is expected on Tuesday due to the According to global model
guidance, a change in the wind pattern is expected on Tuesday due
to the combined influence of a surface high-pressure system
building over the central Atlantic and the passage of a weak
surface perturbation across the region. Under this evolving
pattern, low-level winds will remain from the northeast during the
morning hours before gradually veering to an easterly component
around midday. During the day, the GFS indicates precipitable
water values fluctuating between 1.4 and 1.6 inches, near to
slightly above climatological normals, supporting a high potential
for shower development across the islands. Morning shower activity
will primarily affect northeastern Puerto Rico and the U.S. Virgin
Islands, followed by the development of afternoon convection along
the Cordillera Central and into the western interior, aided by
local effects and diurnal heating. During the nighttime hours,
the available moisture may enhance additional shower activity
across the local waters and adjacent coastal areas. By Wednesday,
a similar pattern is expected to persist under the continued
influence of the surface high, with easterly winds gradually
becoming more southeasterly by the afternoon, promoting a warmer
temperatures.

&&

.Long Term(Thursday through Monday)...
Issued at 309 AM AST Mon Mar 23 2026

Moisture is expected to remain elevated from Thursday through the
weekend, with precipitable water (PW) values generally in the 1.50
to 1.80 inch range or above normal values for late March. Increased
low and mid-level moisture, along with a weak mid- to upper-level
trough moving through the region and weak surface perturbations,
will support frequent periods of cloudiness and showers.
Temperatures near 500 mb are forecast to remain around 6 to 8
degrees C, indicating moderate instability. This environment may
support periods of moderate to heavy showers, particularly on
Friday. Regardless, widespread organized convection is not
anticipated. Enhanced cloud cover should limit daytime heating,
keeping high temperatures near typical seasonal values. Winds are
expected to gradually increase to 15 to 20 knots, with locally gusty
conditions in and near shower activity.

Over the weekend, unsettled conditions are expected to persist as
moisture remains elevated and weak disturbances remain near the
region. This will result in continued periods of showers or simply
increased cloud cover. Overall weather conditions will remain wet
and somewhat variable.

Conditions are expected to gradually improve during the upcoming
workweek as a drier airmass filters into the area. Shower coverage
should decrease, while temperatures remain near seasonal norms.

&&

.AVIATION...
(06Z TAFS)
Issued at 309 AM AST Mon Mar 23 2026

VFR conditions are expected to prevail across all TAF sites
throughout the forecast period. Brief MVFR conditions are
possible, particularly at TJPS between 23/18Z and 23/21Z, due to
reduced VIS and lower CIGs associated with localized convection
over the interior and mountainous areas. Low-level winds will
remain from the E-NE at less than 8 knots early, increasing to
around 15 knots after 23/15Z . Winds will then diminish after
23/23Z, becoming light overnight. Overall, conditions will remain
favorable for aviation operations, except for brief, localized
impacts from afternoon convection.

&&

.MARINE...
Issued at 309 AM AST Mon Mar 23 2026

Some influence of a frontal boundary lingering near the region and
a surface high pressure over the western Atlantic will continue
to promote unsettled marine conditions today, with lingering
showers and a slight chance of thunderstorms across the local
waters. A fading long- period northerly swell will maintain
hazardous seas across the Atlantic waters through this evening.
However, moderate to locally fresh north- northeasterly winds will
produce choppy seas, particularly across the Mona Passage and
offshore Atlantic waters. A surface high pressure building from
the western to central Atlantic will maintain northeasterly winds
through the first part of the week, with increasing winds and seas
expected by midweek.

&&

.BEACH FORECAST...
Issued at 309 AM AST Mon Mar 23 2026

Life-threatening rip currents are expected along the north-facing
beaches of Puerto Rico, from Aguadilla to Fajardo, through this
afternoon 6 PM AST, with a High Risk of rip currents. A moderate
risk is in effect for Vieques, Culebra, and the U.S. Virgin
Islands. Beachgoers should stay cautious, remain near lifeguards,
and avoid the water if unsure about conditions.

Looking ahead, an increase in winds around the middle of the week
will broaden the rip current risk across most beaches in Puerto Rico
and the U.S. Virgin Islands, potentially leading to more widespread
hazardous marine and coastal conditions.For more information and
specific rip current details, please visit:https://www.weather.gov/beach/sju

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk through this afternoon for PRZ001-002-005-
     008.

     High Rip Current Risk until 6 AM AST early this morning for
     PRZ010.

VI...None.
AM...Small Craft Advisory until 6 PM AST this evening for AMZ711.

&&

$$

SHORT TERM...LIS
LONG TERM....MMC
MARINE & BEACH FORECAST...CAM

NWS SJU Office Area Forecast Discussion