National Weather Service Today's Weather Impact Levels

588
FXCA62 TJSJ 311950 CCA
AFDSJU

Area Forecast Discussion...CORRECTED
National Weather Service San Juan PR
350 PM AST Tue Mar 31 2026

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

.KEY MESSAGES...
Issued at 220 PM AST Tue Mar 31 2026

* Hazardous beach conditions continue: Life-threatening rip
  currents and dangerous surf will persist along north- and east-
  facing beaches of Puerto Rico and the U.S. Virgin Islands. Avoid
  entering the water in these areas.

* Periods of showers and isolated thunderstorms: Passing showers
  will affect the region overnight and during the morning, with
  additional afternoon showers and isolated thunderstorms mainly
  across western Puerto Rico. Brief heavy rain may lead to
  localized flooding, especially in urban areas with poor
  drainage.

* Isolated thunderstorms possible this afternoon: Some storms may
  produce lightning, brief heavy rainfall, and gusty winds.

* Breezy conditions persist: Breezy to locally windy conditions
  will continue, especially along coastal and exposed areas,
  allowing showers to move quickly across the region.

* Impacts on daily activities: Outdoor and holiday plans may be
  affected by rain and hazardous marine conditions. Stay alert for
  changing weather conditions and follow local safety guidance.

&&

.Short Term(This evening through Thursday)...
Issued at 220 PM AST Tue Mar 31 2026

Fair weather prevailed today across the islands as a somewhat
drier air mass moved across the archipelago of PR and the USVI.
However, showers embedded in the trades occasionally moved inland
across the windward areas. The trade winds were mainly 10 to 20
mph, with gusts up to 25 mph. Most coastal and urban sites
recorded maximum temperatures in the mid- to upper 80s, while
mountain sites recorded maximum temperatures in the mid-70s.

Showers with the possibility of one or two thunderstorms are
still possible across the interior and southwest sections through
this evening. While the northeasterly winds will continue to
advect patches of clouds producing showers across the windward
locations of PR and the US Virgin Islands, especially from late
tonight into early Wednesday morning, when low-level convergence
could enhance this activity, which may lead to a limited risk of
flooding.

Looking ahead, northeasterly winds will continue to affect the
region, with breezy to locally windy conditions through the short-
term period, leading to periodic increases in moisture and
rainfall across windward locations, followed by afternoon
convection across the interior and southwest quadrant each day.

Meanwhile, high surf conditions will lead to life-threatening rip
currents along north-facing beaches of St Thomas, St John, and
adjacent Islands, Puerto Rico, including Culebra and Vieques,
through the rest of the short term. A long-period northerly swell
will bring: High surf, Life-threatening rip currents, and Possible
coastal erosion. If you plan to visit the beach, use extreme
caution and consider south- or Caribbean-facing beaches, where
conditions are safer.

&&

.Long Term(Friday through Tuesday)...
Issued at 230 AM AST Tue Mar 31 2026

From Friday into Saturday, an evolving pattern under the influence
of an induced surface trough and a shortwave trough will enhance a
more unstable weather pattern across the islands. At the surface,
the induced surface trough, in combination with a surface high
pressure over the Central Atlantic, will promote a northeasterly
wind flow across the area, rapidly shifting to the east-southeast
early Friday as the surface perturbation moves west of the region.
At the upper levels, a shortwave trough will move across the region,
favoring enhanced instability and thunderstorm development. This
pattern will support a high chance of showers across the area;
however, the forecast will be largely dependent on surface
conditions at the time. According to global model guidance and
relative humidity values, a deep upper-level cloud layer may inhibit
the diurnal heating trigger. If sufficient heating does not develop,
widespread shower activity is not anticipated; however, some well-
developed showers are still expected across the northwestern section
and the San Juan Metropolitan area. On Sunday, global model guidance
from the GFS and ECMWF continues to suggest precipitable water
values up to 1.7 inches, which remains near the 75th percentile for
this time of year, consistent with relative humidity values between
850 and 500 mb.

By Monday onward, the main surface weather pattern will be driven by
a broad surface high pressure over the Central Atlantic, resulting
in a tightening of the pressure gradient and increasing winds. Under
this pattern, global model guidance suggests an increase in low-
level moisture across the Caribbean moving into the local islands.
The GFS indicates precipitable water values up to 1.9 inches, which
remains around the 75th percentile through the rest of the period.
Under this setup, reduced upper-level dynamics will limit upper-
level cloudiness, allowing the diurnal heating process to become
more effective. Under this scenario, afternoon convection is likely
to become more widespread and better organized, particularly across
western and interior Puerto Rico, where local effects will enhance
shower and thunderstorm development. This increase in convective
activity, combined with warm and moist conditions, will elevate the
risk of urban and small stream flooding, especially in areas that
experience repeated rainfall. In addition, temperatures are expected
to trend above normal, with coastal highs reaching the low 90s,
further supporting instability and convective potential each
afternoon.

&&

.AVIATION...
(18Z TAFS)
Issued at 220 PM AST Tue Mar 31 2026

VFR conds across all TAF sites. Frequent VCSH anticipated over
TJSJ, TIST, and TJBQ after 30/18Z, then from 31/00Z thru 31/12Z.
Today, winds will remain from NE at 8 to 12kts with occasional
higher gust. Winds are forecasts increase from 31/12Z onwards to
15 - 20 kt and higher gust at times.

&&

.MARINE...
Issued at 220 PM AST Tue Mar 31 2026

Confused and hazardous seas will persist through much of the week
due to fresh to strong northeasterly winds combined with a long-
period northerly swell, creating dangerous conditions for small
craft. Showers will move across the regional waters, especially
late tonight into early Wednesday morning, as a shear line remains
north of the area. A strong Atlantic high-pressure system will
maintain these windy conditions through at least Friday, with
winds gradually shifting to the east; however, choppy to rough
seas will persist even after the wind shift.

&&

.BEACH FORECAST...
Issued at 220 PM AST Tue Mar 31 2026

Dangerous surf conditions are creating life-threatening rip
currents along north-facing beaches of Puerto Rico and the U.S.
Virgin Islands, where entering the water is strongly discouraged.
While south-facing beaches have a lower risk, caution is still
advised as conditions can change quickly. Hazardous marine
conditions will persist through much of the week, with a High Surf
Advisory in effect through at least late Wednesday night and a
continued high risk of rip currents beyond that. Beachgoers should
remain alert, follow local safety guidance, and only swim near
lifeguards.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk through Friday evening for PRZ001-002-005-
     008-010-012.

     High Surf Advisory until 6 PM AST Wednesday for PRZ001-002-005-
     008-010-012-013.

     High Rip Current Risk through late Wednesday night for PRZ013.

VI...High Rip Current Risk through Friday evening for VIZ001.

     High Surf Advisory until 6 PM AST Wednesday for VIZ001.

AM...Small Craft Advisory until midnight AST Friday night for AMZ711-
     712-716-723-741-742.

     Small Craft Advisory until 6 AM AST Thursday for AMZ726.

&&

$$

KEY MESSAGES/SHORT TERM/MARINE/BEACH FORECAST...CAM
LONG TERM...LIS
AVIATION...MMC

NWS SJU Office Area Forecast Discussion