Your Number One Source for Real-Time Puerto Rico Weather & Hurricane Tracking Updates

834
FXCA62 TJSJ 031819
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
219 PM AST Fri Apr 3 2026

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

.KEY MESSAGES...
Updated at 215 PM AST Fri Apr 3 2026

* Life-threatening rip currents will continue along north- and east-
  facing beaches of Puerto Rico and the U.S. Virgin Islands through
  early next week. Stay out of the water in high-risk areas.

* Choppy to rough seas will result in hazardous marine conditions
  through early next week, small craft must exercise caution.

* Showers and thunderstorms will develop each afternoon, becoming
  more widespread and stronger through the weekend and into early
  next week. Flooding risk will remain elevated, with locally higher
  impacts possible, especially across Puerto Rico.

* Breezy to locally windy conditions will continue across Puerto
  Rico and the U.S. Virgin Islands, with stronger gusts in exposed
  areas and near showers.

&&

.Short Term(This evening through Sunday)...
Issued at 215 PM AST Fri Apr 3 2026

High pressure over the Atlantic will continue to promote breezy ENE
flow this afternoon. This steering flow, however will gradually veer
to become more easterly tonight and easterly to ESE on Saturday and
ESE on Sunday. Current satellite-derived precipitable water (PWAT)
values indicate that the region is between a drier airmass (PWAT
values around 1.30 in) to the north and a moist airmass over and
south of the region (PWAT values around 1.50 to 1.70 in). Diurnal
heating, along with the ENE flow will continue to result in the
development of showers and isolated t-storms over the Cordillera
towards the southwestern quadrant of PR, as well as showers over the
northern USVI towards Culebra and eastern Puerto Rico, over St.
Croix and mainly downwind of Vieques. This will result in a limited
to elevated flooding risk over mainly over the southwestern quadrant
of Puerto Rico. Although these afternoon showers will gradually
dissipate and/or move offshore, passing shower activity is expected
over windward sectors late tonight as a moist air mass approaches
the region. Afternoon convection, including possible isolated t-
storms, is forecast for each day across interior and western Puerto
Rico, depending on the prevailing steering flow each day. With
easterly to ESE winds on Saturday, afternoon convection can
concentrate over W-NW PR and downwind of the local islands and El
Yunque, and with ESE flow on on Sunday, prompting afternoon
convection over NW PR and downwind of the local islands and El
Yunque. Increasing moisture over the region (PWAT values will reach
above normal, 1.75 in), a nearby upper trough, the lack of a defined
trade wind cap and a jet over the region will help shower and t-
storm development. A limited to elevated flooding risk will persist
over the weekend, resulting in ponding of waters over roads and
poorly drained areas. Flooding in urban areas, roads, small streams
and washes. There is a chance of isolated flash floods, please
continue to monitor for updates. Breezy to locally windy conditions
will continue across coastal areas of the islands and can serve to
limit rainfall accumulations. Increasing cloud cover at times may
limit overall coverage and afternoon convection, especially on
Saturday. By Sunday, conditions become more favorable for stronger
convection, especially during the afternoon. The ESE flow will steer
a warmer and more humid airmass over the region.  925 mb wind speeds
will be at 15-20 kts throughout the short term period, promoting
quicker moving showers towards windward areas, especially during the
morning/overnight hours. 925 temperatures will be below normal to
normal (warmer under the ESE flow), gradually increasing throughout
the short term period.

&&

.Long Term(Monday through next Thursday)...
Issued at 200 AM AST Fri Apr 3 2026

A warm and humid pattern remains on track across the northeastern
Caribbean through most of the upcoming week, supporting enhanced
afternoon convection and a limited to elevated flooding threat
across the local islands.

At the surface, a strong high-pressure system migrating from the
central to eastern Atlantic will maintain south to southeasterly
winds through mid-week. This flow will transport abundant tropical
moisture from the Caribbean Sea into the region, with precipitable
water (PWAT) values forecast between 1.90 and 2.00 inches
throughout the period. Under this pattern, isolated to scattered
showers are expected across eastern Puerto Rico and the U.S.
Virgin Islands during the morning hours, followed by daily
afternoon convection across central, northern, and northwestern
Puerto Rico. Daytime heating and local effects will further
enhance shower and thunderstorm development. This pattern,
combined with high humidity, will elevate the risk of urban and
small stream flooding, as well as quick river rises.

As the week progresses, a mid- to upper-level shortwave trough
will support the development of a surface trough near Hispaniola,
enhancing moisture pooling across the region. By Wednesday, 500 mb
temperatures are forecast to drop to around -9C, increasing
instability aloft and supporting stronger thunderstorm
development. Temperatures are expected to trend warmer early in
the period, with 925 mb values rising above climatological normals
from Tuesday onward, further supporting afternoon convective
activity.

&&

.AVIATION...
(18Z TAFS)
Issued at 215 PM AST Fri Apr 3 2026

Mainly VFR conditions through the period. Brief MVFR conditions are
possible mainly at TJPS as -SHRA and and VCTS develops through
around 03/22z.  VCSH/-SHRA reaching mainly northern and eastern
sites from the Atlantic under ENE flow. ENE winds at 12 to 20 kts
with higher gusts through this evening, veering to become more E and
weakening overnight, and increasing again after 04/13Z from the E to
ESE. VCSH/-SHRA reaching mainly northern and eastern sites.

&&

.MARINE...
Issued at 215 PM AST Fri Apr 3 2026

No changes were made to the marine forecast, as hazardous conditions
will continue through the weekend and into early next week. Current
nearshore buoys are reporting seas between 4 and 6 feet, while the
Ponce and St. John buoys have lowered, between 2 and 3 feet.
Additionally, the latest altimeter scans near the CWA show seas
between 7 and 8 feet over the Atlantic, while Caribbean waters
remain lower (below 6 feet). NDBC buoy 41043 has shown a gradual
decrease in seas, meaning that the swell is gradually subsiding.
Nevertheless, the remaining energy from the swell will continue to
spread across the local Atlantic waters and passages today,
gradually subsiding by Sunday. The broad surface high pressure over
the western Atlantic will maintain moderate to locally fresh
northeasterly winds, veering from the east-southeast by tomorrow,
Saturday. Combined with the subsiding northeasterly swell, seas will
remain choppy to rough, especially across the Atlantic waters and
local passages. Small Craft Advisories remain in effect for the
Atlantic offshore and coastal waters, including the Anegada and Mona
Passages, through Sunday afternoon.

Trade wind showers will continue across the waters, with isolated
afternoon thunderstorms possible over coastal waters, mainly over
western Puerto Rico. Small craft must exercise caution, as showers
and isolated thunderstorms may result in reduced visibility, gusty
winds, and lightning.


&&

.BEACH FORECAST...
Issued at 215 PM AST Fri Apr 3 2026

Beaches over northern and eastern Puerto Rico, including Vieques and
Culebra, and the U.S. Virgin Islands, will remain hazardous for
beachgoers this weekend. The northeasterly swell continues to spread
across the Atlantic waters and passages, with breezy to locally
windy conditions across coastal areas of the islands. The San Juan
and Arecibo buoys are currently reporting seas around 6 feet, with a
period between 10 and 11 seconds.  Taking into consideration
bathymetry, these could result in breaking waves between 7 and 9
feet, posing a threat to beachgoers. As mentioned in the Marine
section, NDBC buoy 41053 keeps reporting remaining energy from the
swell, which will continue to spread across local Atlantic waters
and passages. Given the current conditions and expected forecast,
the Rip Current Statement remains in effect along the northern and
eastern beaches of Puerto Rico, including Vieques and Culebra, and
the U.S. Virgin Islands through Sunday afternoon. Beachgoers and
inexperienced surfers are urged to avoid going into the water,
walking over rocks or jetties, as life-threatening rip currents are
very likely. Heed the advice of lifeguards, beach patrol flags, and
signs.

In addition to the life-threatening rip currents,  beachgoers
visiting beaches over south/southwestern Puerto Rico should stay
weather alert due to isolated showers and thunderstorms capable to
produce gusty winds, periods of heavy showers, and lightning. Seek
shelter inside a building whenever you hear lightning.

&&

.HYDROLOGY...
Issued at 200 AM AST Fri Apr 3 2026

Hydrologic conditions will become increasingly favorable for
flooding impacts through the weekend, although uncertainty remains
regarding rainfall coverage and persistence. Flooding is not
expected to be widespread; however, an elevated risk of urban and
small stream flooding is anticipated, with isolated flash flooding
possible. Recent rainfall has resulted in saturated soils,
especially across eastern and northern Puerto Rico, which will
allow water to run off quickly and lead to rapid rises in streams
and rivers, including water surges (golpes de agua) in steep
terrain. A shift in the pattern will bring more afternoon activity
toward northwestern Puerto Rico, and the San Juan streamer could
still produce periods of rainfall across the metro area, posing a
localized flooding risk.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk through Sunday afternoon for PRZ001-002-
     005-008-010-012-013.

VI...High Rip Current Risk through Sunday afternoon for VIZ001-002.

AM...Small Craft Advisory until 6 PM AST Sunday for AMZ711-712-716-
     723-741.

&&

$$

SHORT TERM/AVIATION...MRR
LONG TERM...CVB
MARINE/BEACH FORECAST...MNG
HYDROLOGY...ICP

NWS SJU Office Area Forecast Discussion