National Weather Service Today's Weather Impact Levels

277
FXCA62 TJSJ 280824
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
424 AM AST Sat Mar 28 2026

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

.KEY MESSAGES...
Issued at 417 AM AST Sat Mar 28 2026

* A wet and unsettled weather pattern will persist across the
  region today, with the most active period expected during the
  afternoon hours. Scattered to numerous showers and thunderstorms
  are likely, particularly across interior and western/southwestern
  Puerto Rico.

* This may lead to urban and small stream flooding, along with quick
  river rises, especially in areas that have received recent
  rainfall. The strongest thunderstorms may also produce gusty winds
  and locally heavy rainfall.

* For the U.S. Virgin Islands, passing showers and isolated
  thunderstorms are expected, with periods of ponding of water on
  roads and in low-lying areas.

* Marine and coastal conditions are expected to deteriorate early
  next week as a northerly swell arrives. This will likely result
  in Small Craft Advisories and Rip Current Statements, with
  hazardous breaking waves and dangerous surf conditions possible.
  High Surf Advisories cannot be ruled out.

&&

.Short Term(Today through Monday)...
Issued at 417 AM AST Sat Mar 28 2026

A fairly active afternoon and evening was observed across Puerto
Rico on Friday, with several Flood Advisories, Flash Flood Warnings,
and Flood Warnings issued. Heavy rainfall resulted in flooding
reports, mostly over portions of Puerto Rico, including reports of
the Rio Culebrinas out of its banks. By early in the night,
thunderstorm activity gradually diminished, transitioning into more
stratified rainfall as the most active convection shifted away from
the region.

The overall pattern has not changed much, with a wet and unsettled
weather pattern expected to persist. For today, winds will gradually
shift from east-southeast to east-northeast to northeast, promoting
a more focused area of convection across interior and southwestern
Puerto Rico during the afternoon hours. Although slight warming
aloft will result in somewhat reduced instability compared to
previous days, conditions will remain favorable for shower and
thunderstorm development. In addition, the 90-100 kt subtropical jet
will remain better positioned aloft, enhancing upper-level
ventilation and potentially adding intensity to thunderstorm
activity this afternoon. Given recent rainfall, soils remain
saturated, and streamflows are elevated. Therefore, any additional
rainfall will increase the risk of urban and small stream flooding,
as well as rapid river rises. Flooding impacts could develop
quickly, particularly across interior and western/southwestern
Puerto Rico. Landslides and rockfalls will also remain possible in
areas of steep terrain.

By Sunday, conditions are expected to improve as drier air filters
into the region. Model guidance indicates 700-500 mb relative
humidity values decreasing from well above normal levels, previously
exceeding two standard deviations above climatology, to below
normal levels. This will result in a reduction in shower and
thunderstorm activity, making Sunday the driest day of the period.
However, isolated afternoon convection cannot be ruled out,
particularly across western/southwestern Puerto Rico.

On Monday, moisture will increase once again, with precipitable
water values rising to near or above normal levels and mid-level
moisture rebounding to around 40-60 percent. Under a
northeasterly wind flow and continued troughiness aloft, another
round of afternoon convection is expected. Activity is expected to
be less widespread compared to previous days, but localized heavy
rainfall will still be possible. Overall, despite a brief
improvement on Sunday, the combination of saturated soils,
elevated rivers, and additional rounds of convection will continue
to pose a flooding risk through the period.

&&

.Long Term(Tuesday through Saturday)...
Issued at 417 AM AST Sat Mar 28 2026

Strong low to mid level high pressure will maintain a strong
northeasterly wind flow through much of the workweek. The steering
flow is expected to be at 15 to 25 kts. At the upper level, the jet
stream will maintain speeds of nearly 80 knots. Under the low level
winds, weak disturbances will stream at times across the islands.
This will maintain the probability of precipitation on the medium
and high side. In general, showery weather will persist for most of
the Virgin Islands and eastern Puerto Rico. Then, in the afternoon,
diurnal heating will trigger showers and thunderstorm along the
interior and western Puerto Rico. Because the winds are expected to
be strong, the risk of flooding will be mostly limited. Impacts may
include hazardous driving conditions due to low visibility and
ponding of water. In the west, urban and small stream flooding could
still occur, although not widespread.

&&

.AVIATION...
(06Z TAFS)
Issued at 417 AM AST Sat Mar 28 2026

Mainly VFR conds will prevail across most terminals. Sct SHRA ovr
lcl waters and btw terminals may cause brief MVFR/IFR CIGs/VIS. Aft
28/16z, SHRA/TSRA incr across PR, mainly affecting interior/W & S
terminals (TJBQ/TJPS) with TEMPO MVFR/IFR conds. VCTS exp at
TJSJ/TJPS/TJBQ, with PROB30 TSRA at TJBQ/TJPS. USVI (TIST/TISX), VFR
prevails with VCSH and brief MVFR psbl. Winds lgt/VRB bcmg E-NE
8-14 kt aft 14z, with higher gusts near TSRA and sea breeze
variations.

&&

.MARINE...
Issued at 417 AM AST Sat Mar 28 2026

A mid to upper-level trough will continue to promote unstable
weather across the region today, supporting scattered showers and
thunderstorms. A surface inverted trough northeast of the area will
maintain light to moderate east-northeast winds this afternoon,
increasing to moderate to fresh on Sunday and resulting in choppy
seas. A cold front will approach from the western Atlantic early next
week, followed by stronger winds for the rest of the week. In
addition, a long- period northerly swell will build across the local
waters beginning late Monday night, leading to hazardous marine
conditions through at least Thursday. These conditions will be
dangerous for small craft operators.

&&

.BEACH FORECAST...
Issued at 417 AM AST Sat Mar 28 2026


Today, a moderate risk of rip currents persists along the north-
facing beaches of Puerto Rico, Culebra, and the U.S. Virgin Islands,
while south-facing beaches and Vieques will experience a low risk.
Beachgoers should continue to exercise caution as a moderate risk
means that life-threatening rip currents are possible in the surf
zones.

Beach conditions are expected to worsen early next week. The arrival
of a long-period northerly swell, combined with strengthening winds
from late Monday night through the rest of the week, will likely
lead to a high risk of rip currents along exposed coastlines.
Hazardous surf and life-threatening rip currents are anticipated,
especially along north-facing beaches.

Beachgoers are urged to use caution and continue to monitor the
forecast for any updates. Always swim near a lifeguard and follow
local safety guidance. For additional information and location-
specific rip current details, please visit: weather.gov/beach/sju

&&

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

$$

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

NWS SJU Office Area Forecast Discussion