177
FXCA62 TJSJ 240609
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
209 AM AST Tue Feb 24 2026

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

.KEY MESSAGES...
Issued at 142 AM AST Tue Feb 24 2026

* Shower and thunderstorm activity expected to increase this
  afternoon across the interior of Puerto Rico, where there is an
  elevated flood threat.

* Across the USVI, passing showers will increase early this
  morning, with a drying trend expected on Wednesday.

* A long period northwesterly swell will bring hazardous seas,
  life-threatening rip currents and high surf conditions from
  Wednesday through at least Friday. Continue to monitor the
  forecast in the coming days and heed the advice of lifeguards,
  flags and signs.

* Minor concentrations of Saharan dust are expected to filter late
  tonight.

&&

.Short Term(Today through Thursday)...
Issued at 142 AM AST Tue Feb 24 2026

A col area north of the region and a developing pre-frontal trough
will bring a surge in low-level moisture today, with precipitable
water content increasing around 1.75 inches by this afternoon. At
the upper levels, a trough will promote colder 500 mb temperatures
around -8.5C through at least Wednesday. Therefore, expect showers
to increase in coverage and intensity, with isolated thunderstorm
development. There is an elevated flood threat(urban and small
stream flooding, with possible isolated flash flooding) for most of
the interior and western sections of PR today, and a limited flood
threat across the USVI, Vieques, Culebra, and the eastern portions
of PR, where ponding of water on roads and minor flooding is
possible. On Wednesday, although moisture content will fluctuate
around climatology (1.40-1.70 inches), a drier air mass with minor
concentrations of Saharan dust will filter from the east overnight
and through the early morning hours, and limit shower activity
gradually across the USVI and eastern sections of PR. However, the
available moisture content, combined with daytime heating and local
effects will trigger shower and isolated thunderstorm activity over
western PR in the afternoon hours. Gusty winds and locally heavy
rainfall is possible with this activity. Meanwhile, a surface high
pressure strengthening over the Central Atlantic, will promote
moderate to locally fresh easterly winds and bring low-level clouds
and passing showers from the Tropical Atlantic into the local area
through Thursday. Rainfall totals on Thursday should not cause
flooding concerns due to the fast moving nature of the showers, and
as an overall drier air mass remains in place, with PWAT dropping
below climatology.

Daytime temperatures will drop around 2-4 degrees compared to
yesterday as showers increase today, and the stronger trades (15-20
knots) return through the rest of the short-term period. Highs are
forecast to range from the mid 80s to the upper 80s across the lower
elevations, to the mid 70s across the higher elevations.

&&

.Long Term(Friday through Tuesday)...
Issued at 142 AM AST Tue Feb 24 2026

A broad surface high pressure system across the Central Atlantic
will be the dominant weather feature for most of the period across
the forecast area. This system will promote moderate to locally
fresh easterly winds on Friday. Under this wind pattern, patches of
shallow moisture with precipitable water values from 1.4 to 1.7
inches will move across the islands, enhancing cloudiness and
supporting a showery pattern, especially across the U.S. Virgin
Islands and eastern Puerto Rico during the morning hours. On
Saturday, a slight variation in the wind pattern is forecast, with
winds veering as the surface high interacts with an induced pre-
frontal trough over the western Atlantic and its associated
frontal boundary. This interaction will maintain moderate
southeasterly winds from Saturday through Monday. Therefore, the
islands can expect persistent patches of shallow but sufficient
moisture to sustain a variable and showery weather pattern during
this period. Morning showers are expected across portions of the
U.S. Virgin Islands, followed by afternoon convection,
particularly across the northwestern quadrant of Puerto Rico and
the San Juan metropolitan area, aided by showers developing near
the El Yunque region in streamers. Although showers may be locally
significant, especially in the afternoon, widespread flooding is
not anticipated. Minor flooding may occur in low-lying and urban
areas. Breezy conditions are also expected, as suggested by 925
mb winds ranging between 18 and 20 knots.

By Tuesday, an increase in surface moisture is forecast as a frontal
boundary approaches north of the islands, with associated cloudiness
and moisture slightly above the climatological normals reaching the
northern sections of Puerto Rico. The approach of this system will
promote a more pronounced easterly wind pattern across the region.
As a result, showers are expected across eastern Puerto Rico and
along the north and northeast coasts. Residents and visitors are
urged to stay tuned for further updates.

&&

.AVIATION...
(06Z TAFS)
Issued at 142 AM AST Tue Feb 24 2026

Mainly VFR early in the fcst period across all terminals.
SHRA/TSRA expected to develop along the interior and western PR
btw 24/16-22z. This may cause tempo MVFR conditions across the PR
terminals, and mtn tops obscd. Low-level winds expected E-ESE up
to 12 kt with a northerly component at TJBQ/TJSJ from late this
morning through the mid-afternoon hours due to the sea breeze.

&&

.MARINE...
Issued at 142 AM AST Tue Feb 24 2026

An approaching front from the western Atlantic and a developing
pre-frontal trough will promote light and variable winds today
across the Atlantic waters and the Mona Passage. Shower activity
and the potential for isolated thunderstorms will increase from
this afternoon through tonight. A long-period north-northwesterly
swell is expected to spread across the Atlantic waters and
passages from late tonight into Wednesday morning, building seas
between 6 and 9 feet. Hazardous seas are expected to linger
through Friday, and Small Craft Advisories are in effect. Moderate
to fresh trades will return during the second part of the
workweek, as surface high pressure builds over the Central
Atlantic.

&&

.BEACH FORECAST...
Issued at 142 AM AST Tue Feb 24 2026

A moderate risk of rip currents will continue along the north and
east-facing beaches of Puerto Rico, including Culebra and Vieques,
as well as St. Thomas, St. John, and St. Croix. Be aware that life-
threatening rip currents can occur, especially in exposed beaches
near rocks, piers, and jetties.

A long-period northwesterly swell will arrive late tonight into
early Wednesday morning, peaking between Wednesday evening and early
Thursday morning. This will increase the risk of rip currents to
high, beginning Wednesday morning, with hazardous conditions (high
surf, minor beach erosion, and life-threatening rip currents) expected
through Friday.

For safety, always check local conditions before swimming. Beach
goers and unexperienced surfers are urged to avoid beaches exposed
to the northerly swell. Remember to swim near a lifeguard, never
swim alone, and, if caught in a rip current, stay calm and float
rather than fight it.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...None.
VI...None.
AM...Small Craft Advisory from 6 AM Wednesday to noon AST Friday for
     AMZ711-712-716-723-741-742.

&&

$$

SHORT TERM...DSR
LONG TERM....LIS
AVIATION...DSR
BEACH/MARINE...GRS

NWS SJU Office Area Forecast Discussion