National Weather Service Today's Weather Impact Levels

851
FXCA62 TJSJ 150826
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
426 AM AST Sat Feb 15 2025

.SYNOPSIS...

Breezy conditions will continue today, with a trade wind
perturbation bringing an increase in showers with periods of
locally heavy rainfall through at least this afternoon. East to
southeasterly winds and drier conditions are expected on Sunday.
Another trade wind perturbation moves from the east on Monday
increasing shower activity once again. Fair weather conditions
with occasional trade wind showers are expected through the rest
of the workweek.


&&

.SHORT TERM...Today through Monday...

More frequent light to moderate showers from the NE persisted
overnight, with breezy to windy conditions across coastal areas of
the local islands. Doppler radar rainfall estimates from 00z along
northern and eastern PR ranged from 0.20-0.75 inches with
localized areas near 1 inch. Stations located at St. John and St.
Croix observed accumulations from 0.05 to 0.09 inches. Seasonal
temperatures were observed across the region, with stations at
lower elevations reporting low to mid 70s while higher elevations
remained in the low to mid 60s. Stations along coastal areas,
mainly at windward sections, reported gusty winds up to 30 knots.

A variable weather pattern along breezy to windy conditions with
gusty winds will continue for the rest of the weekend and the
beginning of the work week. The surface high pressure in the western
Atlantic migrating eastward will continue to promote strong trade
winds and filter patches of moisture into the region. Based on
current satellite and radar images, shower activity will continue in
the morning along windward sections and shallow convection over
southwestern PR in the afternoon. By Sunday, PWAT values will
decrease to below climatological normal and winds will slow down and
have a southerly component, maintaining the highest moisture content
north of the region and a drier air mass filtering into the region.
Additionally, this will promote near to above climatological normal
temperatures along the forecast area, mainly over urban and coastal
areas. Winds will return from the E-ENE by Monday, and another patch
of moisture will arrive in the morning hours. The mid level ridge
will continue lingering north of the region for the next several
days, maintaining a strong cap inversion and promoting stability
aloft. This will also limit deep convective activity and remain
shallow for western Puerto Rico in the afternoons. The risk of
flooding remains low, however, is likely to observe ponding of water
along roadways, urban, and poorly drained areas.

.LONG TERM...Monday through Friday...

A low to mid-level ridge over the central Atlantic will promote
moderate to locally fresh (15-20kt) trade winds across the area
for most of the forecast period. Embedded in this wind flow, trade
wind perturbations induced by a short-wave trough across the
Tropical Atlantic will reach the local area from time to time. The
500 mb temperatures are expected to remain between -6C and -8C
through Wednesday as the upper-level trough moves further eastward
over the Tropical Atlantic, and warming up to -4C into the
weekend. However, the precipitable water content will remain below
normal levels through the workweek (1.00-1.25 inches), and
increase between 1.50-1.75 inches by Friday night into Saturday
morning.

At least through the workweek, a similar weather pattern is
expected with shallow moisture content bringing occasional passing
showers across the windward areas of the islands during the
night/early morning hours. Late in the workweek into the weekend,
a deep layered trough and associated surface trough will move
across the western Atlantic,  pushing eastward the ridge across
the central Atlantic, and promoting a weakness over the area with
the arrival of a surface trough from the east and higher moisture
content. As the pressure gradient relaxes, light to moderate
trades (10-15 kt) are expected on Friday. Therefore, showers with
periods of locally heavy rains are expected to increase with the
passage of the surface trough from Friday through Saturday.

Seasonal temperatures will persist, with daytime highs reaching
the mid-80s across the U.S. Virgin Islands and the north/eastern
sections of Puerto Rico. In contrast, the southern to western
coast of Puerto Rico may experience temperatures ranging from the
mid-80s to low 90s. Minimum temperatures are generally expected to
range from the low to mid-70s in coastal areas to the upper 50s
and low 60s in higher elevations.


&&

.AVIATION...

(06z TAFs)

VFR conds for all terminals, with -RA at windward sections due to
showers embedded in the trades that will decrease by 15/12z and
become VCSH until 15/18z. -SHRA btw 15/06-15/08z for TJBQ, reducing
CIG/VIS and temporary MVFR conds. E-ENE from 10 to 20 kt and gust
from 20 - 30 kt btw 15/12-15/23z, reducing to 5-15 kt along all TAF
sites.


&&

.MARINE...

Strong trades (20-25 kt) are expected today. Seas up to 8 feet
will continue across the Atlantic waters through Sunday, and up to
7 feet across most coastal waters and Passages. Therefore, a Small
Craft Advisory (SCA) remains in effect for these waters through at
least Sunday. Seas up to 7 feet may continue across the offshore
Atlantic waters early in the workweek and the SCA could be
extended once again.


&&

.BEACH FORECAST...

Short period wind-driven waves will maintain a high risk of rip
currents across the northern and eastern beaches of the islands
through at least early Sunday morning. A low to moderate risk of
rip currents will prevail across the south to southwest coast of
Puerto Rico.


&&

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

     High Rip Current Risk until 6 AM AST early this morning for
     PRZ003.

VI...High Rip Current Risk through late tonight for VIZ001-002.

AM...Small Craft Advisory until 6 PM AST Sunday for AMZ711-723-733-
     741.

     Small Craft Advisory until 6 AM AST Sunday for AMZ712.

     Small Craft Advisory until 6 PM AST this evening for AMZ716-726-
     735.

&&

$$

SHORT TERM...MNG
LONG TERM....DS
AVIATION...MNG

NWS SJU Office Area Forecast Discussion