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000
FXCA62 TJSJ 122023
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
423 PM AST Fri Apr 12 2024

.SYNOPSIS...

Breezy conditions and passing showers will continue
through tomorrow morning as the remnants of a front continues to
cross the region. The arrival of drier air tomorrow afternoon
weekend will bring a reduction in rainfall. A mid- to- upper-
level trough and higher moisture content are expected to increase
shower and thunderstorm activity across the islands from Monday
through Wednesday. Hazardous seas and life- threatening rip
currents will continue for the next few days.

&&

.SHORT TERM....Tonight through Sunday...

Breezy conditions prevailed through the day with plenty of passing
showers that according to radar estimates they provided up to 2.5
inches of rain near Vega Baja throughout the day and then during
the afternoon convection brought so far up to an inch and a half
from Las Marias to Rincon. Easterly winds remained steady between
15-20 mph throughout the day and temperatures were in the low 80s
across coastal regions and were slightly lower across higher
elevations.

Passing showers driven by the prevailing flow, will continue to
affect eastern coastal areas and the local waters through the night.
Breezy to windy conditions will continue as a ridge remains anchored
across the central Atlantic Basin. A mid to upper- level ridge and
trade wind inversion together centered over the Greater Antilles
will help prevent any heavy convective activity, however isolated
areas may receive a noticeable amount of rain throughout this period.

Saturday is expected to follow a drier weather pattern as a drier-
than-normal airmass arrive across the region, followed by an even
drier and more stable weather pattern on Sunday morning. However,
with breezy winds isolated passing showers remain possible.
Throughout Sunday night moisture levels will begin to rise and
conditions become more conducive for deep convective development by
early Monday morning. This will result in an increase in shower
activity and flooding risks for the start of next week. Breezy
conditions will persist, posing a limited wind hazard risk.

&&

LONG TERM...Monday through Friday...
/from previous discussion/

On Monday, the surface ridge over the central Atlantic will
weaken, and wind speeds will decrease as a front approaches from
the northwest. However, it will remain well north of the region.
At the same time, a mid-to-upper-level trough will move from the
southwestern Atlantic into the northeastern Caribbean and linger
over the area through midweek, providing good divergence aloft and
favorable dynamics for thunderstorm development as the 500 mb
temperatures are forecast to drop to around minus 8 degrees
Celsius. Meanwhile, an induced surface trough will develop over
the eastern Caribbean, leading to moisture pooling over the
islands. As a result, there is potential for thunderstorm activity
and flooding rains as a wetter and unstable pattern evolves
through at least late Wednesday night. According to model
guidance, there will be a quick drying trend from Thursday onwards
as an upper-level ridge builds from the western Caribbean,
promoting drier air intrusion and warming of the 500 mb
temperatures.

&&

.AVIATION...
(TAFs 18z)

Mainly VFR conditions expected through the forecast cycle. However,
SHRA ovr ctrl mtn range will cause spreading to W and NW PR may
cause brief MVFR conds at TJBQ. Passing SHRA may affect
TJSJ/TIST/TISX/TJPS through the period. ENE winds 15 to 20 knots
with higher gusts, becoming at 10 to 15 knots overnight.


&&

.MARINE...
A surface ridge over the north-central Atlantic and the remnants of
a front will continue to generate fresh to locally strong east-
northeasterly winds. The arrival of drier air tomorrow will reduce
the amount of passing showers over the weekend. This will bring
periods of passing showers and gusty winds across the regional
waters. A fading northerly swell and choppy wind- driven seas will
continue to promote hazardous conditions to small craft. Please
refer to the latest Marine Weather Message (MWWSJU) for detailed
information. Seas are forecast to improve late in the weekend
into early next week.


&&


.BEACH FORECAST...

Dangerous swimming and life-threatening rip currents will continue
through at least Saturday across the east and north-facing
beaches of PR and the USVI, due to rough surf conditions with
breaking waves around 6 feet and higher at times. Given these
conditions, a High Rip Current Risk remains in effect for the
northwest to northeast beaches of the islands. Please refer to the
latest Coastal Hazard Message (CFWSJU) and Surf Zone Forecast
(SRFSJU) for detailed information. Beach goers should remain alert
as a moderate risk of rip currents will continue on Sunday across
across most east and northern beaches of the islands.

&&

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

VI...High Rip Current Risk through Saturday afternoon for VIZ002.

     High Rip Current Risk until 6 PM AST this evening for VIZ001.

AM...Small Craft Advisory until 6 PM AST Saturday for AMZ711-712-741.

     Small Craft Advisory until noon AST Saturday for AMZ716-723-733.

     Small Craft Advisory until 6 AM AST Saturday for AMZ726-742.

&&

$$

CAM/YZR/RC