414
FXCA62 TJSJ 272056
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
456 PM AST Thu Mar 27 2025

.SYNOPSIS...
A surface trough associated to a cold front now located northwest
of the local region will slowly approach the local area later
tonight. As these features progress, showers are expected to
increase tonight and Friday. This will lead to wetter and windier
conditions, which are forecast to continue through the weekend and
into early part of the next workweek. The increasing winds will
generate high risk of rip currents and hazardous conditions for
small craft operators during the weekend.

&&

.SHORT-TERM...Tonight through Saturday...

Blue skies prevailed during the morning hours across most of Puerto
Rico and the Virgin Islands under a southeasterly wind flow. With
southeasterly winds, temperatures increased, and heat indices ranged
from 90 to around 100 degrees in coastal areas. In the afternoon,
clouds began to develop downwind from the Virgin Islands and
Vieques, and from the Cordillera Central into western Puerto Rico.
Some showers developed too, mostly across the west.

Tomorrow, a surface trough will approach from the east, while a cold
front lies to the northwest. The trough will cause winds to shift
from the east during the day, and from the east-northeast by the
afternoon and early evening hours. These winds will drag a few
showers across east and northeast Puerto Rico, and the Virgin
Islands, with additional showers expected to develop in the west in
the afternoon. Impacts are expected to be limited to wet roads and
accumulation in low-lying areas.


.Long-Term...Sunday through Wednesday...

The long-term forecast remains on track, with a variable weather
pattern. Another broad high surface pressure will move eastward,
pulling the rest of the remnants of the frontal boundary across
the region. Frequent moderate to locally heavy showers will move
along windward sections in the nigh and morning hours and over
western sections of Puerto Rico in the afternoon. Monday is still
anticipated to be the less wet day of the long- term period, but
light to locally moderate showers embedded in the trades will move
occasionally over the CWA. As the high pressure migrates
eastward, breezy winds will turn from the E-ESE late on Monday.
Model guidance suggests that the high pressure and the influence
of a mid low pressure will pool pulses of moisture occasionally
across the region, increasing PWAT values to near above-normal
values (around 1.6 inches). Showers are expected along windward
sections in the morning and western portions of Puerto Rico in the
afternoon. Ponding of water in roadways, urban, and poorly
drained areas is very likely, along with isolated urban flooding.
Temperatures are still expected slightly warmer near above normal
values, however, no significant heat risk is expected.


&&

.AVIATION...
(18Z TAFs)

Prevailing VFR conditions at all TAF sites with VCSH or -SHRA possible
at JBQ through about 27/22. VCSH are expected overnight across USVI
sites and JSJ. Winds from the ESE with local sea breeze variations
will continue at around 10 to 15 kts, becoming more variable and
below 10 kts overnight. Winds will pick up again around 28/13-14Z
to around 12 to 15 kts with higher gusts, and will gradually
become more from the east to northeast.


&&

.MARINE...

A robust surface high pressure system over the Central Atlantic
will promote moderate southeasterly winds today, then turning from the
east tonight. Winds will increase again by Friday night through
the weekend, bringing hazardous conditions for small craft. A cold
front and pre-frontal trough approaching the region will increase shower
and thunderstorm activity starting on Friday.



&&

.BEACH FORECAST...

The risk of rip currents will remain moderate tonight for most
beaches and coastal areas of Puerto Rico and the U.S. Virgin
Islands. However, increasing winds will elevate the risk later on
Saturday for the northern beaches of Puerto Rico, Culebra, and St.
Croix. The risk may remain high for these areas for the next few
days.



&&

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

$$

SHORT TERM...EM
LONG TERM....GRS
AVIATION...EM