284
FXCA62 TJSJ 090717
AFDSJU
Area Forecast Discussion
National Weather Service San Juan PR
317 AM AST Mon Mar 9 2026
...New SHORT TERM, LONG TERM, AVIATION, MARINE, BEACH FORECAST...
.KEY MESSAGES...
Issued at 304 AM AST Mon Mar 9 2026
* Breezy to locally windy conditions will continue across Puerto
Rico and the U.S. Virgin Islands through at least Wednesday.
Unsecured and outdoor objects may blow around.
* Fresh to strong winds will continue to result in choppy to rough
seas and a high risk of rip currents across the region. Small
Craft Advisories and Rip Current Statements continue in effect
through late Tuesday evening.
* Frequent passing trade wind showers are expected to move over
the region for the next few days as patches of moisture
continues to move into the area.
* By Tuesday, showers and thunderstorms activity will increase,
elevating the flooding and lightning potential over Western
Puerto Rico in the afternoon due to the influence of a mid-to-
upper level trough near the area.
&&
.Short Term(Today through Wednesday)...
Issued at 304 AM AST Mon Mar 9 2026
Overnight, bands of showers fueled by a patch of moisture dragged by
the trades moved across the U.S. Virgin Islands, Vieques, Culebra,
and the eastern and southeastern coasts of Puerto Rico. Doppler
radar estimated rainfall accumulations between 0.10 and 0.80 inches,
with the highest totals concentrated over the El Yunque Rainforest,
particularly along the mountain slopes of Naguabo and Ceiba. Across
the U.S. Virgin Islands, accumulations remained below 0.10 inches.
Overnight lows ranged from the low to mid-70s in lower elevations to
the mid and upper 60s across higher terrain. Winds prevailed from
the east at 5 to 15 mph, though the Cyril E. King Airport in St.
Thomas recorded a maximum sustained wind of 23 mph and a gust of 38
mph at approximately 2:15 AM AST during a passing shower.
Weather conditions are expected to remain very similar as in recent
days as a surface high pressure continues to dominate the central
Atlantic. This system will maintain a tight pressure gradient,
promoting fresh to strong easterly winds across the region. By late
Tuesday into Wednesday, as the high migrates toward the eastern
Atlantic, winds will shift more east-northeasterly and gradually
diminish through the end of the workweek.
In the mid-to-upper levels, a trough extending from Jamaica and
eastern Cuba will drift toward Hispaniola by Tuesday through
Wednesday, weakening by Thursday as it moves eastward. Over the
next few days, the influence of this feature, combined with a
persistent upper-level jet and an increase in low-level moisture,
will support instability and periods of enhanced shower activity
and locally heavy rainfall. Precipitable water (PWAT) values will
be near or slightly above seasonal normals (1.5 to 1.75 inches).
Meanwhile, the 500 mb temperatures will remain cool, ranging from
-8C to -10C, further supporting an unstable environment.
Residents and visitors should expect morning showers across
eastern and northern Puerto Rico, Vieques, Culebra, and the U.S.
Virgin Islands, followed by afternoon development over interior
and western Puerto Rico.
&&
.Long Term(Thursday through Monday)...
Issued at 304 AM AST Mon Mar 9 2026
A trough in the mid and upper level will allow for temperatures to
cool down at the mid levels by Thursday. This, along with moderate
moisture content at the lower levels, will result in increasing
showers along eastern Puerto Rico and the Virgin Islands during the
day. However, the heaviest activity is expected for the interior and
west in the afternoon hours. Urban and small stream flooding will be
likely, and there is a medium chance of experiencing thunderstorms
as well. From Friday and into the weekend, strong surface high
pressure centered over the northeastern Atlantic Ocean will steer
the winds from the east-southeast. Speeds will be moderate, around
15 knots for this time period. In the lower levels, patches of
moisture will be dragged in at times. Conditions aloft will not be
as favorable as on Thursday, but in general, the pattern will favor
passing showers across eastern Puerto Rico and the Virgin Islands,
followed by stronger showers in the interior and west each
afternoon. While urban and small stream flooding could occur in
some areas, the most likely scenario is that the showers will lead
to ponding of water in roadways, as well as water surges in creeks
and small rivers. Also, with southeast winds, temperatures will warm
up a little, with highs mostly in the mid and upper 80s for coastal
areas.
&&
.AVIATION...
(06Z TAFS)
Issued at 304 AM AST Mon Mar 9 2026
VFR conds expected across all TAF sites thru the period. Passing
SHRA will result in VCSH at TIST/TISX/TJSJ/TJPS thru 09/14Z. By mid-
morning into the afternoon hours SHRA development will result in -RA
at TJBQ/TJSJ/TJPS thru 09/22-23Z. E winds btwn 15-20 kt with gusts
higher than 30 kt and sea breeze variations aft 09/14Z.
&&
.MARINE...
Issued at 304 AM AST Mon Mar 9 2026
A broad surface high-pressure system extending across the Central
Atlantic will continue to support widespread moderate to fresh trade
winds across the region, resulting in rough seas in local waters.
Recent buoy observations and global model guidance suggest a similar
pattern will persist from Monday into midweek, with wind-driven seas
up to 7 feet and steady easterly winds up to 20 knots, occasionally
producing gusty winds and passing moisture patches. As a result, the
Small Craft Advisory will remain in effect for most of the local
waters. Conditions are expected to gradually improve across the
nearshore waters early in the week; however, choppy conditions will
likely persist across the offshore waters. Small craft operators are
urged to exercise caution and check the latest marine forecasts
before venturing into the local waters.
&&
.BEACH FORECAST...
Issued at 304 AM AST Mon Mar 9 2026
A broad surface high-pressure system over the Central Atlantic,
extending into the Caribbean, will support a tightening of the
pressure gradient across the forecast area. As a result, wind-driven
seas will continue, with seas between 5 and 7 feet across the
Atlantic nearshore waters and the local passages. Therefore, a high
risk of rip currents is expected to persist today across the
northern beaches of Puerto Rico, Culebra, and the U.S. Virgin
Islands. Beachgoers are urged to stay out of the water or exercise
extreme caution. Across the rest of the exposed beaches along the
west, south, and southeast coasts, the rip current risk will remain
moderate, with seas up to 5 feet and winds up to 20 knots, along
with occasional gusty conditions during the day. Improving coastal
conditions are forecast from Tuesday onward as wind-driven seas
gradually diminish across the nearshore coastal waters. For more
detailed information, visit: www.weather.gov/sju/marine.
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk through this afternoon for PRZ001-002-005-
008-012-013.
VI...High Rip Current Risk through this afternoon for VIZ001-002.
AM...Small Craft Advisory until midnight AST Tuesday night for AMZ711.
Small Craft Advisory until midnight AST tonight for AMZ712-716-
726.
Small Craft Advisory until noon AST Tuesday for AMZ723-733-741.
&&
$$
SHORT TERM...GRS
LONG TERM....ERG
MARINE/BEACH...LIS
NWS SJU Office Area Forecast Discussion