National Weather Service Today's Weather Impact Levels

915
FXCA62 TJSJ 140809
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
409 AM AST Thu May 14 2026

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

.KEY MESSAGES...
Issued at 313 AM AST Thu May 14 2026

 * Dangerous heat conditions will continue through the weekend
   across urban and coastal areas of Puerto Rico and the U.S.
   Virgin Islands, with heat indices exceeding 100F at times.
   Additional Heat Advisories may be required.

 * East to east-southeasterly winds will continue to bring
   periods of passing showers across the US Virgin Islands and
   PR`s windward areas, especially overnight and during the
   morning hours, followed by afternoon convection across interior
   and western Puerto Rico each day. Localized ponding of water
   and isolated urban and small stream flooding will remain
   possible.

 * A wetter and slightly more unstable weather pattern may develop
   early next week as an upper-level trough approaches the
   region, increasing the potential for more frequent showers and
   isolated thunderstorms.

 * A northeasterly swell combined with locally generated wind
   waves will maintain a high risk of dangerous rip currents along
   portions of the north and east-facing beaches of Puerto Rico
   and the US Virgin Islands.

 * Traces of Saharan dust particles are expected between Friday
   and Saturday. Although the highest concentrations should remain
   south of the islands, hazy skies and minor air quality
   reductions will still be possible.

&&

.Short Term(Today through Saturday)...
Issued at 313 AM AST Thu May 14 2026

A surge of moisture caused showery weather across the local
waters, the USVI, and south and east PR overnight, moving further
inland under the east-southeast winds. Low temperatures ranged
from the mid-70s to the low-80s at urban and coastal sites, to the
mid- and upper-60s at mountain sites. Once again, the winds were
mainly from the east to east-southeast at 10 to 15 mph, with
higher gusts across windward locations, and light to calm and
variable across leeward sites, where land breeze fluctuations were
also noted.

In general, a surge of moisture brought fast-moving showers
across the local waters, the USVI, and south and east PR, moving
further inland under the east-southeast winds. Low temperatures
ranged from the mid-70s to the low-80s at urban and coastal sites,
to the mid- and upper-60s at mountain sites. The winds were
mainly from the east to east-southeast at 10 to 15 mph, with
higher gusts across windward locations, and 5 to 10 across leeward
sites, where land breeze fluctuations were also noted.

Although periods of increased moisture will bring occasional
showers across portions of Puerto Rico and the U.S. Virgin
Islands, especially in windward areas, areas without rainfall will
continue to experience dangerously hot conditions. Heat indices
are expected to reach values up to 111F in urban and coastal
areas. As a result, a Heat Advisory remains in effect from 10 AM
to 4 PM AST for portions of Puerto Rico and the U.S. Virgin
Islands. These conditions can be dangerous, particularly for
people sensitive to heat, those without adequate hydration or
cooling, outdoor workers, and vulnerable populations. Heat stress
may also impact some healthcare systems and heat-sensitive
industries. Warm to hot conditions are expected to continue
through the weekend, and additional Heat Advisories may become
necessary.

Meanwhile, east to southeast winds will continue to move patches
of moisture across Puerto Rico and the U.S. Virgin Islands,
resulting in periods of showery weather each day, especially
during the overnight and morning hours across windward areas. At
times, local effects, low-level convergence, and terrain
influences may enhance rainfall, leading to periods of moderate to
locally heavy rain. Ponding of water on roads, reduced
visibility, and isolated urban and small stream flooding will
remain possible through the forecast period.

In the afternoons, daytime heating, sea breeze convergence, local
terrain effects, and available moisture will support the
development of showers and possibly isolated thunderstorms across
the interior and western sections of Puerto Rico. A limited risk
of flooding will also persist in these areas each day.

Traces of Saharan dust particles are also expected to arrive
across the region, especially between Friday and Saturday.
However, the latest model guidance suggests that the highest
concentrations will remain farther south across the Caribbean Sea,
limiting impacts across the local islands. Even so, hazy skies and
minor reductions in air quality and visibility will still be
possible at times.

&&

.Long Term(Sunday through Thursday)...
Issued at 313 AM AST Thu May 14 2026

The inherited forecast remains on track, with Sunday expected to be
the driest and most stable day of the long-term period. Residual
concentrations of Saharan Air Layer (SAL) dust will linger mainly
south of the islands through Sunday, according to the latest Dust
model guidance. Although relatively drier and more stable conditions
are anticipated, available low-level moisture and local effects will
still promote periods of passing showers, particularly during the
overnight and morning hours across eastern Puerto Rico and the U.S.
Virgin Islands. Afternoon shallow convection is expected across
western Puerto Rico.

Beginning Monday, moisture and instability will gradually increase
across the region as an upper-level trough amplifies over the
northeastern Caribbean and potentially evolves into a cut-off low
near the Bahamas by midweek. Latest model guidance indicates 250 mb
heights gradually lowering starting Monday, while 500 mb
temperatures cool to around -7 to -8 degrees Celsius from Tuesday
through Thursday. At the same time, precipitable water (PWAT) values
are forecast to remain near climatological normals initially before
gradually increasing. As deeper tropical moisture spreads across the
islands during the first half of the workweek, shower coverage and
frequency are expected to increase. By Wednesday and beyond, the
combination of higher moisture content and cooler temperatures aloft
will support the most unstable conditions of the forecast period.
This pattern will favor more organized afternoon convection with
isolated to scattered thunderstorms across western and northwestern
Puerto Rico, with activity potentially extending into portions of
the San Juan Metropolitan Area. Periods of locally heavy rainfall
may result in minor urban and small-stream flooding, particularly in
windward and urban areas. Overall, active weather is anticipated
during the afternoon hours through much of the long-term forecast
period.

Temperatures are expected to remain warm throughout the period as
southeasterly winds persist across the region. Combined with
increasing moisture, heat indices will likely exceed 100 degrees
Fahrenheit across lower elevations and urban areas, resulting in a
limited to locally elevated heat risk each day. Residents and
visitors should continue to monitor future forecasts, as Heat
Advisory issuances may become necessary.

&&

.AVIATION...
(06Z TAFS)
Issued at 313 AM AST Thu May 14 2026

In general we expect VFR conditions to prevail through much of the
forecast period. However, occasional fast-moving SHRA/-SHRA will
arrive embedded in the E-ESE wind flow, moving across windward
terminals. Additional SHRA/+SHRA will form across the interior and
NW-PR btwn 14/16-23z, probably affecting JBQ and JSJ, which could
cause brief MVFR or IFR conds. Winds will prevail from the E-ESE
at 5-15 kt, then aft 14/13z winds will range btwn 15-20kt with
higher gusts and sea breeze variations.

&&

.MARINE...
Issued at 313 AM AST Thu May 14 2026

A broad surface high-pressure over the central Atlantic will
continue to promote moderate to locally fresh east to east-
southeasterly winds across the regional waters. These breezy
conditions will maintain somewhat choppy seas, particularly across
the offshore and exposed Atlantic and Caribbean waters. Today, a
weak long-period northeasterly swell will continue to spread across
the local Atlantic waters, with associated wave heights around 3
feet. However, this swell is expected to have only a limited impact
on local marine conditions. As a result, seas are forecast to remain
between 4 and 5 feet, occasionally up to 6 feet, through at least
the upcoming weekend.

&&

.BEACH FORECAST...
Issued at 313 AM AST Thu May 14 2026

Breezy east to east-southeasterly winds will continue across the
regional waters through at least today, maintaining choppy surf
conditions along many local beaches, particularly across the north
and east-facing coastlines. A weak long-period northeasterly
swell will continue spreading across the local Atlantic waters
today. This swell, combined with locally generated wind waves,
will significantly enhance the risk of dangerous rip currents.

Therefore, a High Rip Current Risk Statement has been issued for
beaches along the northwestern to northeastern coast of Puerto
Rico and the US Virgin Islands through this evening. Beachgoers
are strongly urged to swim only at beaches with lifeguards on
duty, remain aware of changing surf conditions, and avoid
venturing too far from shore.

For additional information, visit weather.gov/beach/sju.

&&

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

     Heat Advisory from 11 AM this morning to 4 PM AST this afternoon
     for PRZ001>003-005-007-008-010>013.

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

     Heat Advisory from 11 AM this morning to 4 PM AST this afternoon
     for VIZ001-002.

AM...None.
&&

$$

KEY MESSAGES/SHORT TERM/AVIATION...CAM
MARINE/BEACH FORECAST....CVB LONG TERM...MMC

NWS SJU Office Area Forecast Discussion