717
FXCA62 TJSJ 120800
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
400 AM AST Thu Jun 12 2025

KEY MESSAGES...

* Breezy to windy conditions will support a moderate risk of life-
  threatening rip currents, choppy seas, and may blow unsecured
  objects, creating hazards for swimmers, small boats, and
  property.

* Elevated fire danger is expected today and will likely extend
  through Saturday, increasing wildfire riskespecially in
  southern Puerto Rico. Please avoid outdoor burning and stay
  alert.

* Moderate to high concentrations of Saharan dust will maintain
  reduced visibility and air quality through Friday, potentially
  affecting those with respiratory sensitivities.

* Showers and isolated thunderstorms development is likely every
  day, with flooding risks increasing from Sunday through Tuesday,
  posing threats to life and property.


&&

.SHORT TERM...Today through Saturday...

A quiet night was observed across Puerto Rico and the U.S. Virgin
Islands. Satellite and radar imagery registered limited, fast-moving
showers over the surrounding waters, with just a few spotty showers
reaching portions of eastern Puerto Rico, resulting in very low
rainfall accumulations. Breezy to locally windy conditions persisted
across coastal areas and nearby waters. Surface weather stations and
buoys across southeastern Puerto Rico, near San Juan, between
Vieques and Culebra, and throughout the USVI recorded maximum wind
gusts ranging from 20 to nearly 30 mph during the overnight period.
Temperatures ranged from the mid to upper 60s in the higher
elevations of the Cordillera Central to mainly the mid-70s to around
80F along coastal areas.

A broad surface high-pressure system over the central Atlantic will
continue to support breezy to locally windy east-southeast winds.
Aloft, the upper-level trough to the east will continue drifting
into the central Atlantic basin, while a mid-level ridge will
dominate from the northwest. As anticipated, starting today, a drier
air mass will enter the area, extending into the mid to upper levels
of the atmosphere. The latest models suggest precipitable water
(PWAT) values will remain below 1.6 inches through at least next
Saturday, which is considered below average values for this time of
the year. In addition, moderate to locally high concentrations of
Saharan dust will persist over the region through at least Friday
morning.

As a result, in terms of rainfall, weather conditions will continue
to improve throughout the forecast period. However, local effects
and diurnal heating, combined with the available low-level moisture,
will enhance afternoon convection each day, with isolated showers
and thunderstorms expected across western Puerto Rico. The flood
risk for today and the next two days remains limitedmainly across
the far western corner of Puerto Rico during the afternoon hours.
This could lead to ponding of water on roads and in poorly drained
areas. There is a low chance of urban and small stream flooding.

Keep in mind that the presence of Saharan dust and limited rain
activity may cause temperatures to feel warmer than usual. A limited
heat risk will persist each day across the urban and coastal areas
of the islands. This level of heat primarily affects individuals who
are highly sensitive, especially those spending time outdoors
without adequate cooling or proper hydration. Temperatures will
range from the upper 80s to low 90s in lower elevations and coastal
areas, with heat indices exceeding 100F. Please take necessary
precautions and remember to stay hydrated.

Overall, breezy conditions, the presence of Saharan dust, and
limited rainfall will persist. However, locally induced convection
is likely to develop daily across western Puerto Rico, with a few
short-lived thunderstorms possible and a limited heat risk
continuing across coastal and urban areas.

.LONG TERM...Sunday through Thursday...

Long-term guidance remains mostly unchanged, with minor
adjustments reflecting a later and shorter southward dip of the
upper-level trough. This trough is expected to deepen and form a
closed low northwest of the region by Sunday, shifting west early
next week before moving away by midweek. This will increase
atmospheric instability by cooling mid-level temperatures,
weakening the trade wind cap inversion, and increasing the amount
of moisture. As a result, precipitable water values are forecast
to rise above 2.0 inchesabove normal for this time of yearwith
Sunday and Monday likely being the wettest days. Moisture levels
are expected to return to near normal (1.6 to 1.9 inches) for the
remainder of the week.

At the surface, a broad high-pressure system will maintain
moderate to locally fresh easterly winds, producing breezy to
locally windy conditions, especially along the coast and exposed
areas. Temperatures will be slightly cooler Sunday through
Tuesday, then trend warmer from Wednesday onward due to higher
low-level temperatures, decreased cloud cover, and reduced
rainfall chances.

Rainfall is expected to increase from Sunday through Tuesday as
deeper moisture and instability support more organized afternoon
showers and isolated thunderstorms, primarily over central,
western, and northern Puerto Rico, including parts of the San Juan
metropolitan area. Meanwhile, breezy trade winds will bring
frequent showers overnight and early morning to eastern Puerto
Rico and the U.S. Virgin Islands. Urban and small stream flooding,
along with localized flash flooding, is possible in areas with
heavier or prolonged rain. A return to a more typical shower
pattern is expected later in the week, depending on how far the
upper-level trough sinks into the Caribbean before moving away.

Overall, hazards such as excessive heat, gusty winds, and
lightning will remain at limited risk levels; however, the risk
of excessive rainfall and localized flooding will increase,
especially from Sunday through at least Tuesday.


&&

.AVIATION...
(06Z TAFs)

Mainly VFR conditions expected to prevail through the period with
drier airmass across the region. SHRA to -RA are expected after 18Z
across western Puerto Rico and some may reach portions of the
vicinity of TJBQ at times. Brief periods of reduced VIS and low
ceilings possible. Additionally, Saharan dust expected to result in
hazy skies with VIS at 5-8SM. Breezy to locally windy conditions
will continue today after 13Z. Sea breeze variations and maximum
gusts nearly 28 to 30 knots. Slightly lighter winds overnight.

&&

.MARINE...

A broad surface high pressure over the North Atlantic will
continue to generate moderate to locally fresh easterly winds,
causing choppy seas across most local waters and Caribbean
passages. Small craft operators should remain cautious. These
conditions are expected to persist through the rest of the
workweek and into the weekend. Isolated afternoon thunderstorms
may develop daily, mainly over the northern and western coastal
waters of Puerto Rico. Thunderstorm activity is likely to increase
by the end of the weekend into early next week.


&&

.BEACH FORECAST...

Breezy to locally windy conditions are expected today,
maintaining a moderate risk of life-threatening rip currents along
most local beaches, especially in exposed coastal areas. Non-
exposed western beaches will have a lower risk, though isolated
stronger currents may still develop near piers, jetties, and
channels. Morning showers are likely across eastern Puerto Rico,
followed by isolated afternoon thunderstorms in northern and
western coastal areas. This moderate rip current risk is expected
to persist over the next few days, with some beaches briefly
transitioning to a low risk. Looking ahead, a high rip current
risk is possible early next week for St. Croix. Beachgoers should
swim near lifeguards, avoid strong currents, and remain vigilant
for gusty winds and changing weather conditions. For the latest
information, please refer to the Surf Zone Forecast (SRFSJU).


&&

.FIRE WEATHER...

Southern Puerto Rico remains very dry, with high KBDI values and
significant rainfall deficits over the past 3060 days. Todays
breezy to locally windy conditions combined with low humidity
increases the risk of fire spread. Fire danger has been briefly
elevated recently, but a prolonged period of elevated fire danger
is expected today, prompting a Fire Danger Statement for southern
Puerto Rico. For details on todays fire danger risk and expected
conditions, please see the Fire Danger Statement (RFDSJU).

The ongoing drying trend and extended periods of elevated fire
danger remain a serious concern. Breezy to windy conditions and
continued drying are expected through Friday and Saturday.


&&

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

$$

SHORT TERM...YZR
LONG TERM....ICP
AVIATION...YZR