Atlantic Hurricane Season 2025 Storm Names

042
FXCA62 TJSJ 231857
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
257 PM AST Mon Jun 23 2025

.KEY MESSAGES...

* A tropical wave moving away south of the region will maintain
  shower and thunderstorm activity tonight, gradually improving
  into tomorrow.

* Moderate concentrations of Saharan Dust are expected mainly
  tomorrow and Thursday, with a slightly decrease in concentrations
  during Wednesday. Hazy skies and poor air quality are expected.

* Daily afternoon showers and isolated thunderstorms are expected,
  particularly over western Puerto Rico due to local effects.

* By the end of the week into the weekend, a TUTT-low is forecast
  to develop just north/northeast of the region, and another
  tropical wave is expected to enter the eastern Caribbean.

&&

.SHORT TERM...Tonight through Wednesday...

Variable weather conditions under partly to mostly cloudy skies
prevailed across the forecast area this morning, influenced by a
tropical wave that has entered the eastern Caribbean, with its
axis moving south of the islands. Due to this tropical wave, the
latest model guidance suggests above-normal PWAT values exceeding
1.65 inches, and locally reaching up to 2.00 inches. Passing
showers affected the eastern half of Puerto Rico earlier in the
day. By midday, stronger showers developed, mainly over the
northwestern quadrant of the island. Radar estimates indicated
maximum rainfall accumulations of about 1 to 1.3 inches in Moca
and along the coast of Aguada. These showers dissipated before 2
PM AST. In terms of winds, breezy to locally windy conditions
persisted, with weather stations reporting gusts up to 30 mph at
San Juan International Airport, Cabo Rojo, and St. Croix; 31 mph
in St. Thomas; and 33 mph at Ponces Mercedita Airport, among
other locations.

For the remainder of the afternoon, some showers are expected to
continue across western sectors of Puerto Rico. Tonight, models
suggest the arrival of additional showers across eastern Puerto
Rico, Vieques, and Culebra, with rain chances ranging from 30 to
60 percent in those areas, and 10 to 20 percent elsewhere.

By Tuesday and Wednesday, following the passage of the tropical
wave, drier air will filter into the region. This will lead to
fewer and more localized afternoon showers and isolated thunderstorms,
mainly driven by local effects. The flood threat will remain from
none to limited, primarily for western Puerto Rico. A key topic
for tomorrow will be the arrival of a moderate Saharan Air Layer.
As a result, hazy skies, reduced visibilities, and poor air
quality are likely. Normal to above-normal temperatures will also
continue over the next several days, with 925 mb temperatures
reaching the upper 80s to lower 90s in coastal and urban areas,
and the upper 70s to low 80s in higher elevations. Fewer clouds
and limited rain will contribute to an elevated heat risk. Please
stay alert for any forecast updates and the possible issuance of a
Heat Advisoryespecially for heat- sensitive individuals, including
those without adequate cooling or hydration. By Wednesday, rainfall
is expected to remain limited. Although Saharan dust concentrations
will slightly decrease, hazy skies and warm temperatures will persist.

.LONG TERM...Thursday through Monday...
.PREV DISCUSSION... /issued 449 AM AST Mon Jun 23 2025/

A broad surface high pressure extending from the central Atlantic
and a strong 850-700mb ridge moving just north of the region will
continue to promote breezy conditions and drier air intrusion
through early Friday. A weak Saharan Air Layer is expected to
linger through Thursday over the region, promoting hazy skies.
Fair weather conditions are expected in general across the
islands on Thursday, with the exception of afternoon showers and
isolated thunderstorms developing over western Puerto Rico due to
diurnal and local effects. By late Friday into Saturday, a TUTT-
low is forecast to develop just north/northeast of the region.
An induced surface trough is expected to cross the region during
this period, and winds will shift from the ENE, promoting
afternoon shower development mainly over the SW quadrant of Puerto
Rico. Across the the U.S. Virgin Islands and eastern Puerto Rico,
showers are expected to increase mainly during the night.

Lingering moisture on Saturday and ESE winds behind the trough
passage will aid in the development of afternoon showers and
thunderstorms once again over the NW quadrant of PR, and downwind
from el Yunque. A tropical wave is expected to follow quickly and
enter the eastern Caribbean between late Saturday and Sunday
morning. Increasing the areal coverage of showers and thunderstorms
once again across portions of the islands and local waters.

&&

.AVIATION...
(18Z TAFs)

VFR conditions are mainly expected during this forecast period.
VCSH are expected across TJSJ and USVI TAF sites tonight and
during the morning hours. Tomorrow, VCTS are possible after 24/17Z
across TJBQ with possible brief MVFR conditions. The main aviation
concern tomorrow onward will be the arrival of a Saharan Air Layer,
as a result reduced visibilities are likely over the next few days.

&&

.MARINE...

A subtropical Atlantic ridge extending southward into the northern
Caribbean continues to promote moderate to locally fresh easterly
winds, resulting in choppy seas across portions of the local
Atlantic and Caribbean waters, as well as the local passages.
Therefore, small craft should exercise caution across most waters.
A tropical wave moving across the Caribbean Sea will continue to
produce isolated to scattered showers and thunderstorms over the
local waters tonight, with conditions gradually improving into
tomorrow.

&&

.BEACH FORECAST...

Wave heights of around 3 to 4 feet and a moderate risk of rip
currents are expected tonight along most beaches of Puerto Rico,
including Vieques, Culebra, and the U.S. Virgin Islands. A
moderate risk indicates that life-threatening rip currents are
possible in the surf zone. As a result, beachgoers are encouraged
to exercise caution, especially during the upcoming festivities.

&&

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

$$

SHORT TERM/AVIATION...YZR/MRR
LONG TERM...DS

NWS SJU Office Area Forecast Discussion