Your Number One Source for Real-Time Puerto Rico Weather & Hurricane Tracking Updates

162
FXCA62 TJSJ 300737
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
337 AM AST Thu Apr 30 2026

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

.KEY MESSAGES...
Updated at 330 AM AST Thu Apr 30 2026

* An elevated flooding risk is expected today for portions of the
  interior, northern and northwestern Puerto Rico as strong
  showers and thunderstorms develop during the afternoon hours.
  Soils are already saturated from previous rains and elevated
  river levels may worsen impacts in vulnerable areas.

* Across the U.S. Virgin Islands, mainly fair weather conditions
  will prevail with few passing showers moving into the area from
  time to time.

* A gradual transition into drier and stable conditions is
  expected to from late Friday onward, as a high-pressure system
  strengthens to the north and a mid-level ridge builds over the
  region.

* Warmer-than-normal temperatures will continue through the
  weekend, with heat indices reaching or exceeding 100F across
  urban and coastal areas.

* A moderate rip current risk will continue for north- and east-
  facing beaches of the islands. Beachgoers should exercise caution
  along exposed beaches.

&&

.Short Term(Today through Saturday)...
Issued at 330 AM AST Thu Apr 30 2026

Calm conditions prevailed across the islands overnight; however,
Doppler radar and satellite imagery detected persistent shower bands
over the offshore Atlantic waters and the Mona Channel, northwest of
Aguadilla. While some of these showers brushed the coastline, the
rest of the region experienced mostly clear to partly cloudy skies.
Overnight minimum temperatures ranged from the mid-70s in coastal
and urban areas to the low-to-mid 60s across the mountains, with
light and variable winds remaining at 5 knots or less.

Another day of wet and unsettled weather is expected as abundant
moisture, with precipitable water (PWAT) values up to 2.25 inches,
moves over the islands. With winds remaining light and variable,
conditions are favorable for another round of afternoon convective
activity across central, northern, and western Puerto Rico,
including the San Juan metropolitan area. Moderate to heavy rainfall
and thunderstorms are likely across these areas, fueled by daytime
heating, local effects, and instability aloft.

Given the slow-moving nature of these storms, the risk of flooding
will remain elevated through Friday. Heavy rainfall, frequent
lightning, and gusty winds are expected, which may lead to rapid
river rises and minor urban flooding. Because soils are already
saturated from previous rainfall, landslides cannot be ruled out,
particularly across the central municipalities of Puerto Rico.
Meanwhile, the U.S. Virgin Islands will likely see only passing
morning showers with minimal impacts.

A gradual transition toward drier, more stable conditions is
anticipated late Friday into Saturday as a high-pressure system
strengthens to the north and a mid-level ridge builds over the
region. Warm to hot temperatures will persist throughout the
weekend, especially across coastal and urban areas, where heat
indices are forecast to reach or exceed 100F each day.

&&

.Long Term(Sunday through Thursday)...
Issued at 330 AM AST Thu Apr 30 2026

The long-term period will be dominated by generally tranquil, near-
seasonal conditions for both Puerto Rico and the U.S. Virgin
Islands. Surface high pressure over the central Atlantic will
promote east to southeast winds at 8 to 15 mph through the period.
Aloft, a ridging pattern will persist, supporting stable conditions.
On Sunday, patches of moisture will maintain precipitable water
(PWAT) values near seasonal levels, around 1.5 inches. This will
support brief, passing showers across windward areas during the
morning, followed by scattered afternoon showers and isolated
thunderstorms across the northwestern quadrant of Puerto Rico. Flood
risk will remain low and localized.

A drying trend will develop early next week, leading to improving
conditions. Model guidance indicates PWAT values falling into the
25th percentile. In perspective, PWAT values are expected to be
around 1.25 inches or less. Combined with a mid to upper-level
ridge, this will enhance stability. The driest period is expected
from Monday through Wednesday. Afternoon showers may still develop
due to local effects and diurnal heating, but coverage will be
limited and activity brief. Rain chances will range from 10 to 30
percent each afternoon across northwestern Puerto Rico. By Thursday,
moisture will increase back to near-normal levels as patches of
moisture arrive. At the same time, an upper-level trough will begin
to amplify into the region, increasing instability and the potential
for shower development.

Despite reduced rainfall, the main hazard will be the warm
conditions that will likely persist across the islands. Temperature
guidance at 925 mb, along with a prevailing east to southeasterly
wind flow, suggests values will remain above normal throughout the
forecast period. Daytime highs will range from the upper 80s to low
90s in coastal and urban areas, and from the upper 70s to mid-80s in
higher elevations. Heat indices will reach the upper 90s to low 100s
degrees F daily. A limited heat threat will persist for urban,
coastal, and low-elevation areas. Residents and visitors should stay
hydrated and limit prolonged sun exposure during peak heating
hours.

&&

.AVIATION...
(06Z TAFS)
Issued at 330 AM AST Thu Apr 30 2026

Mainly VFR conds will likely continue across most TAF sites. Wet and
unstable conditions will persist today, bringing rounds of SHRA/TSRA
during the aftn hours. This activity will result in brief MVFR/IFR
conds with VCTS for TJSJ/TJPS/TJBQ thru 30/23Z. Light/variable winds
early in the morning, becoming E-SE btw 8-12 kt after 30/14Z. Winds
will turn light/variable by 30/23Z thru 01/14Z.

&&

.MARINE...
Issued at 330 AM AST Thu Apr 30 2026

A series of highs and frontal lows over the western to central
Atlantic will prevail over the next few days. Winds will become more
east- southeasterly today and east to east southeasterly on Friday.
Moisture over the region and a nearby trough will continue to result
in showers and isolated t-storms over the next few days,
particularly during the afternoon hours. Pulses of small, long-
period northerly swell will continue to spread across the Atlantic
waters and local passages through this evening, though seas should
remain between 2 to 4 feet. Periods of another weak but long-period
northerly swell will reach the Atlantic waters by early Saturday.

&&

.BEACH FORECAST...
Issued at 330 AM AST Thu Apr 30 2026

The moderate risk of rip currents will continue for north- and east-
facing beaches of the Puerto Rico due to pulses of a small, long-
period northeasterly swell. Intermittent periods of  moderate to low
risk of rip current for the rest of the islands. Life-threatening
rip currents remain possible in the surf zone. A low risk of rip
currents will persist elsewhere, though isolated stronger currents
may develop near piers, jetties, reefs, and channels. Beachgoers
should exercise caution and monitor the weather, as showers and
thunderstorms may affect coastal areas at times through Friday.

For additional information and location-specific rip current
details, please visit weather.gov/beach/sju.

&&

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

$$

SHORT TERM...GRS
LONG TERM....YZR
MARINE/BEACH...MMC

NWS SJU Office Area Forecast Discussion