National Weather Service Today's Weather Impact Levels

065
FXCA62 TJSJ 220559
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
159 AM AST Fri May 22 2026

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

.KEY MESSAGES...
Issued at 148 AM AST Fri May 22 2026

* Quick-moving passing showers will continue to move across
  windward areas of Puerto Rico and the U.S. Virgin Islands in the
  morning, followed by afternoon showers and isolated
  thunderstorms, particularly across central and northwestern
  Puerto Rico.

* Breezy to locally windy conditions will continue across the
  local islands over the next several days. Keep in mind, gusty
  winds may blow around unsecured items.

* Moderate to locally strong winds will result in choppy to rough
  seas at times, particularly over the offshore waters and a
  moderate rip current risk across most local beaches.

* Warm temperatures will persist each day, with heat indices
  reaching the upper 90s to low 100s. This will primarily affect
  heat-sensitive individuals, especially those outdoors without
  adequate cooling or hydration.

&&

.Short Term(Today through Sunday)...
Issued at 148 AM AST Fri May 22 2026

Scattered showers were observed across the region overnight, mainly
affecting portions of eastern and northeastern Puerto Rico,
including the San Juan metropolitan area. Doppler radar estimated
rainfall accumulations of less than 0.10 inches across these
areas as these showers were moving fast. Passing showers were also
observed brushing the southern coast of Puerto Rico and the U.S.
Virgin Islands; however, most of the activity remained over the
waters. Overnight lows ranged from the low to mid-70s across
coastal and urban areas, and from the low to mid-60s in the higher
elevations. East- southeast winds prevailed at 5 to 10 mph, with
occasional higher gusts and land breeze variations.

A mid-level ridge building over the region is expected to bring
relatively stable conditions aloft. At the surface, a strengthening
high pressure system over the central Atlantic is tightening the
local pressure gradient and will continue to promote moderate to
fresh, and locally strong, east-southeasterly winds. This pattern is
expected to persist through the weekend. Therefore, under these
conditions, unsecured items could blow around.

Today, a patch of shallow moisture with precipitable water (PWAT)
values of 1.75 to 1.80 inches will continue to filter into the area
during the morning hours, bringing additional showers to the
islands. However, as the day progresses, relatively drier air with
PWAT values of 1.45 to 1.60 inches will begin to filter into the
area, diminishing shower activity. Nonetheless, despite this
expected weather scenario, daytime heating and local effects
combined with the available moisture will support the development of
isolated to scattered showers across northwestern Puerto Rico. Lines
of showers streaming off the islands are also anticipated to form in
the afternoon hours, including the El Yunque streamer, which could
affect the San Juan metropolitan area and adjacent municipalities. A
similar pattern is expected to persist on Saturday and Sunday with
slightly higher moisture levels, which could lead to an increase in
showers across the region and enhanced afternoon convective
activity, particularly on Sunday. Breezy conditions should keep
showers moving quickly, limiting the potential for significant
flooding. The U.S. Virgin Islands will observe mainly fair weather
conditions during the short-term period, with quick-moving showers
confined mainly to the morning hours.

Warm seasonal temperatures will persist each day through early next
week, particularly across coastal and urban areas. Maximum
temperatures are expected to range from the upper 80s to low 90s
along coastal areas, and from the low to mid-80s in the higher
elevations. Heat indices will rise between 100 and 105 degrees
Fahrenheit. Residents and visitors are urged to stay hydrated, seek
shade, and monitor local conditions to ensure safety during peak
heating hours.

&&

.Long Term(Monday through Friday)...
Issued at 148 AM AST Fri May 22 2026

Variable conditions are still expected in the long-term forecast,
with Tuesday and Wednesday being the most unstable. A broad surface
high pressure over the western Atlantic is expected to extend into
the Central Atlantic, with winds shifting from the E-SE through most
of the period. Strengthening winds will bring breezy conditions
throughout the long-term forecast, with Monday the windiest day.
Although a mid-level ridge is expected to build over the Western
Atlantic, troughiness associated with an upper-level trough will
maintain slight instability across the CWA. The latest model
guidance solutions continue to suggest an increase in moisture
content in the region, with the latest solution showing PWAT values
near to above normal (between 1.8 and 2.0 inches, with a low chance
of reaching 2.2 inches). Additionally, low to mid-level moisture
should ascend to well above climatological normal (60 - 80%), with
model soundings suggesting skinny profiles. In terms of instability,
deep convection is expected across the region, particularly during
the afternoons and evenings, as mid-level temperatures should remain
cool (between -7 and -8 degrees Celsius), while guidance shows
signals of enhanced vorticity on Tuesday and Wednesday. These
conditions combined with local effect and daytime heating should
allow deeper convection activity. For each day, expect passing
showers moving over windward sections of the islands throughout
the day, with afternoon convection over interior and western to
northwestern Puerto Rico. Additionally, island streamers could
move over eastern Puerto Rico, including the San Juan Metro Area,
increasing flooding potential. Due to fast-moving showers,
rainfall accumulations should remain limited, resulting in ponding
of water across roadways and poorly drained areas and minor
flooding over the aforementioned areas. However, urban and small
stream over localized areas cannot be ruled out. In addition to
flooding, hazards such as gusty winds and lightning can be
expected during periods of heavy showers. Weather conditions
should gradually improve by the end of the period.

In terms of heat, model guidance continues to suggest temperatures
typical for this time of the year. However, combined with available
moisture, localized urban and coastal areas of the islands may
experience heat indices reaching 100 degrees Fahrenheit. Although
the risk will remain limited, individuals sensitive to heat should
take the necessary precautions.

&&

.AVIATION...
(06Z TAFS)
Issued at 148 AM AST Fri May 22 2026

VFR conds across all TAF sites. Breezy to locally windy, E to SE
winds up to 15-20 kts after 22/14Z, with higher gusts and sea
breeze variations, decreasing aft 22/23Z. Aftn SHRA/+SHRA and
VCTS, will develop across the interior and NW PR, and downwind
from El Yunque possibly resulting in brief MVFR/IFR conds over
TJBQ/TJSJ btwn 22/17-21Z. Winds will bring periods of -SHRA/VCSH
around TJPS/TISX/TIST thru 22/23Z.


&&

.MARINE...
Issued at 148 AM AST Fri May 22 2026

Moderate to fresh easterly winds will continue across the regional
waters through the next several days due to strong high pressure
over the Atlantic. Choppy to rough seas will persist at times and
small craft should exercise caution, especially across the offshore
Atlantic waters. Isolated afternoon thunderstorms may develop near
the western coastal waters of Puerto Rico, producing locally higher
winds and seas.

&&

.BEACH FORECAST...
Issued at 148 AM AST Fri May 22 2026

A moderate risk of rip currents will persist across most local
beaches through the next several days due to persistent breezy
conditions and wind-driven seas. The highest risk will continue
along north- and east-facing beaches. Life-threatening rip currents
remain possible.

&&

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

$$

SHORT TERM...GRS
LONG TERM....MNG
MARINE/BEACH FORECAST...ICP

NWS SJU Office Area Forecast Discussion