National Weather Service Today's Weather Impact Levels

740
FXCA62 TJSJ 261840
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
240 PM AST Sun Apr 26 2026

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

.KEY MESSAGES...
Updated at 240 PM AST Sun Apr 26 2026

* Pulses of a small northeasterly swell will continue to create
  life-threatening rip currents along Puerto Rico and the U.S.
  Virgin Islands` north and east-facing beaches through at least
  Tuesday. Please exercise caution along exposed beaches.

* The potential for showers and isolated thunderstorms will
  increase across PR and the USVI from this afternoon through at
  least Tuesday, and possibly beyond, with increased flooding and
  lightning risk.

* A warming trend is likely across PR and USVI, especially at
  urban and coastal sites, as we forecast above- normal
  temperatures through the workweek, with heat indices reaching or
  exceeding 100F, affecting the more vulnerable communities.

&&

.Short Term(This evening through Tuesday)...
Issued at 240 PM AST Sun Apr 26 2026

In general, the US Virgin Islands and Puerto Rico had mostly
clear skies and above-normal temperatures, with maximum
temperatures reaching the low 90s at coastal sites and heat
indices between 98 and 102 degrees Fahrenheit. Some showers moved
across St Croix, St Thomas, and St John early in the morning, and
some were detected downwind from the islands in the form of
streamers early this afternoon. Cloudiness is also increasing
across the interior and northern PR at the moment of writing this
discussion. The winds were calm to light and variable, influenced
by sea breeze variations.

Although this afternoon most of the islands will have mostly
sunny skies under warmer-than-normal temperatures and heat indices
due to the southerly wind flow, showers and isolated
thunderstorms will most likely develop across the interior and
northern sections of PR late this afternoon into the evening, as
well as near the USVI surrounding waters moving inland.
Additionally, later this evening, we cannot rule out additional
rounds of showers and possible isolated thunderstorms affecting
the USVI, and showers in southern windward locations in PR, as
moisture from the Caribbean interacts with a mid- to upper-level
trough lingering over the Northeast Caribbean.

Moisture will continue to increase vertically across the region,
interacting with a mid- to upper-level trough lingering over the
region, which will promote an unstable wet pattern early this
workweek (Monday and Tuesday). The light winds will continue from
the south on Monday, becoming more east-southeast on Tuesday. If
showers and thunderstorms develop, they will slowly move across
the region, potentially increasing the risk of flooding. Please be
aware of the potential for flooding rains across the USVI and PR
each day.

Also, across areas where no rain develops and early in the
afternoon before rain activity, a warming trend is likely, mainly
due (among other factors) to the southerly wind flow and above-
normal sea surface temperatures across the Caribbean waters.

&&

.LONG TERM...(Wednesday through Sunday)...
Issued at 400 AM AST Sun Apr 26 2026

Overall, a moist and unstable weather pattern will persist from
Wednesday through Friday across Puerto Rico and the U.S. Virgin
Islands. Abundant Caribbean moisture, combined with a mid-to-upper-
level trough and an induced surface trough, will support unsettled
conditions through late week. A surface high pressure system over
the central Atlantic will maintain a light to moderate south-
southeasterly wind flow, promoting warm temperatures and high
humidity. A gradual drying trend is expected over the weekend,
allowing for a slight improvement in weather conditions.

From Wednesday through Friday, moisture levels will remain above
normal, with precipitable water (PWAT) values generally ranging
between 1.75 and 2.00 inches. This will support a pattern of daily
showers and isolated thunderstorms, with the most active convection
developing during the afternoon across the interior and northern
portions of Puerto Rico. Morning activity will favor southern and
eastern Puerto Rico as well as the U.S. Virgin Islands, followed by
afternoon convection affecting urban and metropolitan areas. By
Saturday into Sunday, slightly drier air will begin to filter into
the region. Although afternoon showers will still develop, overall
coverage and intensity should decrease compared to earlier in the
period.

Warm conditions will persist throughout the period due to the
prevailing south-southeasterly flow. Temperatures at the 925 mb
level will remain above normal for this time of the year through at
least Friday, gradually easing into the weekend. Maximum surface
temperatures will range from the upper 80s to low 90s across coastal
and urban areas, and from the low to mid-80s in higher terrains.
Combined with high humidity, heat indices are expected to exceed
100F daily, particularly through Friday.

Residents and visitors are encouraged to continue monitoring the
forecast, stay well hydrated, take frequent breaks from the heat,
and limit prolonged sun exposure, especially during peak afternoon
hours.

&&

.AVIATION...
(18Z TAFS)
Issued at 240 PM AST Sun Apr 26 2026

Mainly VFR conditions expected. Light to moderate ESE to SSE flow
over the area can steer -SHRA over windward terminals. Through
around 27/00Z, SHRA/TSRA developing over interior PR can affect
TJSJ/TJBQ, this could result in brief MVFR conditions. Lines of -
SHRA/VCSH can also move over southern and eastern (including USVI)
terminals during the period. ESE to SSE flow up to around 12 kts,
with sea breeze variations, will become light and variable after
26/23z, with land breeze variations, before increasing again to
around 14kts from the SE after around 27/13Z.

&&

.MARINE...
Issued at 240 PM AST Sun Apr 26 2026

The remnants of an old front north of the region will continue as
a surface low enters the northwestern Atlantic. Meanwhile, a
surface high pressure over the central Atlantic will continue to
weaken, as the surface low strengthens during the next few days.
This pattern will promote light to moderate southerly winds
through at least Tuesday, when they will turn more ESE by around
midweek. Pulses of small, long-period NNE swells will continue to
spread across the Atlantic waters and passages through next week.
The possibility of showers and thunderstorms will increase from
this evening through at least the middle of the week.

&&

.BEACH FORECAST...
Issued at 240 PM AST Sun Apr 26 2026

The risk of rip currents is low along the southerly facing
beaches in PR and the USVI. However, we encourage beach
enthusiasts to exercise caution while enjoying the north-facing
beaches from Rincon to Fajardo, and the northern shores of
Culebra, Vieques, St. Croix, St. Thomas, St. John, and nearby
islands, as we occasionally experience northeast swells promoting
the formation of life-threatening rip currents as they break at
the shore. Stay safe!

Keep an eye out for possible afternoon thunderstorms across
portions of PR and the USVI, which could bring strong, gusty
winds and lightning.

&&

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

$$

MORNING CREW....MRR/CAM
EVENING CREW...YZR/MMC

NWS SJU Office Area Forecast Discussion