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FXCA62 TJSJ 300046 AAA
AFDSJU

Area Forecast Discussion...UPDATED
National Weather Service San Juan PR
846 PM AST Sat Jun 29 2024

.UPDATE...Scattered showers continue over the local waters and a
few of these have shown occasional lightning strikes--mainly in
the Mona Channel. Moisture is not likely to diminish before 8 AM
Sunday, but even then, convection is expected to reform over
western and interior PUerto Rico and down stream from the U.S./
Virgin Islands Sunday after noon. Hurricane Beryl continues its
rather rapid motion toward the west. An intermediate bulletin
placed it at 10.2 North and 50.3 west at 8 PM AST. A tropical
wave ahead of it is bringing some thunderstorm activity to the
southern half of the Caribbean south of the forecast area.

&&


.PREV DISCUSSION... /issued 448 PM AST Sat Jun 29 2024/

SYNOPSIS...

A surface high pressure over the central Atlantic will promote
moderate to locally fresh easterly winds over the next few days,
bringing trade wind showers and afternoon convection. Hurricane
Beryl is forecast to strengthen as it approaches the Caribbean
waters late Monday night into Tuesday, deteriorating marine and
coastal conditions considerably for the Caribbean and local
passages. Stay tuned for updates associated with this storm.

SHORT TERM...Tonight through Monday...

A robust surface high remains stretched across the Atlantic Basin
causing a trade wind pattern seasonal pattern to prevail through the
night through Monday, then the movement of Hurricane Beryl south
of the region will cause conditions to deteriorate Monday night.
For now advective showers moving across eastern Puerto Rico and
the USVI will be seen through the morning hours, then followed by
afternoon convection mainly across western Puerto Rico and
downwind of the smaller islands. Flooding is possible across areas
that receive an abundance of showers.

Weather conditions look drier Monday morning and afternoon as a
dry air mass precedes the moisture field of Hurricane Beryl as it
enters the eastern Caribbean Basin on Monday. The region will
effected by subsidence ahead of the storm, which will cause hot
and muggy conditions. This system is currently projected to move
well south of Puerto Rico and the USVI, however windy conditions
and an increase of rainfall Monday night through Tuesday is
forecast. Mainly eastern and southern Puerto Rico will see the
greatest rainfall activity due to the location of the storm,
however do stay alert on the progression of this event to know the
latest track information.

LONG TERM...Tuesday through Saturday...

Tropical activity will dominate much of the long term period with
the presence of Hurricane Beryl and a vigorous tropical wave in
the Eastern Tropical Atlantic.

The National Hurricane Center (NHC) is monitoring Hurricane Beryl
located in the Central Atlantic. Latest model guidance suggest
that Beryl will stay well south of the local islands as a category
2 or 3 hurricane. At this moment, the closest point to Puerto
Rico and the U.S. Virgin Islands will be on Tuesday. Despite this
system staying south of the islands over the Caribbean waters, a
broad field of moisture and external bands could reach the local
area. Therefore, an increase in showers and thunderstorm activity
associated to this system is anticipated. With the expected
conditions, some potential hazards are:
flooding, mudslides, and river rises.

A drier airmass will quickly follow Beryl as it moves away from the
region towards The Hispaniola. This drier airmass will bring some
Saharan Dust particles promoting slightly hazy skies. However,
this dry weather pattern will not last long due to the fast
approach of a tropical wave behind Beryl with the potential of
becoming a tropical cyclone. Model guidance suggest the
development of this wave, and moving this system close to the
local area by Thursday bringING shower activity over the region
and possibly some gusty winds.


Residents and visitors of Puerto Rico and the U.S. Virgin Islands
should continue to monitor the progress of both systems as they
move towards the Caribbean over the next few days.

AVIATION...

(00Z TAFS)

VFR conds will prevail across terminals during the next 24 hrs.
Occasional SHRA/-SHRA will arrive thru the prd mainly alg the N
and E coasts of PR. Hazy skies with P6SM VIS will continue due to
suspended saharan dust particles. TSRA will develop across the
interior/W-PR moving across the surrounding waters thru 30/02z.
Convection will develop tomorrow, btw 30/15z-22z, due to local
effects. Winds will bcm land breezes in easterly flow returning to 15-17
kt with stronger gusts to 25 kt or more near TSRA and sea breeze
variations.

MARINE...

A surface high pressure over the central Atlantic will promote
moderate to locally fresh easterly winds over the next few days,
bringing trade wind showers. Hurricane Beryl is forecast to
strengthen as it approaches the Caribbean waters late Monday night
into Tuesday, deteriorating marine and coastal conditions
considerably for the Caribbean and local passages.

&&

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

&&

$$

SHORT TERM...WS
PUBLIC/UPPER AIR...MMC