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000
FXCA62 TJSJ 192039
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
439 PM AST Fri Apr 19 2024

.SYNOPSIS...

Unsettled weather conditions will continue to linger across the
region, with the potential for flooding and mudslides across the
central interior and portions of eastern Puerto Rico everyday. Dry
air is expected to filter into the islands, however due to daytime
heating and local effects the shower activity with isolated
thunderstorms is anticipated. By early next week, temperature will
increase as winds shifts from the east to southeast.

&&

.SHORT TERM...Tonight through Sunday...

Partly cloudy skies prevailed during the morning hours across the
islands. Today, the afternoon convection started around noon along
the Cordillera Central. Heavy showers with isolated thunderstorms
were observed, once again, over municipalities affected with rains
in the past few days. Flood advisories were issued from San German
towards San Lorenzo, and from Carolina to Las Piedras. Rainfall
accumulations ranged between 1 to 3 inches across these areas. The
municipality of Yauco registered up to 3.5 inches of rain. Winds
were light and from the east northeast with higher gusts embedded
in the heaviest showers. The island of St. Croix also observed
shower activity with accumulations around 0.5 inches in the
southwest corner.

The rainfall activity is expected to linger across Puerto Rico until
the early evening hours. Additional accumulations are anticipated
over the southern and east central municipalities. Conditions will
gradually improve as the night progresses. By Saturday, another
active day is expected due to daytime heating and local effects,
across the Cordillera Central with the potential of heavy showers
and isolated thunderstorms. Therefore, there is an elevated
potential for flooding of urban areas, roads and small streams.
Mudslides are also expected due to saturated soils across the
central interior.

A building high pressure moving from the western to central Atlantic
will promote light winds from the east northeast until Saturday
night. Then, winds are expected to veer from the east southeast by
Sunday onward. On Sunday, a similar weather pattern is forecast with
the higher potential for rains across the central and western
portions of Puerto Rico. Across the U.S. Virgin Islands, mainly fair
weather conditions are expected, with light passing showers
affecting during the overnight hours. For the rest of the weekend,
temperatures will remain in the mid to upper 80s across much of
the islands, with heat indices in the mid to upper 90s.

For everyone attending the Hurricane Hunters Visit in Aguadilla,
Puerto Rico on Saturday, please bring your sunscreen and water
bottle. We are expecting mainly fair weather conditions under
mostly sunny to partly cloudy skies, with temperatures in the mid
80s and heat indices in the low to mid 90s.

.LONG TERM...Monday through Friday...

.PREV DISCUSSION.../Issued 510 AM AST Apr 18 2024/

The next workweek will begin with a 60% chance of experiencing above
normal precipitation across the local islands. First of all, a high
pressure system northeast of the islands will maintain the winds
from the southeast at around 8 knots. A straight line of moisture
stretching from a low pressure system just east of the high pressure
will keep a dense Saharan-Air-Layer just south of the local islands
on Monday. However, small concentrations of these particulates could
reach the islands, so skies may look hazy at times. With moisture
lingering around, showers and isolated thunderstorms are anticipated
to develop along the Cordillera Central in the afternoon. The winds
from 850 to 700 mb are expected to be from the south, so this
convection will move northward, possible reaching portions of the
San Juan metro area.

Then, another low pressure system is expected to exit the eastern
coast of the United States, and the surface high will migrate
northward. The line of moisture will continue to meander around the
northeastern Caribbean, providing enough moisture to fuel afternoon
convection through Thursday. On Friday, additional induced patches
of moisture will be dragged across the region, but more breaks of
sunshine are expected.

Even with the afternoon rains, enough heating is expected late in the
morning, and with a southerly flow, temperatures will be on the hot
side, with highs reaching the upper 80s and low 90s, and heat
indices above the 100 degree mark.

&&

.AVIATION...
(18z)

Brief periods of MVFR conditions will remain possible at JPS and JSJ
in SHRA/TSRA through at least 19/23z. Aft 19/23z, mainly VFR conds
are expected to prevail with VCSH possible at JSJ/IST and ISX. Light
northeasterly winds to continue.

&&

.MARINE...

A light to gentle northeasterly wind flow will continue to prevail
across the local waters through at least early the next workweek,
becoming moderate from the east southeast on Monday. A small
northeasterly swell will move across the Atlantic waters through the
weekend.

&&

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

$$

SHORT TERM...LIS
LONG TERM....GRS
PUBLIC DESK...MRR