280
FXCA62 TJSJ 242012
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
412 PM AST Sun Nov 24 2024

.SYNOPSIS...
Plenty of clouds will continue to cover the skies. Drier
conditions are expected Monday and Tuesday, before another area of
showers arrives on Tuesday and Wednesday. Drier weather is
anticipated again for Thanksgiving Day. Marine and beach
conditions will deteriorate this week as a north-northwesterly
swell arrives.

&&

.SHORT TERM...Tonight through Tuesday...

Showers and thunderstorms developed across the local waters of the
US Virgin Islands, moving inland and creating minor flooding,
especially across St Croix. This activity later moved across the
eastern third of PR, creating showery weather with moderate to heavy
rain periods. By mid-morning, rain activity dissipated, but skies
remained mostly cloudy. Additional showers developed in the
afternoon, especially along Rincon and San Sebastian, and isolated
activity also appeared again over portions of eastern Puerto Rico.
Maximum temperatures across the coastal areas were in the mid or
upper 80s along the coastal areas and the upper 70s or low 80s in
mountains and valleys.

A frontal boundary extending from the windward passage into the
Atlantic Ocean north of PR and the USVI will induce a pre-frontal
trough near the islands, interacting with a weak tropical wave and
promoting unstable weather conditions. Local effects with sea
breeze variations will promote isolated to scattered showers
across the northern half portion of PR. These showers may result
in urban flooding with the most vigorous activity. A mid to upper-
level high pressure will increase the instability across the
northeast Caribbean with a somewhat drier air mass moving from the
east at the surface, promoting tranquil weather conditions across
most islands. However, the potential for the development of
showers and isolated thunderstorms will be present, especially
across the coastal and offshore waters in the Atlantic and along
the Atlantic coastline of PR.

The frontal boundary will linger north of the islands while a
surface high pressure builds from the western Atlantic to the
central Atlantic, promoting. Therefore, a more tranquil weather
pattern is expected for Monday and Tuesday, under the typical
morning and overnight passing showers across the windward
sections, followed by afternoon convection across the western
portions.

.LONG TERM...Wednesday through Sunday.../from prev discussion/

A building surface high pressure over the central Atlantic and a
broad surface low south of Hispaniola and Jamaica will be the
dominant weather features for the long-term period. The
aforementioned features will promote a southeasterly wind flow
through the end of the weekend. The latest precipitable water
content analysis (PWAT) has values of 1.80 to 2.00 inches from
Wednesday into late Saturday suggesting abundant moisture content to
remain over the islands. With the presence of the surface low west
of the region, the better moisture content will remain over portions
of the Dominican Republic. However, the wind will continue to bring
pulses of moisture over the islands and promoting the development
of showers and thunderstorms over the region each day. By the end
of the period, winds will shift from the east. Much drier air
will start to filter into the area, improving weather conditions
across the area until the middle of next week. Daytime
temperatures will stay in the upper 80s to low 90s across the
coastal and urban areas of the islands, and in the low to mid 80s
in the higher elevations.


&&

.AVIATION...

VFR conditions will persist across most of the local flying area,
with some SHRA/-SHRA arriving occasionally. Winds will continue
from the E/ESE at 10 to 15 kt, becoming calm to light and VRB
after 24/23z, but returning from the E at around 15 kt with higher
gusts after 25/13z.

&&

.MARINE...
A frontal boundary extending from the windward passage into the
Atlantic Ocean north of PR and the USVI will induce a pre-frontal
trough near the islands, interacting with a weak tropical wave,
promoting unstable weather conditions. A north northwesterly swell
will arrive later tonight, deteriorating the local marine and coastal
conditions through at least mid- week. The frontal boundary will
linger north of the islands while a surface high pressure builds from
the western Atlantic to the central Atlantic.

&&

.BEACH FORECAST...
The risk of rip currents will remain high across the north-facing
beaches of Puerto Rico, including Vieques and Culebra, and across
the Virgin Islands through at least mid-week. There is another
long-period northerly swell arriving later in the week, so it is
likely that the risk will have to be extended through the end of
the week.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk through Tuesday afternoon for PRZ001-002-
     005-008-010-012.

VI...High Rip Current Risk through Tuesday afternoon for VIZ001-002.

AM...Small Craft Advisory from midnight tonight to 6 PM AST Tuesday
     for AMZ711-712-716.

&&

$$

SHORT TERM AND AVIATION DISCUSSION...CAM
RADAR/BEACH DISCUSSION....ERG
MARINE/UPPER AIR...MMC