645
FXZS60 NSTU 260117
AFDPPG

Area Forecast Discussion
National Weather Service Pago Pago AS
217 PM SST Wed Mar 25 2026

.Short term...

Satellite imagery this morning shows a trough in the vicinity of
the American Samoa islands with most of the rainfall just to the
north of the territory. The likelihood of showers remain numerous
(60 to 70% chance) for tonight and tomorrow as the trough is
forecast continues to linger over the area. Winds are forecast to
be generally light, but gusts may occur in showers.

By Thursday night, a ridge from the east comes closer to the area
as well as another ridge strengthening from the south. This is to
produce strong wind convergence along the trough. The trough is
also anticipated to intensify as a low pressure system to develop
to the southeast. This is a typical South Pacific Convergence Zone
(SPCZ) setup. The SPCZ is forecast to move over, or at least
near, the American Samoa islands on Friday through the weekend.
Consistent and/or heavy rainfall at times is forecast throughout
this time, which may lead to flash flooding. With this amount of
rainfall, there is an increased risk of landslides. Also,
northwesterly winds are to form along the trough and may reach up
to 20 mph with stronger gusts near heavy rainfall. The Pago Pago
Harbor region typically receives stronger winds from this
direction. We will continue to monitor the projected position and
the strength of the SPCZ for the potential of a Flood Watch during
this time.

.Long term...

By early next week, the SPCZ is forecast to weaken as it slowly
moves south of the area. The likelihood of rain remains numerous
(60% chance), pending on the exact location of the trough. Even if
the trough remains over the region, the strength of the trough is
to weaken. Northwesterly winds on Monday also weaken and becomes a
light easterly breeze by midweek.

&&

.Marine...

The PacIOOS buoys to the west of Tutuila and to the east of Aunu`u
shows southeasterly and northerly swells moving through the
American Samoa coastal waters. These swells had seas build up to
around 8 feet throughout the day. However, period timing and
strength of the swells are forecast to continue decreasing through
the evening hours. The High Surf Advisory is likely to be lifted
by late tonight/early Thursday morning.

We are monitoring the potential for the South Pacific Convergence
Zone (SPCZ) to develop along the coastal waters on Friday through
the weekend. This is forecast to create a moderate to fresh
northwesterly breeze during this time, but may be stronger along
the Pago Pago Harbor region. Seas are expected to be choppy with
waves reaching up to 9 feet. Seas will slowly ease throughout the
upcoming week.

&&

.PPG WATCHES/WARNINGS/ADVISORIES...

A High Surf Advisory remains in effect.
A Small Craft Advisory remains in effect.

&&

$$

LaPlante