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FXZS60 NSTU 150126
AFDPPG

Area Forecast Discussion
National Weather Service Pago Pago  AS
226 PM SST Sun Dec 14 2025

.Discussion...
Latest satellite data shows an active trough southwest of the
territory, which has characteristics that suggest it is the South
Pacific Convergence Zone (SPCZ). The SPCZ will influence weather
conditions for the week, bringing possible widespread showers and
strong winds.

Thunderstorms are evident to the west of Savai`i on satellite,
indicating the SPCZ is extending closer to the Samoa Island chain.
The upper air sounding from this afternoon also depicts a moist
environment. As the trough edges over the Islands Monday morning,
the risk for flash flooding will increase. Hence, a Flash Flood
Watch is in effect through Thursday as we monitor the development
of the SPCZ. Light winds will hold through Tuesday.

By Wednesday, a low pressure system to the south (Currently known
as Tropical Cyclone (08P)/Tropical Depression (03F)) is expected
to bring the trough back over the Islands as it tracks east-
southeast. We remember from previous events that winds from the
northwest tends to be stronger downslope mountain ranges,
especially in the harbor area as it funnels through the harbor.
Expect winds to reach advisory levels if this plays out through
Thursday.

Please note that our confidence is low at this time, especially
as models vary on whether TC 08P/TD 03F diminishes as it passes
Fiji, or continues east (passing south of us). However, model data
has been consistent on holding the SPCZ over or near the Samoa
Islands through the end of the week, so still expect showers and
strong winds.

&&

.Marine...
Wave heights at the PacIOOS buoys are around 4 to 6 feet, which
suggests calm ocean conditions due to light winds. Although there
is a signal of a north swell (peak periods of 13 to 14 seconds for
the north direction), seas remain fairly calm. However, as winds
increase by midweek, expect ocean conditions to also build. Model
data suggests a sharp increase as the low pressure passes south
by midweek. This means wave heights can go from 5 to 7 feet to 8
to 10 feet or higher within a short time span. We will continue to
monitor how this plays. However, expect seas to return to a calmer
state by the weekend.

&&

.PPG WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch

&&

$$

TM