272
FXZS60 NSTU 100106 CCA
AFDPPG

Area Forecast Discussion...CORRECTED
National Weather Service Pago Pago  AS
206 PM SST Sun Aug 9 2026

.Short term [tonight through Tuesday night]...
The ridge to the south continues to move eastward, this has
shifted the strongest trade winds east of American Samoa in the
latest satellite wind estimate (ASCAT) data. However, wind speeds
still remain at borderline Advisory levels for American Samoa.
Therefore, the Wind Advisory will continue through tonight.

The eastward shift in the ridge has also brought continued
atmospheric moistening and gradual erosion of the stable trade
wind inversion (as seen in this afternoon`s 00Z RAOB upper-air
observation). This has maintained cloudy skies and an increase in
trade wind showers across the American Samoa islands today. These
showers are typically brief, and are not expected to bring a
flooding threat.

Going forward through the remainder of the short term forecast
period, expect a continued slow decrease in wind speeds as the
ridge shifts eastward. Despite likely decreasing below Advisory
levels by tomorrow, these winds should still remain breezy.
Scattered to numerous passing trade wind showers are likely to be
embedded within this flow.

.Long term [Wednesday through Sunday]...
By midweek, as the first ridge shifts out of the region to the
east, another ridge will form to the south. Another strong high
pressure center should form southeast of New Zealand. However, a
weaker and more disorganized ridge between the Samoan Islands and
New Zealand is anticipated be the system that drives the weather
pattern for the long term forecast period.

Given the weaker nature of this ridge, the trade winds are not
forecast to reach the same strength as with the current pattern,
but may still be breezy at times (up to 20 mph). However, while
weaker, the ridge`s much closer proximity is forecast to lead to
a more considerable trade wind inversion. GFS model proximity
soundings for American Samoa depict an extremely dry and stable
layer above the low-level moisture for much of the long-term time
frame, limiting convective cloud growth. Any isolated to
scattered showers beneath this inversion should be light and
brief in nature.

&&

.Marine...
Large trade wind driven waves combining with a south swell
continue to produce very large seas (12 to 15 feet), Warning
level surf, and increased risk of dangerous rip currents through
at least tonight. Going into the new week, wave and surf heights
will begin to slowly subside due to the weakening trade winds.
However, Advisory level sea and surf conditions should maintain
for at least most of the week. Mariners and beachgoers alike
should continue to monitor latest forecasts and proceed with
caution.

&&

.PPG WATCHES/WARNINGS/ADVISORIES...
High Surf Warning remains in effect.
Wind Advisory remains in effect.
Small Craft Advisory remains in effect.

&&

$$

Barton