Synoptic discussion for American Samoa.

338
FXZS60 NSTU 100107
AFDPPG

Area Forecast Discussion
National Weather Service Pago Pago AS
207 PM SST Mon Nov 9 2026

.Short term [tonight through Wednesday night]...
Short-term Moderate Drought (D1) has been introduced for American
Samoa by the US Drought Monitor following the second-driest
October on record. A persistent ridge of high pressure to the
south-southeast of the territory will not help the drought
situation in the short term, as it is projected to hold an active
trough north of the territory mostly stable weather conditions
with only scattered passing trade wind showers through at least
midweek. This is reflected in this afternoon`s 00Z RAOB upper-air
observation, which revealed a dry trade wind inversion at around
850 mb, consistent with current conditions.

The ridge of high pressure is also driving breezy southeasterly
trade winds across the islands. While gusty, these winds are
currently projected to remain just below Wind Advisory threshold
of 30 mph. However, similar impacts can be expected with winds up
to 25 mph with higher gusts expected.

.Long term [Thursday through Monday]...
By late week a second high pressure developing near New Zealand
and a low pressure to the northeast will lead to a subtle kink /
disturbance in the trade wind flow. This will act as a weak
surface convergence / trough and should bring at least a slight
increase in rainfall by Thursday or Friday to end the week.
However, due to the subtle nature of the surface trough,
confidence is low that enough rain will fall to provide any
relief for the newly-declared drought.

Aside from the weak troughing, the pattern will not change much
otherwise; as breezy trade winds are projected to remain. The
core of the active trough should remain north of the territory
through the long term forecast period. While no direct impacts
from the trough are expected this week; it is important to
remember that we are now in our Hurricane Season and tropical
systems can spin up from these types of active troughs, so we
will continue to monitor the situation going forward into next
week.

&&

.Marine...
Observed wave heights at the Aunu`u buoy have exceeded model
projections today, peaking at 11 feet this morning. With wave
heights having already exceeded 10 feet ahead of schedule, and
fresh to strong trade wind breeze expected to persist; not much
change is expected throughout the forecast period. Expect
hazardous, choppy wind driven waves near or exceeding 10 feet
throughout the forecast period, high surf for south through east
facing shorelines, and increased risk of powerful rip currents
throughout the forecast period. Mariners and those in surf prone
areas alike should heed caution as High Surf and Small Craft
Advisories should remain in effect throughout the week.

&&

.PPG WATCHES/WARNINGS/ADVISORIES...
High Surf Advisory
Small Craft Advisory

&&

$$

Barton