American Samoa's Tropical Cyclone Outlook 2025-26

Below Normal to Near Normal Tropical Cyclone (TC) Activity anticipated for American Samoa in the 2025-26 TC Season Read More >

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FXZS60 NSTU 200030
AFDPPG

Area Forecast Discussion
National Weather Service Pago Pago AS
130 PM SST Sun Apr 19 2026

.DISCUSSION...
The latest satellite imageries show a shortwave trough to the
north-northeast moving towards the Samoa Islands. Possible
thunderstorm activity with convective clouds embedded within this
shortwave trough may briefly increase the potential for unstable
conditions over the islands, overnight tonight. Model data shows
the trough moving over the area through at least early Monday.
Minor flooding may be observed throughout the islands during this
time frame.

By Monday night, model solutions show improving conditions with
signals of trade wind season developing early in the area. A high
pressure system anchoring to the southeast of the area as it
generates moderate easterlies with embedded showers will remain
through midweek. Another broad high pressure system to the
southwest will migrate east as it continues to hold easterlies
with embedded passing showers over the area. Additionally, model
data shows a mid-level high pressure system lingering over the
area, likely suppressing any deep convections throughout the week.

Therefore, expect scattered showers for tonight becoming numerous
overnight tonight with possible thunderstorms and gentle east
winds. Moderate to fresh easterlies with embedded showers will
persist for the rest of the week.

&&

.Marine...
Observations from the PacIOOS buoys (Aunu`u & King-Poloa)
continue to show ideal ocean conditions across American Samoa
waters. Combined seas of 4 to 6 feet remains, occasionally
subsiding to below 4 feet as periods peak around 11 seconds.
Model solutions show these conditions slightly elevating to 5
to 7 feet tonight through at least Tuesday. By Tuesday night, a
southwest swell will reach American Samoa coastal waters as it
potentially builds to advisory thresholds on Wednesday. Model
data also show peak periods reaching more than 13 seconds long,
enhancing surfs and potentially generating strong rip currents.
Gentle to moderate easterlies for this time frame may generate
a mixture of wind waves with the aforementioned swell from time
to time. Seas will gradually subside thereafter.

&&

.PPG WATCHES/WARNINGS/ADVISORIES...
NONE

&&

$$

JTAllen