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2021- 2022 Tropical Cyclone (TC) Outlook for American Samoa

Tropical Cyclone Outlook for American Samoa for this upcoming TC Season (November 1, 2021 to April 30, 2022) Read More >

FXZS60 NSTU 290106

Area Forecast Discussion
National Weather Service Pago Pago AS
206 PM SST Fri Jan 28 2022

The prolonged domination of the South Pacific Convergence Zone
(SPCZ) over the territory has finally come to an end. A strong
ridge over the Samoa Island chain has taken over weather patterns
and will linger in the area through the new week. This trend is
evident on latest satellite loops showing fair weather conditions
associated with the ridge, with open-cell cumuli indicating
showers embedded with the trade wind flow. To the west of Savai`i
is a line of convective clouds outlining the SPCZ.

Model data depicts that the ridge will produce breezy conditions
(15 to 20 mph) and scattered showers through at least Saturday. By
Sunday, a weak boundary will develop over the Islands due to a
mid-level low south east of Manu`a. This pattern will enhance
showers by Sunday night, which will continue through midweek. For
the second half, expect showers to diminish and breezy winds to
increase once again due to another ridge that is anticipated to
build by this time.


Latest observations from the Aunu`u PacIOOS buoy keep wave heights at
advisory thresholds through Saturday due to breezy winds and
northerly swells combined. As model data diminishes winds by
Saturday, expect seas to also follow this subsiding trend. A high
surf advisory will remain in effect tonight, while the small craft
advisory will continue through at least Saturday when winds
finally drop below 20 knots. Thereafter, no signficant swells are
anticipated until Sunday as large north and south swells move in
the area. However, even with these swells, significant wave
heights will remain at the 5 to 7 foot range for the rest of the
forecast period.

High Surf Advisory
Small Craft Advisory