Synoptic discussion for American Samoa.

585
FXZS60 NSTU 180032
AFDPPG

Area Forecast Discussion
National Weather Service Pago Pago AS
132 PM SST Fri Jan 17 2025

.Short term...
TONIGHT THROUGH SUNDAY NIGHT
Latest satellite data shows that the South Pacific Convergence
Zone (SPCZ) has weakened, but moisture and instability remain with
remnant troughing. An increase in rainfall coverage has begun
today and is expected to continue through at least Sunday night
associated with this troughing activity that has now moved over
American Samoa. Satellite and model data supports that the dry
mid-levels are slowly moistening due to the trough. However, this
airmass should remain dry enough to prevent a flash flooding
threat due to high pressure in the mid-levels, but minor localized
flooding will be possible.

.Long term...
MONDAY THROUGH FRIDAY
On Monday, the flow will begin to enter into a trade wind regime.
A steady easterly trade wind flow is forecast by Monday night.
This easterly trade wind flow with winds of 10 to 20 mph and
scattered to numerous passing showers are forecast to continue
throughout the remainder of the forecast period.

&&

.Marine...
Seas of 5 to 7 feet have been observed at Aunu`u and King Poloa
buoys today. These low seas are forecast to continue through the
remainder of the forecast period. Late Saturday into early Sunday,
the peak period is forecast to increase to up to 20 seconds
associated with a north swell. We will closely monitor the trend
in peak period for the potential for High Surf Advisory criteria
to be met for northern shores this weekend into early next week.
Otherwise, ideal conditions are forecast for mariners until winds
increase on Monday night.

.PPG WATCHES/WARNINGS/ADVISORIES...
None

&&

$$

Barton/Meredith Leiato

American Samoa's Tropical Cyclone Outlook 2024-2025

Synoptic discussion for American Samoa.