051 
FXZS60 NSTU 100040
AFDPPG

Area Forecast Discussion
National Weather Service Pago Pago  AS
140 PM SST Tue Oct 9 2018

.Short term TONIGHT THROUGH THURSDAY NIGHT...Latest visible
satellite imagery show showers with embedded thunderstorms across
the Samoan islands. This is associated with a surface trough that
remains near the islands this afternoon. As grounds have been
saturated from recent rainfall, any additional rainfall will
quickly lead to flooding and mudslides. Hence, we are maintaining
the flash flood watch for American Samoa through at least
Wednesday. Current model data show this trough moving slowly
westward through the week, with most of the rainfall expected to
move across American Samoa tonight through Wednesday, with a
downward trend Thursday as the trough migrates westward. However,
if this trough moves slower or faster than forecasted, the watch
for flash flooding will likely be cancelled earlier Wednesday or
extended to Thursday.

The gentle to moderate east winds will shift and become more
northeasterly late tonight through Thursday. We do expect for
higher gusts near showers and thunderstorms.

.Long term FRIDAY THROUGH TUESDAY...A high pressure system
centered far south of the islands will slowly migrate eastward. An
associated surface ridge will build south of the territory through
the long term, causing the winds to become more easterly through
the weekend. As the ridge is forecast to strengthen, the winds are
expected to become more southeasterly and reach fresh levels by
Sunday. Although this ridge is settled to the south of the
islands, expect showers embedded within the easterly flow to move
across the forecast area through the long term.

&&

.Marine...
Current PacIOOS Aunu'u wave buoy show heights remaining within the
5 to 7 feet range this afternoon. There are isolated long period
southerly swells, but not enough to meet advisory criteria for
high surfs. Latest SWAN Wave Watch III model output show heights
remaining within the current range and the winds are also expected
to stay below advisory criteria through the remainder of the week
with an increase in speeds by at least Sunday. Thus, we do not
anticipate any advisories for this week, but will likely issue a
small craft advisory due to the winds by Sunday.

&&

.PPG WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch remains in effect until Wednesday

&&

$$

Lutu-McMoore