Area Forecast Discussion
Issued by NWS Pago Pago
Issued by NWS Pago Pago
901 FXZS60 NSTU 210119 AFDPPG Area Forecast Discussion National Weather Service Pago Pago AS 219 PM SST Sun Sep 20 2026 .Discussion... Latest satellite data shows convective clouds associated with a trough focused southwest and east of the Samoa Island chain. As thunderstorms to the east edge closer to the Manu`a Islands, an uptick in showers is expected across the territory tonight. Shower activity will likely increase further on Monday as convection to the east interacts with additional convection to the south. Meanwhile, a high pressure system building behind the trough will continue to usher in east to southeast winds of 10 to 20 mph. These winds will persist through midweek before shifting to the east. The chance for showers will also diminish around this time as the trough moves westward. However, the trough is expected to migrate back toward the territory by the end of the week before the aforementioned high pressure system builds in on Saturday. Breezy conditions are expected to return as the high pressure system tracks eastward. && .Marine... Calm seas observed earlier this morning continue to trend toward a more texture surface as winds increase to near 10 knots. Ocean conditions are expected to reach Small Craft Advisory thresholds by Monday as winds build to around 20 knots. Additionally, a south to southwest swell currently evident at the PacIOOS buoy shows peak periods around 14 seconds, indicating a strong swell signal. Although the swell remains well defined, current wave heights of 5 to 7 feet remain below High Surf Advisory thresholds. Choppy ocean conditions are expected to persist through the week as winds remain near or at 20 knots. && .PPG WATCHES/WARNINGS/ADVISORIES... None && $$ TM