Area Forecast Discussion
Issued by NWS Pago Pago
Issued by NWS Pago Pago
884 FXZS60 NSTU 220029 AFDPPG Area Forecast Discussion National Weather Service Pago Pago AS 129 PM SST Thu Aug 21 2025 .Discussion... Latest satellite data shows the trough mentioned in previous forecast slowly approaching the territory from the northeast. It appears the trough has become more active as clouds are more convective than this morning. GDI patterns (instability model data) depicts an uptick in moisture and instability later tonight when the trough moves over the Samoa Island chain. This scenario suggests thunderstorm activity and heavy rainfall are possible. Hence, a flash flood watch is in effect to monitor the development of the trough through Friday. Additionally, seasonal trade winds will hold in the area for the weekend. The trough is forecast to continue its southwest track on Friday. Showers are expected to diminish by Friday afternoon as the trough moves further away, so the watch will likely drop before or during this time. Expect scattered showers and breezy east winds for the remainder of the forecast period. && .Marine... Wave heights continue to build as breezy winds linger in the area. This is evident on the Aunu`u PacIOOS buoy indicating heights reaching near 8 feet. Strong south swells that prompted the high surf advisory yesterday is starting to show a downward trend as it slowly exits the region. However, a high surf advisory will continue through the new week as waves are forecast to peak Sunday. A southeast swell will hold seas and surfs in the advisory thresholds for this timeframe. .PPG WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch High Surf Advisory Small Craft Advisory && $$ TM