239 FXZS60 NSTU 060100 AFDPPG Area Forecast Discussion National Weather Service Pago Pago AS 200 PM SST Fri Jun 5 2026 .Short term [tonight through Sunday night]... 00Z RAOB upper-air observation this afternoon continues to reveal a very dry and stable atmospheric profile with a mid-level temperature inversion. Any convection that does occur in this environment would be brief and shallow, unable to build above the stable inversion layer. A developing equatorial surface trough is observed on satellite to the north of the territory. Surface high pressure to the south will continue to hold this trough north of the islands through the period, bringing stable weather conditions and breezy trade winds for American Samoa. The ridge of high pressure to the south will slowly migrate eastward, gradually decreasing trade winds to around 10 mph by Sunday. All available data points towards a similar evolution making confidence in the forecast for the short term forecast period very high: below average rainfall with any isolated showers being brief in nature as trade winds gradually weaken into Sunday .Long term [Monday through Friday]... A new ridge of high pressure currently developing over Australia will push eastward into the Southwest Pacific Basin and drive the weather pattern for the long term forecast period. This ridge is forecast to begin building southeasterly surface trade winds over American Samoa by Monday, nearing 30 mph by late Tuesday and remaining strong for the rest of the week. This ridge should hold the aforementioned equatorial trough north of American Samoa through the first half of the week. However, the ridge is forecast to push another trough that is currently near New Zealand and Vanuatu eastward and into the area by early next week. Models depict that this trough will weaken significantly before reaching the Samoan islands, but should still increase atmospheric moisture enough to increase rain chances to scattered early next week. By midweek, the equatorial trough to the north is forecast to strengthen as equatorial low pressure pushes the trough southward and near the American Samoa islands by the latter half of the week. Numerous to widespread showers are likely for the Thursday through Friday timeframe. It is too early to determine if this trough will bring a threat for flash flooding due to heavy uncertainties in it's exact progression at this extended range. && .Marine... Today's marine observations from Aunu'u buoy indicate wave heights of around 7 to 8 feet driven by the moderate to fresh southeasterly breeze. This may make marine navigation difficult, especially for inexperienced mariners operating smaller vessels. Seas should slowly subside to below advisory levels by Saturday night into Sunday as trade winds gradually weaken. Favorable sea conditions are expected late this weekend through early Tuesday. As strong southeasterlies build by late Tuesday, seas will begin building again. Seas and surfs are forecast to build to hazardous levels by Wednesday with High Surf Warning issuance being possible by mid to late week. && .PPG WATCHES/WARNINGS/ADVISORIES... Small Craft Advisory remains in effect && $$ Barton