Area Forecast Discussion
Issued by NWS Pago Pago
Issued by NWS Pago Pago
469 FXZS60 NSTU 030106 AFDPPG Area Forecast Discussion National Weather Service Pago Pago AS 206 PM SST Thu Oct 2 2025 .DISCUSSION... Deep and active convections embedded within a trough over the islands is shown concentrated just north of the territory. On satellite imageries together with model data, it shows these deeper convections migrating closer to the islands tonight through the weekend. However, the upper air observations (RAOB) from this afternoon (03/00Z) shows dry conditions over the area. What stands out are the moderate to fresh east-southeast surface winds, holding the convections to the north. By the overnight hours tonight, models are showing an increase in precipitation as winds decrease to a more gentle to moderate east wind flow. This will potentially allow the trough to migrate south and over the islands. Nearby thunderstorms will also increase winds to gusty conditions. A high pressure system to the south generating the moderate to fresh easterlies and holding the trough to the north will continue to migrate east through at least Sunday. Model data shows another high pressure system to the southwest, migrating east as it pushes another boundary layer over the islands by Sunday night. This will also likely increase the potential for showers and decrease wind strength. Therefore, expect scattered showers with moderate to fresh easterlies for tonight through the weekend, increasing to numerous showers in the overnight hours, tonight. Embedded showers within the easterly flow will remain for the rest of the forecast period with gentle easterlies turning southeast on Tuesday night. && .Marine... Manual observations of ocean conditions throughout the day show white caps in the open waters. This is an indication of strong winds in those areas. The latest data from the PacIOOS buoy near Aunu`u show heights around 6 to 8 feet with periods less than 10 seconds. These are consistent with the east-southeast fresh breeze. Another set of swell from the south-southwest are impacting south to west shorelines. Data from the PacIOOS buoy on the west side of Tutuila Island show seas at a lower height (4 to 6 feet) with periods peaking at 15 to 16 seconds long. With the long periods, the risk of rip currents is likely. Model data show seas remaining steady at 6 to 8 feet throughout the forecast period. There are no other significant swells expected for this forecast period. However, with the aforementioned trough remaining over the islands as it intensifies in the next couple of hours, and the king tides expected towards the end of the forecast period, seas and winds will keep ocean conditions moderately impactful. Therefore, the small craft advisory will remain in effect. && .PPG WATCHES/WARNINGS/ADVISORIES... Small Craft Advisory && $$ JTAllen