textproduct: WSO Pago Pago

Long term

By Tuesday, the surface convergence and primary trough should move further southward from the territory. However, it is expected to remain close enough to provide sufficient remnant moisture to support numerous passing showers and possibly an isolated thunderstorm. Winds will likely become light and variable over this midweek time frame. By late week into the weekend, the trough is expected to move back north and over the territory, increasing the potential for flash flooding and thunderstorms. Convergent easterly winds are likely to build over the territory for this time frame.

The past three runs of the operational GFS model depict a tropical low developing near American Samoa as the trough moves back over the territory by late week. The chance of this scenario occurring remains very low at this time (10% potential tropical formation chance according to the Joint Typhoon Warning Center) as the GFS is only one model out of the large suite of available model data, and forecast accuracy is much lower beyond three days. However, the run-to-run consistency of this GFS trend is still concerning enough that it will need to be closely monitored going forward.

Marine

Seas have been increasing throughout the day, with combined seas now observed in the 6 to 8 foot range at Aunu'u buoy. Given peak period times around 15 seconds associated with a north swell, critieria is met for High Surf Advisory. Therefore, Advisories for High Surfs and Small Crafts are now both in effect. Seas will remain rough throughout the week, likely peaking Monday in the 7 to 9 feet range as a fresh breeze to the southeast of the territory generates a strong short period swell across the territorial waters. Seas could increase 7 to 9 feet again late week as easterly winds build across the territorial waters.

PPG WATCHES/WARNINGS/ADVISORIES

High Surf Advisory Small Craft Advisory