textproduct: WSO Pago Pago

Long term [Monday through Friday]

The high pressure system near New Zealand will begin to gradually weaken and move to the east to start the new week. This will allow the developing low pressure near Vanuatu to drift southeast, moving near Fiji and continuing to the south of American Samoa by early through midweek. As this area of low pressure moves south of the territory, it will pull the trough to the north closer to the islands. This is forecast to bring increased rain chances by as early as Monday night continuing through midweek. However, there is still signficant model disagreement regarding the exact progression of this trough, so potential for flooding is uncertain at this time.

With the pressure gradient weakening over the early to mid-week time frame, trade winds should weaken below advisory levels Monday into Tuesday as they begin to turn out of the north to northeast, becoming a light flow by Wednesday. Light winds and passing showers are forecast for late week as the trough moves away to the southeast.

Marine

Today's data from Aunu'u buoy show that combined seas with a large south swell and southeasterly wind waves are continuing to bring very large and hazardous seas and surf to American Samoa's coastal waters and south facing shorelines. The swell component is gradually weakening with time. The swell is expected to weaken enough by tomorrow to make the short period southeasterly wind driven waves the dominant wave component.

As the swell weakens, wave heights may briefly subside 9 to 12 feet tomorrow. However, strong to near gale force winds over the weekend should build seas back to 10 to 14 feet by Sunday. With lower period times, surf heights will decrease slightly, but will remain at high-end advisory to borderline warning levels, capable of sweeping away people near vulnerable shorelines and generating powerful rip currents. These large and choppy wind driven waves will make navigation extremely difficult to impossible for small vessels and inexperienced mariners. Seas are expected to begin gradually subsiding Tuesday as wind speeds decrease, but will still remain rough until midweek.

PPG WATCHES/WARNINGS/ADVISORIES

High Surf Warning remains in effect. Wind Advisory remains in effect. Small Craft Advisory remains in effect.