Area Forecast Discussion
Issued by NWS Pago Pago
Issued by NWS Pago Pago
616 FXZS60 NSTU 030019 AFDPPG Area Forecast Discussion National Weather Service Pago Pago AS 119 PM SST Thu May 2 2024 .Short term... Overall, rainfall will be above average through the weekend. A Flood Watch is in effect for all islands of American Samoa through Friday. A strong trough remains in the vicinity of American Samoa. Satellite imagery this morning and early this afternoon shows an impressive amount of rain and thunderstorms just to the east/northeast of the territory. This convection is expected to move closer to the region later this afternoon and through the overnight hours. Heavy rainfall and gusty winds may occur in areas of thunderstorms. Due to the possibility of heavy rainfall and the large area of rain moving towards the territory, a flood watch is in effect for all islands of American Samoa through Friday. Winds during this time will shift from east to northeast and will decrease in strength in areas away from localized thunderstorms. For Friday, there are signs that thunderstorms may move away from the islands. The rainfall forecast of widespread showers decrease to numerous showers (70% chance), but rain is still likely. Winds decrease to around 10 mph. This weekend, however, a ridge to the southeast will help steer another trough to bring more moisture over the territory. Precipitable water exceeds 2.5 inches with high instability values as the trough moves in. This could lead to the potential for more flooding for all islands, pending on the exact location of the trough. We will continue to monitor this timeframe as the current Flood Watch may be extended through the weekend if the outlook continues to show this advise weather pattern. Winds will decrease to a light northerly breeze, but gusts may occur in areas of thunderstorms. .Long term... Finally by the beginning of next week, the aforemetioned troughs will move to the south. Scattered to numerous showers are forecast as the air is still moist and could trigger some passing showers through the middle of the week. A light northerly wind is expected to become a light easterly wind by the middle of the week. && .Marine... Active showers and thunderstorms are expected to remain along the coastal waters region overnight. An easterly fresh breeze will become more of a moderate northeasterly breeze throughout the evening and overnight, but strong wind gusts may occur near localized thunderstorms. Seas are expected to remain elevated, between 8 to 10 feet through Friday morning. Winds will decrease to a gentle to moderate northerly breeze by Friday afternoon and the weekend, but seas are only expected to ease to around 6 to 8 feet through Saturday night. By Sunday, the trough will begin to move southeast of the territorial waters. However, a strong swell from the south is expected to move over the region for early next week to keep sea heights at Small Craft Advisory levels and the potential for a surf to reach High Surf Advisory status. && .PPG WATCHES/WARNINGS/ADVISORIES... A Flood Watch is in effect. A Small Craft Advisory remains in effect. && $$ LaPlante