Area Forecast Discussion
Issued by NWS Pago Pago
Issued by NWS Pago Pago
257 FXZS60 NSTU 210135 AFDPPG Area Forecast Discussion National Weather Service Pago Pago AS 235 PM SST Mon May 20 2024 .Short term... A strong ridge of high pressure remained dominant throughout the day over the American Samoa islands. Low relative humidity along the lower levels of the atmosphere has made it difficult for cumulus clouds to develop, let alone clouds that would produce showers. The steady easterly trades and only a slight risk of a weak passing shower will continue through at least Tuesday. There is high confidence that there will not be any flash flooding during this time. More sun than clouds are expected during the day with temperatures above average. By mid-week, the aforementioned ridge from the southeast will continue to move away from the region. This will allow a trough, currently to the north of American Samoa, to move south towards the territory. The majority of the moisture within the trough will likely move to the west of American Samoa, but the risk of showers increase from Wednesday night through the rest of the week. The highest risk for passing showers will be on the evening of Thursday and into Friday morning. Easterly trades will decrease slightly, but still remain up to around 15 mph during this time. The strength of the rainfall is not expected to reach high enough to cause flash flooding in the region. .Long term... Overall, no severe weather is anticipated for the weekend and into early next week. Another trough is expected to develop near the Fiji region, but the heavy rainfall would remain away from the territory. Easterly winds will generally weaken, but remaining around 10 mph. && .Marine... The latest altimeter data from the recent POES satellite shows that seas remain between 7 to 9 feet along the American Samoa coastal waters. The fresh easterly trades will slowly weaken to a moderate easterly breeze throughout the week. Since there are no significant swell expected to move through the region and winds slowly decrease, sea heights will also slowly ease throughout the week. Surf along the eastern shorelines are in the lower thresholds for a High Surf Advisory, which is expected to expire by Tuesday evening. The Small Craft Advisory may be set to expire by late in the week. && .PPG WATCHES/WARNINGS/ADVISORIES... A High Surf Advisory remains in effect. A Small Craft Advisory remains in effect. && $$ LaPlante