Area Forecast Discussion
Issued by NWS Pago Pago
Issued by NWS Pago Pago
416 FXZS60 NSTU 190115 AFDPPG Area Forecast Discussion National Weather Service Pago Pago AS 215 PM SST Wed Sep 18 2024 .Short term... Latest satellite data shows showers just south of the Islands tied to a stationary front, while those to the northwest are connected to a trough. Meanwhile, the Samoa Island chain is experiencing dry and stable conditions between the two features. Model data continues to build a high pressure behind the frontal boundary on Thursday. This high pressure system appeared to be stronger in the past few days, but have slightly weakened in the latest model updates. Hence, instead of southeast winds of 15 to 25 mph expected Thursday, winds are now forecast to be in the range of 10 to 20 mph. Nonetheless, model data are consistent in the front diminishing in the area by Thursday as the aforementioned high pressure moves closer to the Islands. .Long term... Expect an uptick in showers on Friday as moisture is seen moving in from the north along with showers embedded within the southeast flow. Scattered showers and southeast winds of 10 to 20 mph will remain through Monday. As the high pressure exits the region Monday night, another high pressure will build near New Zealand. This feature will continue a similar weather pattern through midweek. && .Marine... Peak periods continue near 15 seconds due to a large southwest swell, while wave heights remain around 4 to 6 feet. Current peak periods suggests the strong swells will hold dangerous rip currents and high surfs along the southwest coastline through Thursday. Hence, a high surf advisory remains in effect until then. However, with the impending winds on Thursday, seas are forecast to remain at advisory thresholds through Sunday. Thereafter, another set of strong southwest swells is expected in the area Monday. && .PPG WATCHES/WARNINGS/ADVISORIES... High Surf Advisory && $$ TM