textproduct: WSO Pago Pago
This forecast discussion was created in the public domain by the National Weather Service. It can be found in its original form here.
DISCUSSION
Upper air data (RAOB) from this afternoon (11/00Z) show an inversion at around 850 mb to the mid-levels. A deep inversion layer as this indicates stable atmospheric conditions over the area. Also supporting these stable conditions are the open-cell cumuli clouds moving across the territory from the south, generated by a high pressure system. The open-cell cumuli clouds are normally associated with a high pressure system. These clouds have been recognized as shower clouds, which are able to produce showers for brief times, from time to time. Model data is showing the high pressure system migrating to the east and exiting the region by at least the weekend. By Sunday, easterly winds will decrease to a moderate flow through at least Monday.
Model data also show another high pressure system to the southwest, moving east, and generating southerly winds by the end of the forecast period. These southerly winds together with the gentle easterly winds will likely converge and create instability over the area for this time frame.
Thus, expect partly cloudy skies with scattered showers and breezy trades for the rest of the week. A more gentle to moderate easterly flow with an increased potential for showers is expected for the remainder of the forecast period.
Marine
Wind driven waves generated by the fresh to strong trades, produced by a strong high pressure system to the south will continue to impact south and east facing shores through at least the weekend. Data from the PacIOOS buoy near Aunu'u show heights peaking at more than 9 feet with peak periods reaching 12 seconds from time to time. This prompted the issuance of a high surf advisory earlier in the day through the weekend. The inconsistency in the long period data aligns with wind-driven waves and choppy conditions influenced by local winds versus swells generated by a storm at a distance. Model data shows this phenomena remaining for most of the week. By Saturday night into Sunday, winds will gradually decrease to a moderate easterly flow, improving ocean conditions for this time frame.
PPG WATCHES/WARNINGS/ADVISORIES
High Surf Advisory Small Craft Advisory
IMPORTANT This is an independent project and has no affiliation with the National Weather Service or any other agency. Do not rely on this website for emergency or critical information: please visit weather.gov for the most accurate and up-to-date information available.
textproduct.us is built and maintained by Joshua Thayer.