Area Forecast Discussion
Issued by NWS Pago Pago
Issued by NWS Pago Pago
477 FXZS60 NSTU 270101 AFDPPG Area Forecast Discussion National Weather Service Pago Pago AS 201 PM SST Thu Jun 26 2025 .DISCUSSION... Flash flooding conditions remains in the area as a trough is oriented northwest to southeast, connected to a low pressure system to the south of the islands. However, a drier portion of the trough has been more evident across the islands for the last 16 to 24 hours, giving a lower confidence in flash flooding criteria. These conditions are further supported by the upper air observations (RAOB) from this afternoon (27/00Z). Nonetheless, satellite imageries continue to show heavy thunderstorm activitiy embedded within the trough, keeping the probability of widespread showers across the watch area from time to time. Model data continues to show the trough lingering through at least the weekend. Therefore, the flood watch will remain in effect through at least tonight to account for thunderstorms in the area. Once the high pressure system to the south exits the region to the east by this weekend, the aforementioned low pressure system will also migrate away from the area. Will continue to monitor conditions as data becomes available. By Monday night, another high pressure system to the southwest will move south of the area as it generates moderate to fresh easterlies through the end of the forecast period. Embedded showers within the easterly flow is expected for this time frame. && .Marine... Seas and surfs continue to build and remain in the advisory thresholds for small crafts and high surfs. These conditions are supported by observations from the PacIOOS buoy near Aunu`u with wave heights around 9 to 12 feet and peak periods more than 10 seconds long. These observations converts to more than 13 feet of surfs. Also, thunderstorms activity embedded within the aforementioned trough will keep seas and surfs elevated nearby. Model data shows this trend remaining in the coastal waters through the weekend before subsiding to favorable conditions in the new week. With winds decreasing for this time frame, so as the seas. However, as a high pressure system to the southwest moves south of the region, winds will again increase by the end of this forecast period, and will likely generate choppy and rough seas for the new week. Thus, advisories for small crafts and high surfs will remain in effect through the weekend. && .PPG WATCHES/WARNINGS/ADVISORIES... High Surf Advisory Small Craft Advisory Flood Watch && $$ JTAllen