Area Forecast Discussion
Issued by NWS Tiyan, Guam
Issued by NWS Tiyan, Guam
501 FXPQ50 PGUM 060734 AFDGUM Area Forecast Discussion National Weather Service Tiyan GU 534 PM ChST Sun Sep 6 2026 .Marianas Synopsis... Satellite and radar imagery depicts mostly cloudy skies, scattered showers, and isolated thunderstorms quickly moving across the region. Combined seas are around 3 to 5 ft. && .Discussion... A nearly-stationary col as well as upper-level divergence has maintained the convectively active, wet pattern today. After midnight, a lull in showers and light northerlies may allow for enough clearing for scattered, island-effect rainfall Monday afternoon. Due to the slow-moving nature of the convergence zone, isolated thunderstorms are possible through Monday. Then, drier conditions are possible for a few subsequent forecast periods as the active weather pattern exits the region to the northwest. As for the latter half of the week, northerlies may increase in speed to light to gentle. Shower coverage may differ as model guidance hints at a potential circulation developing to the east of the islands. Due to the high uncertainty regarding this pattern, showers top out at 30 percent through Saturday with a slight chance of thunderstorms returning. This will continue to be refined as confidence naturally increases with time. Shortly thereafter, a dry spell is possible entering early next week. && .Marine... The westerly swell continues to subside, allowing for combined seas to drop to 3 to 5 ft tonight, followed by another decrease to 3 to 4 ft Monday. Light to gentle northwesterlies will shift to the north Monday and eventually to the northeast later in the week. There is a moderate risk of rip currents along north, south, and west facing reefs, with the former two dropping to a low risk beginning Monday. Island-effect showers may be a concern Monday afternoon for southern coastal waters. && .Eastern Micronesia... Very little change to the previous forecast. Maintained isolated showers at Pohnpei and Kosrae through Monday night. A re-invigorated monsoon trough is expected to bring increased showers to Majuro later this evening, ending the dry pattern there. This will initiate an overall unsettled pattern spreading across eastern Micronesia that will continue across the Marshalls through the end of the week. The convection will spread west over the next day, bringing this pattern to Kosrae and Pohnpei Tuesday. This pattern will then continue through the end of the week. No major changes were made to the marine forecast. Seas could climb to as high as 7 feet after midweek. Light to gentle winds will become gentle to moderate at Kosrae Monday, then become moderate to fresh around midweek and remain there through at least Friday. Pohnpei will see gentle to moderate winds Tuesday that will continue through the end of the week. For Majuro, winds will become light to moderate Monday, returning to light to gentle by midweek. && .Western Micronesia... A ridge extending from a buffer circulation near West Papua is still inducing some diffluent flow over Yap and Palau, leading to quiet conditions over the next few days. During this period of drier weather, haze sourced from distant wildfires in Indonesia are expected to continue across Palau and Yap. Scattered showers and isolated thunderstorms are found across the far southern islands of Palau, closer to the buffer circulation, however this area of showers is not expected to build farther north. A broader area of showers and a few thunderstorms are spread out across across Chuuk State and eastern Yap State due to moderate northwesterly convergence alongside the monsoon trough and a monsoon disturbance between Chuuk and Pohnpei. The monsoon disturbance is expected to move in a general west-northwest direction in the coming days and remain fairly disorganized, however, the strengthening convergence along the western and southern peripheries will be the focus of unsettled weather for the region this week. As the disturbance shifts west- northwestward, scattered showers and isolated thunderstorms are expected to continue through Monday at Chuuk. Showers then taper down to isolated to scattered Monday night and Tuesday. As the monsoon trough reorients itself this week, southwesterly convergence begins to set up across Chuuk around Wednesday, bringing another increase in scattered showers and isolated thunderstorms towards the latter half of week. Overall, Yap and Palau remain on the outskirts of this developing pattern, but depending on the proximity of the monsoon trough, low-end scattered showers may return to Yap Wednesday and Thursday, and to Palau sometime late week. Latest altimetry data shows combined seas have remain steady at 2 to 4 feet near Palau and Yap, and 3 to 5 feet at Chuuk. Benign marine conditions are expected to continue over the next several days, with seas increasing to 4 to 6 feet around Thursday for Chuuk coastal waters due to an increase in south to southeast swell. Light to gentle winds persist over the next several days with an increase in gentle to moderate southwesterly winds at Chuuk starting Wednesday. && .GUM WATCHES/WARNINGS/ADVISORIES... GU...None. MP...None. Marianas Waters...None. && $$ Marianas: Mesa East Micronesia: Kleeschulte West Micronesia: Cruz