Area Forecast Discussion
Issued by NWS Tiyan, Guam
Issued by NWS Tiyan, Guam
977 FXPQ50 PGUM 030801 AFDGUM Area Forecast Discussion National Weather Service Tiyan GU 601 PM ChST Wed Sep 3 2025 .Marianas Synopsis... Satellite imagery shows mostly cloudy skies, while radar shows stratified showers over the Marianas. Buoys indicate seas are 2 to 3 feet. && .Discussion... A trough is slowly moving towards the Marianas. This will bring scattered showers to the region through the end of the week. Radar shows showers diminishing over the islands, however, this won`t last. The winds are expected to converge, sparking more showers tonight. This convergence is anticipated to last through the rest of the week. Once this trough and convergences passes, a ridge is anticipated to build in, bringing in some drier more pleasant weather. && .Marine... Light to moderate winds will persist through Thursday night, then becoming light to gentle. Seas of 3 to 4 feet could diminish slightly to between 2 and 3 feet on Friday. There is a low risk of rip currents along all reefs. Surf and swell are expected to remain low through the end of the week. The lightning risk for Guam and Rota has diminished and is not anticipated to return until the weekend. The lightning risk for Tinian and Saipan is expected to return Thursday as moderate and remain through the weekend. && .Eastern Micronesia... A series of troughs will continue to move across the region through early next week. Due to the lack of a coherent ITCZ, these troughs will be the main driver for increasing rainfall potential, with winds over the waters also in the gentle to moderate range as these features cross the area. Otherwise, look for isolated showers to be the most we can hope for. Winds will be in the light to gentle range outside of trough passage, with seas of 3 to 5 feet expected. && .Western Micronesia... After tonight`s patchy showers and some thunderstorms at Palau and Yap, a mostly dry weather regime is expected to ensue at all three locations, as trades return and most of the convection remains upstream and northwest of the region. Gentle to moderate trade winds are expected for much of the forecast period, which will continue to keep the easterly swell fairly weak, producing only 3 to 4 foot seas across much of the region. && .GUM WATCHES/WARNINGS/ADVISORIES... GU...None. MP...None. Marianas Waters...None. && $$ Marianas: Bowsher East Micronesia: Doll West Micronesia: Montvila