Area Forecast Discussion
Issued by NWS Tiyan, Guam
Issued by NWS Tiyan, Guam
679 FXPQ50 PGUM 151805 AFDGUM Area Forecast Discussion National Weather Service Tiyan GU 405 AM ChST Sun Jun 16 2024 .Marianas Synopsis... Satellite imagery is showing mostly cloudy skies across the Marianas. Scattered showers are seen near Guam, with mainly isolated showers for the CNMI. Latest altimetry passes and Ritidian buoy are showing combined seas of 4 to 6 feet. Gentle to moderate winds prevail. && .Discussion... As the weak trade disturbance continues to push west, drier air is moving into the Marianas. Low-end scattered showers over Guam diminish through the day. Otherwise, just expecting isolated trade showers. This drier pattern will continue through the week for the CNMI. On Monday and Monday night, a disturbance and moisture creep north and west out of Micronesia and push through the southern Marianas, bringing scattered showers to Guam but likely remaining south of Rota. By Tuesday, the dry pattern will return to Guam and continue through the rest of week. Some gusty winds are possible during the daytime hours today and tomorrow as the gradient is slightly tighter with the disturbances passing through. && .Marine/Surf... Gentle to moderate trade winds with some fresh gusts will prevail through the middle of next week. Combined seas of 5 and 7 feet today will slowly diminish by about 1 to 2 feet by the middle of next week as the trade swell subsides. Scattered showers and isolated thunderstorms will diminish across the southern Guam waters this afternoon. A moderate risk of rip currents is expected along north and especially east facing reefs through Monday. A low risk will remain along south and west facing reefs. Surf looks to decrease by the middle of next week, and the rip risk could become low along north facing reefs. && .Eastern Micronesia and Chuuk... Overall weather pattern consists of weak convergence and a series of trade-wind troughs moving through the region. An area of more notable trade convergence continues to generate scattered showers and isolated thunderstorms around Majuro, extending just east of Kosrae. Satellite trends shows a cluster of thunderstorms just east of Kosrae waters early this morning, so decided to add isolated thunderstorms back in for today. A TUTT low is north of the region and is expected to make its way towards Wake Island as the week progresses. The southern extent of the TUTT is expected to support convection in the region over the next several days as it drifts west-northwestward. Expecting this feature to link up with a trough slowly making its way through Kosrae tonight, Pohnpei Monday, then propagating towards Chuuk Tuesday. Majuro can still expect periods of scattered showers due to weak trade convergence and trade-wind troughs moving across the area. Models suggest a strengthening of an ITCZ pattern that will spread across the region from the Marshall Islands to Chuuk State late week and into the weekend. Combined seas are expected to be 3 to 5 feet across most of the region and up to 6 feet at Majuro over the next several days. Scatterometry data shows gentle to moderate winds across the region and mainly moderate winds across the Marshalls. Winds will generally be gentle to moderate this week, although the trades are expected to strengthen to moderate to fresh across Majuro late week. && .Western Micronesia for Palau and Yap... A broad surface trough extends into the region from the Philippines and curves southeastward, passing just southwest of Palau. Most of the convection in far western Micronesia clings along and south of the axis. Meanwhile, patchy showers are spread out across Yap Proper and Palau, where weak convergence follows behind this feature. An approaching trade-wind trough is expected to increase showers this afternoon for Yap and Monday for Palau. The surface trough is expected to linger in far western Micronesia, while trade-wind troughs continue to pile in from the east, creating periods of showery weather this week. Buoy and scatterometry data indicates seas around 2 to 4 feet and light to gentle winds for Palau and light to moderate winds around Yap. Expect benign marine conditions to continue through the week. && .GUM WATCHES/WARNINGS/ADVISORIES... GU...None. MP...None. Marianas Waters...None. && $$ Marianas: Slagle Micronesia: Cruz