textproduct: Tiyan

Marianas Synopsis

Satellite observations show partly to mostly cloudy skies across the Marianas with radar observations showing isolated showers. Ipan and Ritidian Buoy show combined seas between 3 and 4 feet.

Discussion

Scattered showers were seen across Rota earlier this morning before becoming isolated across the entire Marianas this afternoon. An uptick in showers are seen outside of the coastal waters moving into the Marianas late this afternoon. A weak trade-wind trough is currently moving across the region, which may allow for a brief uptick in shower activity this evening. Scattered showers will be possible through the evening before becoming isolated late tonight.

Both the GFS and ECMWF continue to show an increase in shower activity late Thursday night and into Friday for the Marianas. Modeled time heights show increased moisture through the column beginning Thursday night and persisting through Friday night. For now, scattered showers are only mentioned for daytime Friday, but an increase in PoPs may be necessary if models continue to trend towards wetter conditions.

Marine

Little change was made with the marine forecast with this package. Benign seas of 3 to 5 feet will persist through the week. A weak westerly to southwesterly monsoon swell will move into the region tonight. The rip current risk remains low across all reefs through at least Thursday night.

Eastern Micronesia

The trade flow has increased across eastern Micronesia and many surface disturbances are seen passing through the flow. The first trough has pushed west of Pohnpei. Another trough is passing north of Kosrae, while another one is pushing towards Majuro. More disturbances are seen east of the Date Line. This pattern will continue and periods of low-end scattered showers and isolated thunderstorms are expected at all three sites through early weekend. Showers and thunderstorm potential will increase at times over late weekend into next week as trade convergence or the Inter-Tropical Convergence Zone build in from the east. As a result, have increased the probability of precipitation (PoPs) up to 40 to 50 percent.

Outside of passing showers and thunderstorms, winds will generally be moderate with seas of 4 to 6 feet. Winds could become fresh and seas could rise up to 6 to 8 feet at times over the Majuro waters beginning this weekend as the trade flow will be a little stronger there.

Western Micronesia

Relatively drier weather continues across far western Micronesia this evening with a surface ridge in place over the area. However, a surface trough, currently centered over Eauripik in Yap State, looks to shift west-northwest through the region tonight through Thursday. Currently, scattered showers and isolated thunderstorms are seen along the trough axis, mainly near and northeast of Eauripik, and model guidance indicates this activity will spread westward, with showers increasing near Yap Proper starting late tonight, and then over the Republic of Palau tomorrow. The developing trough and associated trade-wind convergence look to maintain unsettled weather near Yap and Palau through the remainder of the week. Further east, satellite reveals fairly dry conditions over and immediately upstream of Chuuk Lagoon. Models indicate an increase in showers tonight as a subtle trough shifts westward across Chuuk State, with scattered showers expected to develop as trade-wind convergence builds near Weno. A combination of localized trade convergence and weak transiting troughs will keep shower chances at around 30 or 40 percent through the rest of the week.

Benign marine conditions continue. Combined seas of 2 to 4 feet are expected for Palau and Yap waters through the remainder of the week. Combined seas of 3 to 5 feet near Chuuk are expected to increase a foot or so by the end of the week with slightly higher trade swell and wind waves, with moderate to fresh trades expected over the next few days. Palau and Yap can expect mostly gentle, occasionally moderate easterly trades.

GUM WATCHES/WARNINGS/ADVISORIES

GU...None. MP...None. Marianas Waters...None.