Area Forecast Discussion

Marianas Synopsis

Partly cloudy skies with isolated showers continue across the Marianas for the remainder of the week. Increased showers and strengthening trade winds are possible early next week. Buoys show seas are 4 to 6 feet.

Discussion

A dissolving frontal boundary exists east of Guam and is advecting west with the trade winds, but the dry regime will keep isolated showers and partly cloudy skies over the Marianas for the remainder of the week. Over the weekend, a high pressure cell could traverse eastward from Japan across the mid-latitudes, so the possibility of moderate to fresh trade winds has remained due to the stronger pressure gradient. Additionally, model guidance shows a trough moving in from the east, possibly bringing low-end scattered showers to the Marianas early next week.

Marine

Combined seas of 4 to 6 feet are expected to increase a foot Thursday before tapering back down thereafter. Seas are likely to persist until early next week, once seas begin to increase again due to strengthening trade swell and localized wind waves. A moderate risk of rip currents is expected along north and east facing reefs of the Marianas for at least the next several days. Surf is expected to persist at current levels until early next week, when it may increase an and additional few feet along north and east facing reefs once the aforementioned swell and wind waves increase.

Eastern Micronesia

Troughing will continue to impact Kosrae and Pohnpei through tonight, bringing periods of scattered showers and isolated thunderstorms. Conditions should briefly improve on Thursday and continue into Friday, with only isolated to low-end scattered showers and some thunderstorms expected as a trade-wind pattern develops across eastern Micronesia. Northeast to east winds will increase starting late Thursday as the pressure gradient tightens. Moderate to fresh winds will be possible at all forecast points from Friday through the weekend with the strongest winds at Majuro. Shower chances will increase starting late on Friday as the ITCZ shifts northward and a series of trade-wind troughs move through the region. Scattered to low-end numerous showers and isolated thunderstorms can be expected this weekend.

The coastal waters of Pohnpei and Kosrae consist of a longer-period north swell and a diminishing, longer-period northwest swell. Elevated surf will continue to be possible along north-facing reefs of both Kosrae and Pohnpei through tonight. Seas around Majuro consists of the longer-period north swell and a short-period east swell. Combined seas of 4 to 6 feet will increase by a foot or two at all sites through the weekend as a trade swell builds into eastern Micronesia starting with the Marshall Islands. Elevated to possibly hazardous surf will be possible at Pohnpei and Kosrae this weekend as the trade swell builds. Seas up to 8 feet will be possible at Majuro this weekend.

Western Micronesia

The leading edge of the of the ITCZ fragment with embedded troughs is moving into Chuuk State. This feature will bring an unsettled weather pattern to Chuuk through early next week. Scattered showers and isolated thunderstorms are expected through this time frame. Estimated rain fall totals are expected to be within the range of 0.5 to 1.0 inches per day through the beginning of next week.

Over in Yap and Palau, a drier regime has set up and is expected to remain for the next day or so. Then, showers are expected to return around Thursday night to Friday as few troughs make their way across eastern Yap State. These showers may remain in the area through the weekend.

Altimetry shows combined seas of 4 to 7 feet across the region. Winds are expected to be light to moderate through the weekend. Overall fairly benign seas are expected.

GUM WATCHES / WARNINGS / ADVISORIES

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