Area Forecast Discussion

Marianas Update

No changes for the Marianas, which remain in a dry trade-wind regime. Light to gentle east winds will combine with seas 3 to 4 feet to make for benign sea conditions, which are likely to last at least through this week. The fire danger is low, but it could become moderate on Tuesday.

Eastern Micronesia Update

No changes for Pohnpei or Majuro. For Kosrae, just corrected the sky and weather relationship for today through Monday night, by making the showers isolated today when the clouds to the east are mostly cirrus. Then, for tonight through Monday night, made the showers scattered while the skies became mostly cloudy. Winds of 5 to 10 knots and seas of 3 to 4 feet will lead to benign marine conditions through the entire forecast period.

Western Micronesia Update

No changes for Western Micronesia, except to reduce high temperatures today at Chuuk. 89 degrees and a 50 percent chance of showers usually don't mix, so lowered the highs to 88 degrees. Winds of 5 to 10 knots and seas of 3 to 4 feet will lead to benign marine conditions through the entire forecast period.

Prev discussion

/issued 511 PM ChST Sat Jun 6 2026/

Marianas Synopsis... Satellite imagery reveals partly cloudy skies and isolated showers across the Marianas this afternoon. Combined seas are between 3 to 4 feet and a moderate risk of rip currents exists along north- and east-facing reefs.

Discussion... A shallow trade-wind trough has produced partly cloudy skies for most of the Marianas, especially over southern Guam and adjacent coastal waters as the reinvigorated moisture interacts with island-effect heating. Showers are isolated in coverage and timing, so PoPs were kept at 20 percent for tonight as the drier airmass persists across the region for the rest of the weekend. Winds are being observed between 10 to 15 mph and are expected to continue through the rest of the forecast period. As we enter the new week, a broad surface trough may track towards the Marianas as the high pressure ridge retracts to the north. The region may see scattered showers and mostly cloudy skies building in starting Monday afternoon. Model guidance is in much disagreement on the intensity and timing of this trough, so there is a slight possibility of isolated thunderstorms spatially limited to Guam and adjacent coastal waters for the same time period. The dry trade-wind regime could possibly make a return starting midweek.

Marine... For this forecast period, a secondary, weak, northerly swell was introduced as significant weather features traverse across the mid- latitudes far to the north. These swell heights are expected to remain limited to 2 to 3 ft in the first half of next week, becoming negligent in the second half. Thus, combined seas will stay within the 3 to 4 ft range, possibly peaking to 5 ft around Monday night. Buoy and altimetry data currently support sea heights capable of producing 3 to 5 ft surf along north- and east-facing reefs, so there remains a moderate risk of rip currents. These surf conditions are expected to continue at least for the next several days.

Eastern Micronesia... A surface trough has amplified today between Kosrae and Pohnpei, and this will keep scattered showers and isolated thunderstorms going for Pohnpei through Monday. At Kosrae, with the trough moving away you can expect just isolated showers tonight. However, an area of enhanced surface convergence to your east, associated with the re- invigorating ITCZ (Inter-Tropical Convergence Zone) will bring scattered showers and a few thunderstorms back into your forecast as early as tomorrow (Sunday). This will then continue through Monday before the activity diminishes again. Finally at Majuro, a surface trough just to the west of you is close enough to keep scattered showers going in your forecast tonight. Then, a decrease in shower coverage is anticipated for Sunday and Sunday night, before additional areas of enhanced convergence and/or surface troughs once again increase your rainfall potential Monday onward.

For the mariners, look for light to gentle winds to persist through the forecast period, with seas of 3 to 5 feet continuing.

Western Micronesia... Satellite imagery shows scattered showers over Weno and Chuuk State, and across western Yap State. Isolated showers are seen across Yap Proper and Palau. Altimetry shows combined seas between 2 and 5 feet across the region.

The main two weather features impacting western Micronesia are the Near Equatorial Trough (NET) and a weak circulation. The NET extended northward overnight, where it meets a weak circulation south of Pohnpei, and a weak circulation northeast of Weno. Weno and Chuuk State continue to be within the region of convergence, which is keeping shower coverage scattered through the next several days.

A weak surface low was located near 7N140E or southeast of Yap Proper. Convection has been ongoing and well organized today with continued improvements this afternoon. This current circulation appears to be over performing compared to the previous ECMWF and GFS solutions. Although the environment is favorable for development, guidance shows a weakening of the westerly winds south of Palau. This limits the storm's potential to wind itself up into a stronger system. Nonetheless, scattered to numerous rainfall is expected for Yap over the next few days. Palau will generally see isolated to scattered showers through the period while on the fringe of the circulation. If westerly winds remain stronger than modeled, then we will need to watch this system for further development.

Overall, little to no changes to the marine forecast from the previous package. Combined seas are between 2 and 5 feet and look to remain benign through the period.

GUM WATCHES / WARNINGS / ADVISORIES

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