FORECAST DISCUSSION

SUNDAY 24th MAY 2026 PM SHIFT

TONIGHT AND TOMORROW:

Fair weather remains over the group, as indicated by the latest observations, with fewer clouds and mostly sunny periods. However, conditions are expected to change, as a convergence zone is forecast to move north of the group later tomorrow evening. This system is expected to bring increased cloud cover and may result in periods of scattered rain, some potentially heavy, likely to descend near the north of the group later in the evening or towards the night. Therefore, this change may prompt the issuance of a Heavy Rain Advisory for all land areas later tomorrow, prior to the arrival of severe weather activities.

OUTLOOK: MONDAY THROUGH FRIDAY

Global weather models suggest that the southeasterly winds will remain dominant through at least Sunday as a high-pressure ridge extends from the south, keeping fair weather conditions over the group. A convergence zone is forecast to establish to the north of Samoa by Monday and may move over the group on Tuesday with the potential for heavy downpours. The weather system is expected to linger over the group through at least Thursday, with a low-pressure system passing across Tonga over the week. In addition, an upper trough is forecast to pass just south of the group from Tuesday, and is likely to enhance convective storm growth and development during this period.

MARINE OUTLOOK:

The latest marine observations continue to indicate that wave heights are fluctuating below the advisory threshold of 2.5 metres across Samoa’s marine waters. Global wave models suggest that wave activities may occasionally exceed 2.5 metres particularly across the southern marine waters during the weekend, due to a southerly swell event.

ADVISORIES AND WARNINGS:

NONE

Weather Duty Team:

MJS, A. Niko, S. Tavana & N. Tutasi.