MONDAY 18th JANUARY 2021 (AM SHIFT)
Latest satellite imageries shows a cloud band just to the Northeast of the group that is associated with a trough of low pressure as analyzed by surface streamline analysis. Meanwhile, only a few stable low-level clouds are visible streaming along the Easterly wind flow over Samoa. A deep Easterly wind flow affects low-mid levels of the atmosphere with a strong south-easterly winds aloft could inhibit convective cloud developments within the nowcast period. Meanwhile, global models depicted few rainfall activities within the nowcast period along the Easterly wind flow. Therefore, expect cloudy periods with isolated brief showers.
TUESDAY THROUGH SUNDAY
A trough of low pressure system is expected to provide showers activities for the islands in the midweek with light Northeasterly winds. A trough of low pressure associated is expected to approach the group by Thursday. Models predicts the a persisting ridge of high pressure to become the main weather driver for the remainder of the outlook period while a convergence zone will lie to the Southwest of the group.
MARINE OBSERVATION & OUTLOOK
Latest wave observations shows significant wave heights just above 1.5-2 metres. Long period travelling Northerly swells are likely to reach our Northern open waters by Tuesday. However; a sub-tropical ridge may extend from the Southwest and elevated swells and wave activity is likely to impact the islands towards the end of the week.
WARNINGS AND ADVISORIES
A.Niko & E.Toluono