FORECAST DISCUSSION

WEDNESDAY 29th APRIL 2026 PM SHIFT  

TONIGHT INTO TOMORROW:

Samoa’s weather conditions were largely diurnal driven, where the easterlies continue to prevail, with associated brief showers along the wind flow, with short-lived afternoon convective clouds mainly over highlands and the western district of both islands. Atmospheric conditions were evidently proven through the sounding profile, depicted low-level moisture advection, mid-to-upper dry slot that coincides with water vapor imageries and moderate instability. Furthermore, present positive vorticity showcase anticyclonic rotation, an implication of subsidence aloft, which restrict cloud formation. Hence, satellite imageries captured convective clouds with short-lived lightening. For tomorrow, there’s a greater chance for afternoon showery and thundery activities due to the topographic effects.

FRIDAY THROUGH TUESDAY:

Generally, model consensus suggested the wind flow to veer east-to-southeast where as the trough of low pressure slowly descends over the area by late Friday through Saturday, providing rainfall activities with a potential for moderate to heavy falls. Then on Sunday, the system slowly drifted to the west, swerving the wind flow to be northeast, as a ridge of high pressure to the east of Samoa, extends to northwestward. Then expect the trade wind regime prevails on Monday through Tuesday, with passing showers. The lack of a significant upper-level forcing suggests that convective storms will be largely diurnally driven during this period.

MARINE OUTLOOK:

The latest marine observations from Aunu’u and King Poloa wave buoys indicate that wave heights continue to fluctuate below the advisory threshold of 2.5 metres. Wave watch models suggest that wave activities will persist well below the advisory threshold for the rest of this outlook period.

ADVISORIES/WARNINGS:

NONE

Weather Duty Team:

A. Liu, A. Sofeni, C. Baker & N. Tutasi.