FORECAST DISCUSSION

SUNDAY 03rd MAY 2026 AM SHIFT  

TODAY INTO TONIGHT:

The easterlies still prevails across Samoa, with a few fair weather cumulus clouds streaming along the wind flow. Thus, mostly cloud free in the morning, this supports surface heating over the landscape. So, the total precipitable water channel and sounding profile both revealed sufficient moisture content, mid dry slot, weak wind structure, weak steering wind flow, and moderate instability. Thus, such are observed mesoscale weather patterns, with the aid of topographic effect, would promote afternoon shower, a few thunderstorms but are being suppress and short-lived as the subsidence along with the strong wind shear environment. For tonight, expect previously stated mean wind flow to persist.

MONDAY THROUGH FRIDAY:

Global weather models suggest that the South Pacific Convergence Zone (SPCZ) may reside near south of Samoa during the new week, and is likely to extend rainfall activities over the group with periods of possible isolated heavy downpours. The steering flow during this period is expected to remain light to gentle, suggesting the lack of vertical disruption in cloud development. Additionally, strong southwest to westerly winds aloft may persist over the region, and 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. Global wave models suggest that a southerly combined wind waves and swells may approach the group and likely affect the southern marine waters from Wednesday. These wave activities may exceed the advisory threshold during this period.

ADVISORIES/WARNINGS:

NONE

Weather Duty Team:

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