SYNOPTIC DISCUSSION

FRIDAY 03rd APRIL 2026 PM SHIFT

TONIGHT AND TOMORROW:

A moist easterly wind is the main weather driver for Samoa, holding the SPCZ together and its associated activity farther west. The sounding profile shows significant moisture and an elevated CAPE of 2455J/kg, supporting brief, localised thundery activity over leeward areas. A squall line formed this evening as southeast and easterly winds collided over Samoa, prompting these activities. Expect periods of cloudiness, isolated brief showers, and a few thunderstorms tonight and tomorrow.

FRIDAY THROUGH WEDNESDAY:

Global weather models show minimal precipitation for this outlook period, except Saturday, when a short-wave trough crosses Samoa, bringing showery conditions and localised afternoon convection with possible moderate to heavy showers over inland and highland areas. With little mid to upper-level forcing, cloud development will mainly follow daily heating. At the same time, models predict the development of lower-level circulations northwest of Samoa, which are expected to become TCs next week. These systems are likely to intensify south of Fiji and later further south of the Solomon Islands. They pose no threat to Samoa, as a strengthening high-pressure ridge will dominate the eastern Southwest Pacific, and the SPCZ, together with embedded lower-level circulations, will shift westward and away from Samoa.

MARINE OUTLOOK:

Marine observations from King Poloa and Aunu’u wave buoys and altimeter data show wave and swell heights remain below 2 metres, posing no imminent threat to Samoa’s marine waters. Global wave models indicate wave activity will stay below the 2.5-metre advisory threshold.

ADVISORIES/WARNINGS:

NONE

Weather Duty Team:

MJS, Andrew Sofeni, Punipuao Huch & Chris Baker