FORECAST DISCUSSION

SUNDAY 12thAPRIL 2026 – P.M SHIFT

TONIGHT & TOMORROW:

A moist easterly wind flow remains prevalent across Samoa as a surface trough lies west of the group. Partly cloudy conditions with a few single-cell convective clouds were depicted over the Va-i-Nuu and southern parts of Savaii in the late afternoon as a result of the unstable atmosphere hinted over the sounding profile. Sufficient moisture and availability of lifting contribute to the onset of these afternoon convections further enhanced by the strong solar heating during daytime with the sea breeze assistance. Weather charts updated by Fiji, Hawaii as well as New Zealand Met Services portray the influence of the dominance Easterlies over our AOR. Satellite animation showcase a slight break in showery activities with decrease sky cover dominated by upper level clouds observed at approximately 16000ft according to METAR reports from the Faleolo aerodrome. Trade wind regime will continue to take over for tonight through tomorrow with isolated showers anticipated in the latter hours of tomorrow.

TUESDAY THROUGH SATURDAY:

Global weather models suggest that the easterly trade winds will predominate Samoa throughout this outlook period, with a series of short-wave troughs passing across the group. This synoptic pattern may induce showery conditions over the forecast area, with the potential for moderate to heavy falls in some areas. The easterly steering flow is forecast to be gentle to moderate during this period, suggesting minimal vertical disruption to convective storm development and growth. In addition, an upper trough approaching from the west is expected to lie near west of Samoa by Monday, providing some favourable aloft that may enhance cloud development through at least Tuesday. This upper-level system is forecast to exit through the north by Wednesday, allowing southerly winds aloft to dominate in the remaining days of the outlook period.

MARINE OUTLOOK:

The latest marine observations from Aunu’u and King Poloa wave buoys indicate that wave heights occasionally exceeded 2.5 metres over the past 12 hours. These wave activities may continue to slightly increase above 2.5 metres mainly over the southern marine waters from Saturday through at least Monday of the new week. During this outlook period, there is a low probability of significant wave heights entering the northern marine waters. Although this may be the case, activities may not pose serious wave-related hazards to the group’s marine waters.

ADVISORIES/WARNINGS:

NONE

Weather Duty Team:

Gafa, Niko, Maualaivao & Uili.