SYNOPTIC DISCUSSION
THURSDAY 09th APRIL 2026 PM SHIFT
TONIGHT INTO TOMORROW:
Recent satellite data indicate mid to high level cloud dominating over the area – fewer low level clouds streams over the group, despite lingering instability indicated by sounding profile. Light and variable winds remains prevalent – enabling the coupling of solar radiation and existing instability to bring about localized convections observed earlier in the day. The absence of the sun’s energy, then enables the dominance of the remnants of TC Vaianu’s feeding bands to provide cloudiness and a few isolated showery periods for Samoa. Therefore, for tonight and tomorrow anticipate similar conditions across the islands.
SATURDAY THROUGH THURSDAY:
The movement of TC Vaianu through the mid-latitudes allows the abovementioned ridge to direct the easterlies across the forecast area in the upcoming weekend. Thus, maintaining stable weather apart from passing showers for Saturday and Monday of the new week. However, there is an upper trough predicted to landfall for the start of next week which may increase uplifting of air parcels especially during the afternoon time. There are also higher levels of PWAT hinted by the ECMWF model which may linger over the trade wind regime for the first half of this outlook period. The currently active TC systems [TC Maila and TC Vaianu] are predicted to weaken through the weekend and will pose NO threat to Samoa’s area of responsibility.
MARINE OUTLOOK:
Recent marine observations from King Poloa, Aunu’u wave buoys, and altimeter data indicate that wave and swell heights are fluctuating around 2 metres. Global wave models project that wave activity to increase slightly more than 2.5 metres over Samoa’s southern marine waters for tomorrow into Monday. During this period, there is a low probability of significant wave heights entering Samoa’s northern marine waters for this outlook period.
ADVISORIES/WARNINGS:
NONE
Weather Duty Team:
MJS, Sasamamao Kalolo, Christopher Baker & Ne’emia Tutasi