SYNOPTIC DISCUSSION

SAURDAY 24TH JANUARY 2026 AM SHIFT

TODAY:

The active convergence zone remains within the vicinity of Samoa and continues to provide unstable weather conditions over the islands. Thus, sustains a high risk of flooding for all major rivers and vulnerable low-lying areas. This system is likely maintaining severe weather conditions over the country for today into Monday. Therefore, expect scattered rain with possible heavy falls in some areas, gusty periods and thunderstorms for today. Such weather changes warrant the upgrading of the Flood Advisory to a Warning category with the continuation of other highlighted Warning and Advisory for Samoa. In addition, the abovementioned convergence zone will generate wave heights exceeding 3 metres or more for today into the new week. Expect widespread rain with periods of heavy falls, few thunderstorms with strong and gusty winds of up to 45 – 55 km/h especially over highland areas.

SUNDAY THROUGH FRIDAY:

Deteriorating weather conditions are consistently predicted by NWP models to persist over the forecast zone throughout the outlook period. Models are in good agreement about the location of the SPCZ and its expected northward fluctuation and southward over the island during the weekend and the start of the new week. It is anticipated that the convergence zone may remain to the north through Monday before descending over the area by Tuesday, however, high uncertainty for the meantime. The coupling of the MJO with upper-level enhancement features is likely to sustain the activeness of the SPCZ, which may trigger the formation of embedded low-level circulation, as indicated by the latest weather models. Model consensus places a broad area of low pressure just south of Samoa, which is likely to draw abundant moisture over the country by midweek, along with strengthening northwesterly wind flow.

MARINE OUTLOOK:

The latest wave observations from Aunu’u and King-Poloa buoy signify wave heights exceeding 3 metres. This is mainly due to the convergence zone directing northwesterly winds that reach up to 35 – 40 kph and thus elevated wave activities over our coastal and open waters. The global wave models forecast this system to likely maintain these high wave activities throughout next week.

ADVISORIES/WARNINGS:

VALID: HEAVY RAIN WARNING

VALID: FLOOD WARNING

VALID: WIND ADVISORY

VALID: MARINE ADVISORY

Weather Duty Team:

A.N, A.S & A.UILI.