SYNOPTIC DISCUSSION

THURSDAY 02nd APRIL 2026 AM SHIFT

REST OF TODAY:

Remnants of the South Pacific Convergence Zone (SPCZ) continue to generate intermittent showers, gusty winds, and thunderstorms over Samoa, despite the system's southward progression. As a result, Heavy Rain and Flood Warnings have been downgraded to advisories, although elevated atmospheric moisture remains in the region. Sunny intervals are forecast for today, with the potential for brief periods of heavy rainfall and a lower risk of flooding compared to previous days. Precipitable water (PWAT) is currently 55.69 mm, indicating a slight increase in atmospheric moisture over the past 12 hours. The axis of the system has shifted further south, concentrating moisture away from Samoa; however, moisture continues to accumulate to the north due to prevailing moist northerly winds.

THURSDAY THROUGH TUESDAY:

Global weather models suggest that improving weather conditions will take over during this outlook period as the east to northeast winds predominate across Samoa. Showery conditions are expected with localised afternoon convective storms likely. The lack of a significant mid to upper level forcing, suggests that cloud development will be largely diurnally driven throughout this outlook period. In addition, model consensus hints at a low-pressure system to develop over the northeast of Fiji by Friday and may deepen as it tracks to the east of Vanuatu, then through the south of Fiji towards the new week. The system is not expected to directly affect Samoa as per the latest model runs.

MARINE OUTLOOK:

The latest marine observations from King Poloa and Aunu’u wave buoys, as well as altimeter data, continue to reveal that wave and swell heights fluctuate around 2 metres, which suggests no imminent threat across Samoa’s marine waters. Global wave models suggest that wave activity will remain below the advisory threshold of 2.5 metres throughout this outlook period.

ADVISORIES/WARNINGS:

CANCELLED: HEAVY RAIN WARNING

CANCELLED: FLOOD WARNING

VALID: FLOOD ADVISORY

VALID: HEAVY RAIN ADVISORY

Weather Duty Team:

MJS, Albert Niko, Punipuao Huch & Andrew Sofeni