FORECAST DISCUSSION

SUNDAY 19th APRIL 2026 – P.M SHIFT

TONIGHT:

Throughout the day, cloud accumulation and showery activity were observed in the late afternoon, a result of solar radiation aiding localised shallow, short-lived convective activity. Despite PWAT valued at 58.94mm, the existence of a dry air mass in the mid to upper atmosphere, as well as air subsidence, leads to improved conditions, typically resulting in clear skies, calm winds, as is now experienced across most of the group – therefore anticipate such conditions through the night and tomorrow.

MONDAY THROUGH SATURDAY:

A high-pressure system currently centred east of Australia is expected to move eastward, forcing the South Pacific Convergence Zone (SPCZ) eastward and away from the group. This synoptic weather pattern may allow the easterly trade wind regime to predominate throughout the week. At mid-levels, a high-pressure ridge may linger over the region during this outlook period, providing light steering flow, which suggests a lack of vertical disruption to convective development. In addition, westerly to southwesterly winds aloft are forecast to dominate the upper levels through at least Monday, before an upper high develops over the region. Models also hinted at a weak short-wave trough embedded along the easterly flow on Tuesday and Wednesday, which may bring some showery conditions across the group.

MARINE OUTLOOK:

The latest marine observations from Aunu’u and King Poloa wave buoys, as well as altimeter data, indicate that wave heights have fluctuated below 2 metres over the past 24 hours. These wave activities are forecast to persist throughout this outlook period, posing no significant wave-related hazards to the islands’ marine waters.

ADVISORIES/WARNINGS:

NONE

Weather Duty Team:

MJS, Le’asauaMaccariosAuvae, Lemauga Christopher Baker & Ne’emia Tutasi