FORECAST DISCUSSION

THURSDAY 30th APRIL 2026 PM SHIFT  

TONIGHT INTO TOMORROW:

Across the area of responsibility, the easterly wind flow remains prevalent with patches of fair weather cumulus along the wind flow. So, the sounding profile indicated present low-level moisture, mid-to-upper dry slot and weak instability. Furthermore, the water vapor imagery showcase dry airmass that coincides with the observed upper convergence that hinders vertical cloud growth. Therefore, the lack of cloud coverage, leads to maximum temperature that supports surface heating mainly over highlands. So, visible satellite channels captured cloud formation across the central and western areas of both islands, noted suppressed convective clouds or simply afternoon showers. As for tomorrow, the model consensus suggested the easterlies to dominate, with a trough of low pressure slowly moving westward near the area. There’s a probability of rainfall activities with a low potential of moderate falls. Yet such predictability is dependable through the real-time satellite data. So it is advisable to monitor for changes. 

SATURDAY THROUGH WEDNESDAY:

Numerical weather guidance, pinpointed that the previously stated surface trough of low pressure may linger slightly to the north of the area of forecast with it’s leading edge extends over Samoa, bringing cloudiness and showery activities with a potential of heavy falls later Saturday. Then on Sunday, the system slowly drifted to the west, swerving the wind flow to be northeastuntil Tuesday where the winds gradually weakens and become light and variable. Throughout this time frame, the model consensus, evinced no upper-level forcing, so the forecasted system focus merely at the surface only except an upper tough of low pressure moving from the west on Tuesday through Wednesday.

MARINE OUTLOOK:

The latest marine observations from Aunu’u and King Poloa wave buoys indicate that wave heights continue to fluctuate below the advisory threshold of 2.5 metres. Wave watch models suggest that wave activities will persist well below the advisory threshold for the rest of this outlook period.

ADVISORIES/WARNINGS:

NONE

Weather Duty Team:

A. Liu, A. Sofeni, C. Baker & A. U.