SYNOPTIC DISCUSSION
TUESDAY 24th MARCH 2026 PM SHIFT

TONIGHT INTO TOMORROW:

A collection of satellite data revealed convective clouds developed within the vicinity early afternoon, which generated periods of brief moderate falls, as the moist easterlies remain prevalent across Samoa. Such weather conditions were captured through the radiosonde profile, which indicated low-level moisture content, weakening wind strength, and instability. Further, although no upper mechanism but weak wind shear environment promotes cloud formation with a short life span. So, the air temperature decreases in the evening, that correspond to the easing of showery and thundery activities with partial cloudiness in some areas. Later, the wind flow slowly veered southeast, prevailing now over the area of concern, since the well-established area of high pressure stationed east of New Zealand gradually moved to the east. For tomorrow, the movement of the previously stated area of high pressure, which maintains the wind flow across the vicinity, with possible diurnal weather phenomena with thunderstorms in some areas. Eventually, the wind flow will slowly become light and variable as a trough of low pressure moves from the north

THURSDAY THROUGH MONDAY:

On Thursday through Friday, the trough of low pressure system gradually shifts to the south as a ridge of high pressure extends to the north of Samoa, causing the wind direction to veer north-to-northwest. At this point, model consensus suggested showery and thundery activities, regardless of a broad area of low pressure that may remain stationary south of the forecast zone. However, there’s a probable chance these forecasted winds may steadily increase on Saturday through Monday, as an indication of a convergence zone that may provide accumulated rainfall with low severity. Furthermore, the upper atmosphere is likely composed of strong subsidence as the southeast-to-south wind flow may prevail over the area of interest. So, it is crucial to monitor and update accordingly based on the latest forecast weather models.

MARINE OUTLOOK:

As of now, the marine observational data continues to indicate that wave and swell heights across Samoa’s water areas, which is still remain well below 2 metres. This wave trend is expected to persist throughout the outlook period based on the global wave model.

ADVISORIES/WARNINGS:
NONE

Weather Duty Team:
A. Liu, S. Kalolo, S. Maualaivao, & A. Uili.