SYNOPTIC DISCUSSION
SATURDAY 06th DECEMBER 2025 PM SHIFT
TONIGHT INTO TOMORROW:
Samoa’s experienced fine weather, as the easterly wind flow prevails except cumulus congestus formed mainly over the highlands due to the diurnal weather pattern. The radiosonde profile depicted a low-level inversion, in sufficient moisture content and instability. In addition, a present upper convergence an implication of sinking air, which suppressed vertical cloud growth. Thus, it lead to the formation of low-to-mid level clouds over central windward areas and slowly fades later afternoon.
Tomorrow, the weather model forecasted a ridge of high pressure builds from the east close to the Northern Cooks, extends northwestward. This change the mean wind flow veering east-to-northeast with wind strength to be light across the area of responsibility. Thus it support, orographic precipitation over elevated locations.
MONDAY THROUGH FRIDAY:
A collection of weather model, the mean wind flow swerve northeast-to-north as a low-level circulation formed slightly to the southeast of Fiji tracked southward on Monday. This illustrate the SPCZ may linger to the west, yet along the mean wind flow there’s possibly a convergence zone likely to appear slightly to the west and it may gradually reside near the area of forecast on Tuesday through Wednesday. In time, the forecasted SPCZ concentrated to the west, as the wind flow veer from the east Thursday through Friday, with periods of showers along the wind flow. The lack of a significant upper-level trough during this outlook period would expect shallow activities to the low-to-mid level. Nevertheless, ensemble models suggest the possibility of heavy rainfall in the upcoming week.
MARINE OUTLOOK:
Recent marine observations reveal that wave and swell heights are varying beneath the advisory threshold of 2.5 meters. However, global wave models indicate that north to northeast swells are expected to impact Samoa's marine waters by the middle of the upcoming week, albeit with a low likelihood of occurrence.
ADVISORIES/WARNINGS:
NONE
Weather Duty Team:
A. Liu, A. Niko, S. Maualaivao, & C. Baker.