WEDNESDAY 24th JANUARY 2018 AM
Latest satellite loop images of this morning shows convective cloud band to the west of Samoa extending Southeastward. Surface streamline at1200utc analysed a trough with a weak convergence zone to the south west of the group. This weather system links to a cyclonic circulation to the West of the forecast zone. An upper-level trough continues to maintain the development of the system South . Sounding indices indicates an unstable atmosphere. An upper-level ridge directs a South westerlies wind aloft, and upper-level moisture providing some showery activities within the nowcast period. There fore: cloudy conditions maintains with some showery activities for nowcast periods with moderate falls and few thunderstorms before easing in the evening. Few Northeasterly winds.
THURSDAY THROUGH SUNDAY:
Another weak convergence zone to the East associated with a trough behind it will provide some instability by Thursday and Friday. Along this
trough a weak low is expected to develop Southeast of Pago in the latter part of the outlook period with a few showery activities. Latest model
run predicted another low to develop to the West of New Caledonia and is expected to develop by Sunday and drifts East Southeastward.
A ridge far Northeast maintained moderate Easterlies for Samoan waters throughout the outlook period. Apart from Saturday a wind change is
expected to turn Northwest due to the aforementioned weak low to the Southeast. Aunu'u wave bouy recorded sustained wave height of 5-7ft. And is expected to remain below the advisory threshold for the duration of this outlook period.