FORECAST DISCUSSION

TUESDAY 25thJANUARY 2022 – AM SHIFT

TODAY:

Current satellite loops shows the edge of the South Pacific Convergence Zone remain stationary to the north of the island group. the strengthening of the ridge of high pressure tends to hold the aforementioned system to the north. The sounding profile of the atmosphere show unstable conditions with fresh to strong Westerly winds in the mid-level. This leads to shallow convective activities within the nowcast period. The absence of the upper-level divergence over the area limited cloud development. Therefore, expect some showers with few thunderstorms likely depending on surface heating.

THURSDAY THROUGH MONDAY:

Global models predicted a weak low-pressure circulation developing just northwest of the Samoan Islands by early Wednesday troughing south-eastward over Samoa. This trough will be the rainmaker for Wednesday and Thursday and the likelihood of re-issuing the SWI for heavy rain is moderate at this stage. A strong surface-mid level ridge is predicted to develop just southeast of Tahiti and build westward, thus allowing fresh to strong northeast winds to impact the island chain by Friday into Sunday.   

MARINE:

The latest wave and swell observations indicate wave heights below the advisory threshold as strong winds moves further northeast. However, another area of fresh winds are predicted to enter the forecast zone by Thursday and may elevate waves above 2.5 metres. Will continue monitoring this situation and update accordingly.

WARNING/ADVISORIES:

NONE

TEAM AM-SHIFT:

E. Toluono, A. Liu & I. Tuatipi.