Although it was traveling at a quick pace, the storm gained organization and reached its peak intensity with winds of 85 km/h (53 mph) the following day.

However, the increasing forward motion of the storm, combined with strengthening wind shear, caused Tam to rapidly weaken on January 14.

[1] The system, designated 04F by the Regional Specialized Meteorological Centre (RSMC) in Nadi, Fiji tracked slowly towards the west.

[2] Although the depression was located within an area of low wind shear, little intensification occurred, as a lack of low-level moisture hindered the development of deep convection.

[1] By January 9, shower and thunderstorm activity associated with the disturbance increased as it began to interact with the South Pacific Convergence Zone.

[2] However, with both wind shear and the forward motion of the storm continuing to increase, convection rapidly became dislocated from the center.

[3] Around 0000 UTC on January 14, Tam entered the area of responsibility of the Tropical Cyclone Warning Centre in Wellington, New Zealand.

[1] As Tam was developing, residents attempted to evacuate the island by plane, with the primary target of Fiji.

[5][6] Early the next day RSMC Nadi placed northern Tonga under a tropical cyclone gale warning.