[8][9] The depression moved south-eastwards at first, before it turned southwestwards through Temotu Province towards Vanuatu, which prompted the FMS to start issuing special weather bulletins for the island nation during November 13.
[9] Within Vanuatu, preparations had been completed for a storm-force cyclone, before the FMS issued a hurricane warning at 18:15 VUT (07:15 UTC) on November 15, which prompted a higher response from the residents of the island nation.
[8] Overall, the system had a minimal impact on the island nation, with damage reported to crops and bush houses, while heavy rain associated with the cyclone helped break a long dry spell of weather in Vanuatu.
[4] Vania also brought rain to parts of Fiji that were responsible for severe flooding within Tailevu Province, which in turn caused over 100 hectares (250 acres) of crops to be damaged and the deaths of a significant number of farm animals.
[14][11] At this time, the system was located about 110 km (70 mi) to the northeast of Labasa, Fiji, and was estimated to have maximum 1-minute sustained wind speeds of 65 km/h (40 mph).
[11][5] During January 1, TCWC Nadi reported that the depression had developed into a Category 1 tropical cyclone and named it William as it passed near the Cook Island of Autitaki.
[5] During the next day, William subsequently slowly accelerated as it passed near to or over several other Cook Islands and intensified into a Category 2 tropical cyclone.
[16] Later that day, both the NPMOC and the FMS estimated that the system had peaked just below hurricane-force with winds of 110 km/h (70 mph) as it left the tropics and transitioned into an extratropical cyclone.
[15] Throughout the Southern Cook Islands, it caused around US$2.5 million worth of damage to crops, buildings, and coconut trees and destroyed a causeway to a tourist resort on Aitutaki.
[19] Over the next couple of days, the system moved south-eastwards away from Fiji, before it was classified as Tropical Cyclone 18P by the NPMOC during March 16, while it was located about 365 km (225 mi) to the south-east of Nuku'alofa in Tonga.
[20] While 18P existed over the South Pacific, a trough of low pressure impacted Fiji, which caused moderate to heavy rain and flooding to be reported in Labasa and Nadi, while over 250 tonnes of canne were destroyed.