The JTWC reported that Yasa had peaked with 1-minute sustained wind speeds of , which made it equivalent to a Category 5 hurricane on the SSHWS during December 16. Later that day, the FMS reported that Yasa had peaked with 10-minute sustained wind speeds of , as well as a minimum pressure of , although it was operationally assessed at , and a minimum pressure of . The system subsequently started to weaken with its cloud tops starting to warm before Yasa made landfall in Bua Province on Vanua Levu as a Category 5 severe tropical cyclone, at around 06:00 UTC (18:00 FJT) on December 17.
