Andrew Austin-Adler, a student meteorologist specializing in tropical cyclones, said on X: "Strongest CPAC hurricane since WALAKA is inbound. Iona is on the fast track to reaching major hurricane strength - official forecast is 120mph which could be conservative."

Tropical Storm Keli, meanwhile, was located about 795 miles southeast of Honolulu with maximum sustained winds near 40 mph and higher gusts. Keli was moving west at 15 mph and is expected to maintain that general motion over the next couple of days.

Hurricane Iona was expected to move westward and does not pose any land threat to the Hawaiian Islands, forecasters said.