Updated 35 minutes ago

Map: Cairns 4870 Related Story: Cyclone to bring '24 hours of terror' Related Story: Cairns, Townsville step up cyclone preparations Related Story: North-west Qld prepares for Yasi Category five Cyclone Yasi has knocked out the weather bureau's radar system on Willis Island, about 450 kilometres east of Cairns in far north Queensland.

The weather bureau's radar and wind speed measurements on the island failed just before 9am (AEST).

The bureau says the maximum wind speed recorded before the equipment went down was 185 kilometres an hour.

Three weather observers and a technician left the island yesterday.