On 20 December 1974, the United States' ESSA-8 environmental satellite recorded a large cloud mass centred over the Arafura Sea about northeast of Darwin. This disturbance was tracked by the Darwin Weather Bureau's regional director Ray Wilkie, and by senior meteorologist Geoff Crane. On 21 December 1974, the ESSA-8 satellite showed evidence of a newly formed circular centre near latitude 8° south and longitude 135° east. Crane - the meteorological duty officer at the time - issued the initial tropical cyclone alert describing the storm as a tropical low that could develop into a tropical cyclone.