Largest cloud - soliton

Soliton clouds are rare, solitary forms that maintain their shape while moving at a constant velocity. The longest regular occurrence of this is known as the Morning Glory, which forms in the Gulf of Carpentaria, Australia. This backward-rolling cloud formation may be 1,000 km (620 miles) long, 1 km (3,280 ft) high and can travel at up to 60 km/h. (37 mph). The Morning Glory regularly attracts gliders, who catch the updraft on the leading edge of the cloud.