Saturday, April 09, 2005

AUSTRALIAS - Morning Glory

"THE REMOTE SETTLEMENT of Burketown, in Australia’s northern Queensland, is not the sort of place you’d expect people to travel thousands of miles to visit. With a population of just 178, Burketown sits in one of Australia’s most remote shires. But every September and October, a small group of individuals journey from all corners of the country for the appearance of a remarkable and dramatic cloud called the Morning Glory. Clouds don’t usually have names, nor are they normally linked to a particular location, but then the Morning Glory is no normal cloud. Looking like a huge white roll of meringue, it stretches up to 600 miles (about the length of Britain) and sweeps over Burketown at speeds of up to 35mph. The visitors who come to marvel at this beautiful and awe-inspiring meteorological phenomenon are an intrepid group of glider pilots, for whom the cloud promises the most unique and thrilling flying conditions of anywhere in the world. Each year they come to this sleepy town in the hope of ‘soaring’ the Morning Glory, an exhilarating gliding adventure that can only be described as cloud-surfing."
Credit: http://www.cloudappreciationsociety.org/3content/glory/glory1.html

Flying along the face of a Glory.



Spencer Gulf - This photograph depicts a unique example of a roll cloud over Spencer Gulf, South Australia. The picture was taken at 1.15 pm, 27 November 1977 by the co-pilot of an Airlines of South Australia aircraft while on approach to land. He estimated the length of the cloud to be 5 kilometres. The camera was pointing west and a further faint roll is just visible
to the west of the main one. The ship near the centre of the picture was the Danny F, which was 230 metres long. This puts the thickness of the roll and the height of its base around that figure. A north-easterly airstream had resulted in humid sultry conditions over most of South Australia. with isolated thunderstorms a day or so before the event. An interaction of this air mass with a cooler south-easterly anti-cyclonic flow towards the South Australian coast undoubtedly contributed to the formation of this well-defined roll.

From: Solitary waves & low-altitude wind shear in Australia,
D.R.Christie & K.J.Muirhead,
Aviation Safety Digest 123/1985.

Port Hedland Roll cloud - At sunset on the north-west shelf off Port Hedland. The cloud continued over the horizon. Photograph courtesy of Miss J. Statham and Dr M. W. Skinner.

Aviation Safety Digest, Special Issue 1986