The reference in Wiki includes: "The cloud can also be described as a solitary wave or a soliton, which is a wave that has a single crest and moves without changing speed or shape." - But they illustrate it with a picture of 3 parallel morning glory clouds.
The newspaper article says: ' . . . "Morning Glory" clouds, which can stretch up to 1km-long . . ". Wiki says up to 1000 km long (which is what I have read before, and the picture certainly seems to show much longer than 1km).
In view of the speed of the wave, which the pilot has to stay in front of or risk getting into the really turbulent top/middle/back of the roll cloud, getting into the latter certainly sounds dangerous to me. As to whether more so than rotor, I suppose it depends on the rotor. Some UK ones are quite rough. Some USA ones have broken gliders, I believe, but somebody over there might be better informed. Seeing the size and vigour of the morning glory, it is not something I would like to be in the wrong part of.
Chris N.
(edit to clarify, and to remove comment about aerobatics)
Last edited by chrisN; 30th September 2009 at 00:30.