HA I've sailed under two of roll clouds, one with lightning near Port Macquarie and the other on Bass Straight. Neither was immediately associated with strong wind. The Port M one was at night and the cloud was only visible when lit up by lightning. It was raining like mad at the time but the passing of the cloud was not associated with any obvious change in conditions below and the wind remained 25 kts and apart from the rain and a freaked out crew, the conditions running with the wind on the quarter were fine.
The other cloud on Bass Straight was horizon to horizon near Green Point. The Hobart fleet was going downhill under spinnakers with a pleasant 12 knot wind over the decks. It was not until the cloud had passed well over us, some two hours later, that the wind changed from NE to SE and it did that quite slowly and then increased in strength to over 40 knots on the nose. Interestingly, some of the crew got seasick as soon as they saw the extent and height of the cloud even though the sea state didn't change for some time. I've seen roll clouds associated with southerly buster fronts on the coast of NSW and these normally have a really abrupt wind change under them and move very fast up the coast. Not much in common between these types of roll clouds and the MG other than shape. D _______________________________________________ Aus-soaring mailing list [email protected] To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
