In reply to Bernard's comment "That's a very interesting video in that it doesn't show the usual Foehn gap": For starters, the main ridge producing this is perhaps 15-20 miles away and hidden behind the nearby hills. There was a lot of cloud on the upwind side around Mt Buller, Mt Useful, etc. You can see the occasional roll cloud bits on the lower left of the frames. Often, the pre-frontal NW winds are quite dry and we get a lot of blue wave days with only isolated lennies.
In reply to Noel's comments: "It puzzles me though as it turns into mammatus immediately behind its leading edge. That usually indicates severe turbulence but the wind sock remains nearly dormant. Did you obtain met. details for the day? Uwe Radock did a lot of research re. that system in the fifties and date may be available from Melb. Uni.." I think it is the same mechanism as mammatus - a moist layer above a dry layer with mechanical action (in this case wave flow) forcing the cloud down into the dry air. You can see the protrusions going back up, indicating stable air that is producing the wave. Re the slack windsock - I think this depends a bit on the location of the wave itself. Some days, we have howling winds locally with wave and others very light on the ground. Normally, with a dry Northerly, it arrives with a bang as the flow breaks up the inversion that had disconnected upper and lower winds. On windy nights, we often lie in bed at night listening to the rotors thrashing towards us and have, on 1-2 occasions, heard a deep, almost subliminal rumbling of the wave. This is something I've described for the Canterbury Plains wave cloud in NZ. Re the met: yes, I have this detail if interested. The 00Z YMML trace shows a lot higher winds than forecast and some intense drops and jumps in dew point (>25 degC over 200m) indicating several moist and dry layers. Re the system: Uwe Radok (who I knew when I was a sprog in the MU Met Dept in the early 70's) worked on the Warburton Wave off Mt Donna Buang whereas this is coming off Mt Wellington NE of Licola. I used to fly the Warburton Wave in my Ximango out of Lilydale and have two 25,000' climbs in it from there. These days, I live at Lake Glenmaggie. Cheers John
_______________________________________________ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
