Thanks Michael for pointing it out as I forgot to check myself. The storm on the Alice Springs radar was nicely moving ahead of the advancing bow echo segment. I had suggested in a sort of forecast that a boundary was going to set up in the region and this is what this storm was attempting to do - follow an east west oriented boundary. Nice to see the cell trying veer slightly left of the mean flow. Not sure whether the storms were surface based - Michael may wish to show a sounding of this event from Alice Springs. However, models were indicating NE winds feeding the storms and meeting southerly oriented flow along a boundary near Alice Springs.