your right Ken, tho have seen nights with good seeing but really windy - or cloudy - you have to laugh on those occasions eh
traditionally it is widely followed that when the isobars are widely spaced enough in an isobaric chart - most commonly with sloooow moving huge high pressure systems - that is the time - but the trailing western edge can be dodgy with an approaching front ect. influencing ahead of itself - but on rare occasions here it can be good with huge spaced slooooow lows too -
i agree about seeing for the last couple of years with these antarctic lows reaching up in to southern oz all thru summer - they used to get held down by the dominant, ants pace, highs - but the little puny wishy washy, tightly spaced, highs we have been getting for a few yeras are taking a belting at the hands of these roaring 40's type lows - they get pushed and bullied along and out of the way before they can get established - i remember a few huge high pressure sytems hanging around for what seemed weeks years ago?