Just checked the manual gauge. Just 18mm....
Then checked the AWS - had a big fat spider sitting on top of the bucket with an elaborate web. Not sure whether it was his body or his web that tricked the gauge into tipping more.
Oh well, just shy of 20mm (which is a good result anyway). Thinking another mm or two likely tomorrow so should get the 20mm I had hoped for. We've had about 100mm since Christmas so been a productive period (though not as good at Mt Hotham which has had about 300mm
). Grass is nice and green.