Storm at sundown - leads to sharp frost at midnight.

Monday evening saw a very loud thunderstorm roll up from out of the Kangaroo Valley. I was sufficiently alarmed to turn off the Computer and TV.
Eventually the storm passed over, and I heard on the radio, about an hour later, that it had dumped a bucket of rain on Wollongong, and was heading into the southern suburbs of Sydney. It was a fast moving storm. We are exactly 100 Km from Sydney (directly - according to the Bureau's Radar Map - which has a neat distance measuring device on it).
Just after Midnight, Lena needed to go out for a wee. She was keen, at first, then stopped on the front verandah, and looked back in some alarm. I went out myself, and realised that the temperature had plummeted. I could hear the frost on the ground crunching under my feet. That is a sound I remember from my days in Canberra.

I grabbed the camera, and obtained this image of a sharp frost on the much cover over the soil - taken with flash, of course. You can see the pinkish red shoots of the herbaceous Peonies (hybrid varieties) at the top of the image.
I imagine there will be a very white frost in the morning. I know Lena will be reluctant to go out then. As we got some rain before the sky cleared off, we will probably have a bit of permafrost, with ice crystals lifting up small stones and the very friable soil here. Brrrrr! Chilly, but pretty.