I witnessed an interesting event last month. I was holding at a destination which had forecast occasional light snow showers. This had turned into unforecast heavy snow.
The guy holding 1000 ft below me announced that he was down to minimum diversion fuel and was advised by ATC that the runway was being ploughed and "should be open soon". He decided to stay in the hold.
About 10 minutes later ATC announced that the runway was open but then gave a braking action of 23/12/14 with no improvement for 2 hours!
I was very grateful for the extra fuel that I had loaded and set off happily to my alternate. The chap beneath me was committed to making an approach. I hope he walked away from it. The airport was closed shortly afterwards.
Aviation is constantly full of surprises.