If you have previously recommended this thread, you should see a tick / check mark on the recommend button. Click the tick to undo the recommendation (the tick may appear to change to a cross as you do this.) If you added a comment with your recommendation, you will need to delete that from your facebook wall separately.
I've just realised that I was only looking at the warning section and that we have got more snow forecast today. Hopefully, it's not going to be as much as we've already had and that's why it's not got a weather warning on it <fingers crossed>.