So glad you posted this! I'm doing a 15K on Sunday in cold, rainy, crap weather! Hoping to run half, walk half. Totally scared! But I'm hoping that it will make me more prepared for my half marathon on May 2 (the Flying Pig). I tend to get caught up in the energy of the other runners and go too fast (which leads to side cramps), so I'm going to start out walking so that all the fast people can be far ahead of me.
Good luck