How do I catch a Surfing/Flying Pikachu on the Poke walker?

I'm confused about this topic and I dont' know weather its suppose to be watts or steps I know that you need 10,000 steps + to find them and I currently have have 8,000 steps in tottal do I need to get 2,000 steps more or does the 10,000 steps have to be all in one day to catch the Flying/Surfing Pikachus?|||you have to get the 10,000 steps in one day and to be sure you get the fly/sure pikachu you need to when searching for a pokemon hol out as long as you can each time till you see 3 exclamation points like this(!!!) to know it surf/fly pikachu this is what im doing right now and i learned from my friend because i watched him do it|||I believe it is a wifi related event. check Serebii.net, it has more info on this.