This weatherman briefly appeared in the episode, Mother Nature, but had no significant role other than being chased by an angry mob.
He replaced the recently fired Stormy Raynes, but much like his predecessor, he predicted the weather wrong once and was quickly chased out of Dimmsdale by an angry mob. He is never seen again. (He nervously predicted sunny, but it was snowing)
His name is sort of a play on former KABC-TV weather meteorologist, Johnny Mountain.