There really isn't a tire to help with wet conditions. The contact patch on a bike tire is too small for any treads to make any difference. Wet weather handling is more of a handling skill then anything a tire can help you with, as bicycles are NOT cars.
The Kenda Kross Plus is smooth in the center with knobs on the edge. It works decent on both smooth and sandy surfaces, but at a compromise, which any "all purpose" widgets are.