February 1, 2020. GroundFrog Day Celebration in Downtown Snohomish. The Annual Frognostication, “Snohomish Slew” predicts the coming of Spring at this uniquely west coast adaptation of Ground Hog day folklore of Punxsutawney Phil. Slew vs. Phil for the best prediction. Kids Games, Crafts, Music, Mascots, Pictures with Snohomish Slew, Entertainment for the whole family. EVENT IS FREE.