Tuning in to Channel 3's morning newscast, we're never quite sure who we're going to see. Perhaps we're imagining it, but it seems that at least once a week, anchor Mary Williams (or, as she pronounces it, "Wee-yums") is MIA. Likewise, KMTV seems to play roulette when it comes to filling the morning weather chair. Friday, for example, we were (pleasantly) surprised to find our favorite pair o'