After a gray and rainy Sunday,  metro Atlanta residents should prepare for a sunny, but chilly start to the work week, according to Channel 2 Action News meteorologist Brad Nitz.  "Skies will clear overnight as our temperatures drop to near freezing in metro Atlanta," by Monday morning, Nitz said.  Expect a low of about 42 and a high of 53, Nitz said.  As colder and drier air blows into north Georgia this evening, residents can expect see a few snow flurries in the mountains before midnight.  Sunshine returns on Monday, with a morning low of 33, and an afternoon high that should reach 57 -- the average high temperature this time of year, Nitz notes.