Oklahoma City residents are advised to prepare for a shift in weather patterns with forecasters from the National Weather Service in Norman anticipating potentially hazardous conditions over the coming days; today’s sunny skies with highs near 93 degrees will shift as thunderstorms enter the outlook starting Thursday. With humidity already at a sticky 97 percent before sunrise, the city expects heat index values as high as 97 by the afternoon, the mercury just beginning its climb toward the end of the week, according to the National Weather Service.