The National Weather Service in Oklahoma City has issued a flood advisory until 10:30 AM CST this morning for parts of central Oklahoma, including Cleveland, McClain and Oklahoma counties, due to heavy rainfall and thunderstorms sweeping the area. As reported by the NWS, “Flooding caused by excessive rainfall is expected” and has already begun in some areas with minor flooding in low-lying and poor drainage areas, with ponding of water becoming imminent or currently happening.