Forecasters say millions of people in the central United States could see powerful storms Monday including long-track tornadoes, hurricane-force winds and baseball-sized hail. The National Weather Service forecast that much of Oklahoma and parts of Kansas are at the greatest risk of severe weather.  The National Weather Service’s Storm Prediction Center says in all, nearly 10 million people live in areas that could be affected. Some of those areas in Oklahoma are still recovering from tornadoes. Schools and colleges across the state have shut down early and canceled late afternoon and evening classes and activities. The forecast follows heavy rainfall in Houston, where floodwaters began to recede Monday. Read moreMillions of people across Oklahoma, southern Kansas at risk of tornadoes and severe thunderstorms