High humidity levels, summer heat and long days will combine to produce conditions favorable for drenching thunderstorms leading to additional flash flooding in the coming days in the eastern, central and southwestern United States, AccuWeather meteorologists warn. There has been a swarm of flash flooding incidents in several parts of the U.S. in recent weeks. Anytime there is a great amount of moisture in the atmosphere and a front, storm, or jet stream fluctuation occur s, tremendous rainfall