Video: People's houses are floating in Arizona! The United States faced what few expected!

continued to sweep the United States , with more than 14 million people in the South and Southwest under a flood watch, according to the National Weather Service. During what the NWS called continuing "multi-day rain," flash flooding struck overnight, leaving drivers stranded on roads turned into rivers, online videos of the chaotic traffic stoppages showed. Meanwhile, more than 20 rescuers continued to search the national park after an Arizona woman went missing as flash flooding made parts of the park unsafe for visitors. Flooded roads have crept into areas and as the weekend's rain in the Northeast lingers into Monday. Here's what you need to know about the floods hitting parts of the country