Hilary prompts evacuation orders in Lake Mead National Recreation Area

Parts of Death Valley National Park are already flooding as rain from Hilary pounds Southern California.

Water was seen streaming over roadways and the park warned of worsening conditions that could leave people trapped without help: "roads will become impassable and the park will likely lose power, communications and potable water," the park said.

Death Valley is the hottest place in the world and one of the driest places in the United States. Hilary has dumped 0.63 inches of rain on the park, triple its August rainfall of 0.21 inches, since early Sunday morning. Death Valley received double its August rainfall in just two hours Sunday morning.

In an entire year, Death Valley records just 2.09 inches of rain, according to National Weather Service data. Hilary is forecast to bring a staggering 2 to 5 inches of rain, which could cause disastrous flooding.