Western U.S. seared by heat as eastern U.S. deluged by storms

(CNN) -- Mother Nature is showing her extremes across the country.

While dangerously hot temperatures broil the Southwest, parts of the Northeast grapple with flooding from torrential storms.

Temperatures across much of the West will soar 10-to-20 degrees above average on Tuesday, the National Weather Service said. Forecasters issued excessive heat warnings for large swaths of California, Nevada and Arizona through the Fourth of July.

"Many of the same locations that broke records recently could shatter records again on Tuesday," the weather service said.

That's dreadful news for much of California, Nevada and Arizona, states that have all seen temperatures top 120 degrees in the past few days.

With the threat of heat stroke or heat exhaustion striking within minutes, hundreds of Las Vegas residents have sought relief in a Salvation Army cooling shelter.

"Not only do they get (from) the cooling station the benefit of the water that we put out, but they can also take showers, if they need to, in here for free," Andre Ingram of the Salvation Army said. He said anyone who comes in can get as much ice-cold water as they need, when "normally they walk around just looking for it."

The extreme heat is hindering efforts to stop Arizona's Yarnell Hill wildfire, which has scorched more than 8,400 acres -- about 13 square miles of land.

The fire killed 19 members of an elite firefighting squad Sunday when fierce, erratic winds whipped the fire in different directions. Parched land from Arizona's drought is also fueling the fire.

East Coast deluged by rain

Much of Arizona would love to get more rain. But residents on the East Coast are seeing too much of a good thing.

Showers and storms will stretch from Florida to New England through Thursday, the National Weather Service said.

That's on top of the rainfall that quickly flooded parts of New Jersey on Monday and stranded motorists in Paramus.

"I didn't think that was going to happen, but it was up to my knee when I got out of my car," Caroline McCourt told CNN affiliate WABC.

Drivers in Durham, North Carolina, also had to push their cars out of floodwater.

And the flooding could get worse -- cities from Georgia to New England could see 2 to 3 more inches of rain in the next few days.

CNN's Dan Simon and Ivan Cabrera contributed to this report.