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Storms flood parts of Vegas, Navajo land, Calif. desert communities, Utah town

Residents in four Southwest states were drying out Wednesday after thunderstorms flooded Las Vegas streets, stranded Navajo families in northern Arizona, left two mobile home communities in Southern California deep in water and caused a dike to fail in a Utah town. 

In the Las Vegas area, the Tuesday storms delayed flights, snarled traffic and prompted helicopter rescues of stranded motorists. A golf course worker was reported missing and a search for the man resumed Wednesday, NBC affiliate KSNV-TV reported.

Television news video showed school buses inching along roads after school east of downtown Las Vegas, and muddy water up to the lower sills of windows of stucco homes in other neighborhoods.

In southeast Las Vegas, authorities urged the residents of about 45 homes damaged by flooding to leave in case electrical fires are sparked. 

Dozens of cars were swamped by water up to their headlights in a parking lot outside the Thomas & Mack sports arena at the University of Nevada, Las Vegas.

Firefighters responded to more than 20 calls about people in stalled cars .

John Locher / Las Vegas Review-Journal via AP

University of Nevada students Ryan Klorman, left, and Markus Adams relax on inflatable pool toys in floodwater in a parking lot at UNLV in Las Vegas on Tuesday

A Las Vegas police helicopter was dispatched during the height of the storm to pluck several people from swamped vehicles on roadways.

More than 1.75 inches of rain were reported in downtown Las Vegas. The rainfall amounts put the region on pace to exceed the 4.5 inches of rain it normally gets in a year.

Tuesday was also the wettest September day on record in Las Vegas, weather.com meteorologist Nick Wiltgen reported

Thunderstorms leave Las Vegas under water as flash floods strand motorists and lightning strikes delay flights at McCarran International Airport. NBCNews.com's Dara Brown reports.

Calif. mobile home parks hit hard
In California's Coachella Valley, a thunderstorm on Tuesday dropped more than the average annual rainfall there in one night alone, settling for six to eight hours over Mecca and Thermal, desert towns 150 miles southeast of Los Angeles.

In Thermal, the downpour flooded the Desert Mobile Home Park better known as Duroville, a community of mostly migrant workers with about 1,500 people, including 900 children, that has long been the subject of legal fights as Riverside County officials attempt to relocate residents. 

More than a foot of water stood in the southern end of the park, knocking out power to about 800 people for much of the day. 

"None of us had ever been through anything like this," said Tom Flynn, the court-appointed receiver for Duroville. "That much water in a dilapidated mobile home park was something to see." 

The lack of power knocked out electric motors on both of the park's wells, leaving no fresh water until one was revived and county workers brought several tons of bottled water. 

The park has no paved streets or drainage, and health officials were concerned about overflow from two ponds that serve as the community's sewers. 

Between 60 and 80 people had evacuated from the park and were spending the night at a high school. "The poorest of the poor were hit the hardest," Flynn said. 

St. Anthony's Mobile Home Park in Mecca also was affected, but fared better than Duroville. Video clips showed residents wading through knee-high water and cars creeping through flooded residential streets. 

The storm dropped 5.51 inches of rain near Mecca and 3.23 inches of rain near Thermal, meteorologist Mark Moede said. The average annual rainfall in arid Thermal is just shy of 3 inches, he said. 

"That's an amazing amount of rain," Moede said. "It's unusual anywhere to get a storm that sits stationary for five to eight hours."

Arizona and Utah flooding
On the Navajo Nation reservation in northeastern Arizona, many of Tuba City's roads were underwater and residents stuck in their homes. State Route 264, one of two main arteries in and out of town, was closed after a bridge washed out about a mile outside of the community, Tuba City Chapter Manager Benjamin Davis said.

Flooding was reported in some homes but no residents were displaced, Davis said.

Meanwhile, a dike that broke during heavy morning rain flooded nearly four square blocks in the southern Utah city of Santa Clara. More than 30 homes and business were evacuated after the break.

City Manager Edward Dickie said the dike along a retention pond sent a deluge of water into downtown.

Scott G. Winterton / The Deseret News via AP

This neighborhood was among the areas flooded in Santa Clara, Utah on Tuesday.

"It didn't just breach. It broke. It's gone," he said, adding that the flooding quickly receded as water drained into rivers and creeks.

Such a wide area across the Southwest was hit, Wiltgen told NBCNews.com, because moist, unstable air interacted with a disturbance in the upper atmosphere. 

"The disturbance helped to trigger the scattered thunderstorms that popped up across a broad swath of the Southwest," he said, "and these storms translated that very moist air into flooding downpours."

The Associated Press contributed to this report.

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