Monsoonal moisture swept across Nevada and Southern California on Thursday, triggering downpours that flooded the Las Vegas Strip and thundershowers that doused streets in Los Angeles, Orange and Riverside counties.
The body of a man--a possible drowning victim--was found in a Las Vegas wash Thursday afternoon. Police said a woman died in a Las Vegas auto accident that may have been caused by the heavy rain.
July rainfall is a relative rarity in the Southwest, with measurable precipitation falling only about once every seven years in downtown Los Angeles. Parts of Las Vegas got about 3 inches Thursday, more than two-thirds the normal total for an entire year.
Forecasters said winds circulating around an upper-level high-pressure system over the Central Plains have been drawing warm, damp air from Mexico into the Southwest, setting off thunderstorms in Southern California, Nevada, Arizona, New Mexico and southern Colorado.
This sort of occasional monsoonal condition, energized by heat, occurs here most commonly in July, August and September.
Guy Pearson, a meteorologist with WeatherData Inc., which provides forecasts for The Times, said there could be a few lingering showers today before the moist air dissipates to the east.
Torrential rains began pounding Las Vegas shortly before noon Thursday. Runoff quickly flooded Interstate 15 and nearby surface streets, bringing traffic to a halt. Several motorists had to be rescued from their stranded cars.
Streams of muddy water swept away several mobile homes on the southern side of the city, as residents scrambled to safety.
Although portions of Caesars Palace were closed by the rising flood waters, gambling continued unabated and there were no reports of serious damage.
"The Strip is a lake, up over the curbs, into our fountains," said Phil Cooper, a spokesman for Caesars.
A leaking roof caused a ceiling to collapse at a Las Vegas supermarket, but there were no reports of injuries.
Runoff on taxiways and limited visibility shut down flights in and out of McCarran International Airport for 45 minutes. At least two jetliners headed for Las Vegas had to be diverted to Los Angeles.
Motorists slowed to a crawl as thunderstorms pelted mountain highways in San Bernardino and Riverside counties.
By nightfall Thursday, rainfall totals in Southern California included 2.46 inches in Big Bear City, 1.04 inches in Keenwild, 0.80 of an inch in Hemet, 0.48 in Imperial Beach, 0.32 in Temecula, 0.14 in Fallbrook, 0.06 in Costa Mesa, 0.03 in Monrovia, 0.02 in Pasadena and 0.01 in Long Beach and Culver City. No measurable rain fell in downtown Los Angeles.
The record downtown rainfall total for July is a scant 0.24 of an inch, set in 1887. The last time it rained downtown in July was in 1996, when 0.02 of an inch fell.
The Associated Press contributed to this story.