Severe Weather

Former Hurricane Norbert's Moisture Fueled Flash Flood Threat In Nevada, Arizona, California, Utah

The threat of dangerous flash flooding is ending across the Desert Southwest after moist, tropical air from former Hurricane Norbert -- and the downpours it spawned -- set records.

The National Weather Service issued a flash flood emergency for Moapa, Nevada, and nearby areas Monday afternoon and evening. Major flash flooding was reported in Moapa, which lies along Interstate 15 about 45 miles northeast of Las Vegas. That Interstate highway was partially destroyed in the flood.

(MORE: Floods Swamp Nevada, Arizona; 2 Dead)

Monday was a record-breaking day in Arizona as well. Phoenix's Sky Harbor Airport had recorded 3.29 inches of rain Monday, making it the wettest calendar day on record at that location. Monday morning's weather balloon released at the National Weather Service office in Tucson measured more water vapor than had ever been measured in the air above Tucson since records began in 1951.

(MORE: Latest Radar, Warnings and Live Storm Updates)

Flash flooding also struck several locations across southern California, southern Nevada, and Arizona on Sunday.

(MORE: Floods Drown Cars in California's Inland Empire)

Norbert's moisture, in tandem with remnant moisture from ex-Tropical Storm Dolly and the residual moisture already in place from the North American Monsoon, combined to enhance rainfall potential in the Desert Southwest.

High pressure aloft over the Southern Plains provided the steering wheel for this deep tropical moisture intrusion.

Fortunately, as drier air moves into the region, the flash flood threat is quickly diminishing. Scattered thunderstorms will mainly be confined to southeast Arizona and New Mexico Wednesday.

(FORECASTS: Phoenix | Las Vegas)

The most dangerous thing you can do in a flash flood is drive your vehicle into waters of unknown depth. It only takes two feet of rushing water to carry away your vehicle. If you see flooding ahead, turn around, don't drown.

(SUMMER FLOOD RECAPS: Mt. Baldy, CA Landslide | N. Phoenix Flood)