A slow moving upper level low and monsoon moisture fueled thunderstorms over the Mojave Desert.  Many storms produced flash flooding and severe weather.

Lightning in CLARK, NEVADA
From 13-SEP-11 01:00:00 to 13-SEP-11 01:30:00 (PST-8)
Location: BOULDER JCT
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Lightning struck numerous trees and at least one home.

Thunderstorm Wind in CLARK, NEVADA
From 13-SEP-11 02:10:00 to 13-SEP-11 02:10:00 (PST-8)
Location: LAS VEGAS
Magnitude: 43.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Thunderstorm winds knocked down power lines in downtown Las Vegas.

Flash Flood in CLARK, NEVADA
From 13-SEP-11 07:00:00 to 13-SEP-11 09:15:00 (PST-8)
Location: WANN
Flood cause: Heavy Rain
Property damage: 250.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Flash flooding affected much of the Las Vegas Valley. Water flowed through the intersections of numerous streets, with one described as a rushing river. Rocks, debris and mud covered some roads. Four feet of water and mud flooded the first floor of a home after a sound wall in the back yard failed. One swift water rescue was performed.

Lightning in CLARK, NEVADA
From 13-SEP-11 07:28:00 to 13-SEP-11 07:28:00 (PST-8)
Location: BRACKEN
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Lightning struck a home, damaging the roof.

Flash Flood in CLARK, NEVADA
From 14-SEP-11 13:10:00 to 14-SEP-11 13:30:00 (PST-8)
Location: BRACKEN
Flood cause: Heavy Rain
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Two drivers had to be rescued from the southbound off ramp of the 215 Beltway at Flamingo Road when they got trapped in standing water 3-4 feet deep.

Hail in CLARK, NEVADA
From 16-SEP-11 13:05:00 to 16-SEP-11 13:15:00 (PST-8)
Location: BOULDER CITY
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Flash Flood in CLARK, NEVADA
From 16-SEP-11 13:29:00 to 16-SEP-11 14:01:00 (PST-8)
Location: BOULDER CITY
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Numerous streets were flooded in Boulder City.

Hail in LINCOLN, NEVADA
From 16-SEP-11 13:20:00 to 16-SEP-11 13:30:00 (PST-8)
Location: PIOCHE
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Flash Flood in LINCOLN, NEVADA
From 16-SEP-11 17:35:00 to 16-SEP-11 19:00:00 (PST-8)
Location: URSINE
Flood cause: Heavy Rain
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Water and debris flowed across Highway 322.

Flash Flood in LINCOLN, NEVADA
From 16-SEP-11 19:55:00 to 16-SEP-11 20:30:00 (PST-8)
Location: PANACA
Flood cause: Heavy Rain
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Water and debris flowed across Highway 93.

Flash Flood in LINCOLN, NEVADA
From 16-SEP-11 19:30:00 to 16-SEP-11 21:00:00 (PST-8)
Location: PANACA ARPT
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Water and mud estimated at 75 feet wide flowed through Cathedral Gorge State Park, chasing approximately 20 campers out of their tents.