LAS VEGAS, NV - JULY 07: Lightning strikes during a thunderstorm as lights from an airplane taking off from McCarran International Airport streak at lower right on July 7, 2015 in Las Vegas, Nevada. The monsoon storm dropped heavy rain and hail in parts of the valley causing street flooding and power outages. (Photo by Ethan Miller/Getty Images)

A massive region from around 29 Palms north to around the home of Lincoln County High School in Panaca, Nev., and from well east of Kingman to Barstow is under a flash flood watch declared by the National Weather Service. It continues until 5 a.m. Monday.

Flash flood warnings, where flooding is presently occurring, are in effect now for areas around 29 Palms and the Morongo Valley and also for the Kingston Range Wilderness near Dumont Dunes. Those continue through later today.

 Locally, a 50 percent chance of rain and thunderstorms is forecast for this afternoon, escalating to a 50 percent chance of severe thunderstorms this evening, and escalating again to a 60 percent chance of severe thunderstorms on Saturday.

Modeling indicates declining chances but continued severity of thunderstorms Saturday and Sunday.