Southern California welcomed a surge of moisture that forecasters say could be the first in a series of early March storms, including a potential atmospheric river.

Sierra Madre city leaders issued an evacuation warning​ in anticipation of the upcoming weather event. The warning will be in effect until 6 a.m.

A Pacific storm system moved into Southern California on Wednesday, bringing heavy rain, a chance of thunderstorms and even a "remote risk of tornadoes," the National Weather Service said. Residents in Southern California's burn areas are preparing for possible debris and mud flows however,