California drenched as new atmospheric river brings thunderstorms and winds

Several flood advisories issued as governor declares states of emergency in 21 counties, with more snow set for higher areas

There is no end in sight for California's brutally wet winter as yet another atmospheric river storm collided with the state on Friday, bringing torrential downpours, thunderstorms and wind. The National Weather Service issued a slew of flash flood warnings and watches for already inundated areas from the San Francisco Bay, to the central coast and the Sacramento and San Joaquin valleys, with more stormy weather expected through the weekend.

Snow-covered mountain towns in the Sierra Nevada foothills braced for another round of heavy precipitation. So much snow has fallen across the ranges that residents are still struggling to dig out days after earlier storms; now, warmer rains are threatening more damage to towns and buildings by adding more weight to snow-heavy roofs that could cause them to crumple.