The Associated Press

SAN FRANCISCO — The storm that pummeled much of California for three days began moving east Thursday after causing at least six deaths, forcing wildfire victims threatened by floods to flee their homes and plunging nearly 300,000 utility customers into darkness.

The winter storm is forecast to unleash heavy rain, snow and wind in Colorado and “will be slamming the East Coast by Sunday,” National Weather Service forecaster Steve Anderson said. “From Maine to Florida.”

Anderson said most of California should be dry and sunny by Friday.

The three-day drenching put a dent in California’s drought, dumping as much as 10 inches of rain in parts of Southern California, and between 3 and 6 inches in Los Angeles. Government and university researchers who maintain the U.S. Drought Monitor map classify most of the state as abnormally dry or in moderate drought. Only about 6 percent is in severe or extreme drought, compared to nearly a quarter of the state last September.

Rain and snow fell from one end of the state to the other, canceling flights, knocking down power lines and causing flooding.

In Malibu, a boulder hit a 57-year-old woman while she was hiking Thursday. She was in critical condition.

In Riverside County, firefighters rescued 12 homeless people stranded on an island in the Santa Ana River bottom, while 25 other transients were evacuated from the river banks.