Hurricane Hilary is strengthening to Category 4 heading toward Southern California

Hurricane Hilary strengthened to a Category 4 hurricane Thursday evening, the National Weather Service said.

The hurricane is expected to hit southern California with heavy rainfall as early as this weekend, after making its way to Mexico’s Baja California Peninsula.

Forecasters said the storm is expected to produce 3 to 6 inches of rain, with a maximum of 10 inches, over parts of Baja California through Sunday night, with the possibility of flash flooding.

There will likely be “damaging wind gusts,” especially at higher elevations in the area, and swell along the coast, Greg Postel, a hurricane and storm specialist with the Weather Channel, said. told CBS News.

The storm, which is not expected to be one Hurricane by the time it reaches California, it will hit the southwestern U.S. with heavy rainfall Friday through early next week, “peaking on Sunday and Monday,” according to the National Hurricane Center.

“It’s rare — even almost unprecedented in modern history — to have a tropical system like this pass through Southern California,” Postel told CBS News.

The last time Southern California was hit by a tropical storm was in 1939, before storms got names, CBS News senior weather and climate producer David Parkinson said. Several storms that were hurricanes or tropical storms have since hit the state, but by then they had weakened to subtropical systems, Parkinson noted.

The storm’s projected path showed it could make landfall anywhere from the Baja California Peninsula to as far north as Santa Barbara, California. One model showed the heaviest rain to hit the Palm Springs area after the storm made landfall.