LOS ANGELES (KABC) -- Tropical Storm Kay veered out into the Pacific just short of the U.S. border Friday, while dumping rain throughout Southern California.
The eye of Kay came ashore as a hurricane near Mexico's Bahia Asuncion in Baja California Sur state Thursday afternoon, but it quickly weakened into a tropical storm after moving back out over open water.
Late Friday afternoon, it had maximum sustained winds of 40 mph and was becoming less organized, with forecasters predicting it would diminish to a remnant low overnight.
Kay was centered about 130 miles south-southwest of San Diego and was moving west-northwest at 12 mph.
The storm was expected to start a more marked turn to the west that would take it farther out into the Pacific.
The bulk of the rain, which will at times be heavy, is now expected to arrive Friday night and continue through early Saturday morning. Mountain communities and other areas with burn scars should be prepared for significant flash flooding.
Scattered showers and thunderstorms are expected to stick around Saturday.
While the rain is a welcome sight to the parched region, it could also prove to be troublesome for some beach communities. South-facing beaches are expected to see big waves for surfers, with 4-8 foot hurricane-pulse swells.
Long Beach city crews on Thursday night started working to erect sand berms at the end of Ocean Boulevard on the peninsula. Residents closest to the shore also started placing sand bags around their homes to keep the water from getting too close.
But surfers and beachgoers are advised to be cautious, as beaches in the Orange County area may also see some thunder showers.
Similar precautions were being taken in Orange County burn areas, including Laguna Niguel which was damaged by the Coastal Fire earlier this year.
As part of the recovery phase, the city has already created fences, catch basins and inspected runoff areas as a precaution. Fire crews have dug diversion ditches to make sure rain water flows smoothly down the burnt hillside into the canyon.
The rain will bring relief to Southern California after a prolonged, record-setting heat wave that has lasted more than a week. The rain will drop temperatures in the region down to the 80s and 90s. It is likely to bring 1-2 inches of rain to mountain communities starting Friday night, leading to a good possibility of flash flooding.
Desert areas are also vulnerable, expecting about an inch of rain that could wash out some roads.
The Associated Press contributed to this report.