LOS ANGELES (CBSLA.com) — A storm will strike the Southland Thursday, possibly bringing about flash flooding and torrents of mud and debris.

According to the National Weather Service, the rain will begin Thursday morning across San Luis Obispo and Santa Barbara counties.

It will then spread to Ventura and Los Angeles counties in the afternoon and overnight, exiting L.A. County by Friday morning.

The storm is expected to be the biggest for the rainy season so far, which runs from October to May.

Rainfall totals will range between a half-inch and 1.5 inches in coastal and valley areas, and between 1 and 3 inches in the foothills.

A flash flood watch will be in effect through Friday morning in the burn areas of Los Angeles County.

Potentially damaging winds will also threaten the region.

A high wind warning, projecting winds blowing at 58 miles per hour, will be in force until 10 a.m. Friday in the San Gabriel Mountains and the Antelope Valley.

The city of Glendora has been placed on a yellow alert ahead of the storm. The yellow alert puts into effect rain-related parking restrictions due to the possibility of flooding. No evacuation orders are in effect, however.

With snow levels forecast to drop to 4,000 feet, Glendora Ridge Road in the San Gabriel Mountains has been closed from Glendora Mountain Road to Mt. Baldy Road beginning at 4 p.m. Thursday to motorized vehicles. Bicyclists and pedestrians will be allowed. The road is expected to reopen by noon Monday.

All city- and county-funded winter homeless shelters in the San Gabriel Valley have been notified to stay open around the clock in response to the storm.

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