SAN DIEGO (AP) - California's cold snap has only just begun.

Friday morning's temperatures dipped into the 20s and 30s in many parts of the state and much lower in the mountains and the freezing temperatures are expected to last through the weekend.

In Sonoma County, homeless shelters started handing out extra warm clothes to protect people from below-freezing overnight temperatures.

In the south, forecasters warn that a low pressure trough sinking over San Diego County and parts of Orange County could keep nightly temperatures below the freezing point in coastal areas, the low deserts and inland valleys, threatening orange and avocado orchards and other sensitive plants

The California Highway Patrol shut the Grapevine segment of Interstate 5 on Thursday afternoon, forcing hundreds of truckers to spend the cold night in their rigs. The vital north-south artery north of Los Angeles re-opened today.

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