* WHAT...Visibility one quarter mile or less in dense fog.
* WHERE...San Francisco, Coastal North Bay Including Point Reyes National Seashore, San Francisco Peninsula Coast, Northern Monterey Bay, Southern Monterey Bay, and Northern Salinas Valley/Hollister Valley and Carmel Valley.
* WHEN...Until 9 AM PDT this morning.
* IMPACTS...Low visibility could make driving conditions hazardous.