SAN FRANCISCO (KRON) -- A dense fog advisory is impacting portions of the Bay Area during the Wednesday morning commute. The advisory, issued by the National Weather Service, affects San Francisco, the San Francisco Bay shoreline, the North Bay and the East Bay and Santa Clara valleys. Tule fog is causing visibility of a quarter mile or less, weather officials said. The poor visibility could cause hazardous driving conditions during the morning commute. Officials advise drivers to turn on low-beam headlights when approaching fog, drive slowly and keep distance from other vehicles, use extra caution on bridges and in valleys and be ready for sudden changes in visibility. Hawaii-bound flight from San Jose diverted to SFO due to disruptive passenger The dense fog advisory expires at 11 a.m.