BAKERSFIELD, Calif. (KGET) — The National Weather Service issued a dense fog advisory for parts of Kern County in effect until Saturday morning.

National Weather Service forecasters in Hanford issued the advisory for Friday night and expires at 11 a.m. on Saturday, Dec. 17.

The advisory warns of a “high transportation risk” along multiple highways in the San Joaquin Valley including highways 99, 43 and 41. In Kern County, the highest risk stretches along Highway 99, portions of highways 58 and 178, I-5 and south into the Grapevine.

Drivers are advised to slow down, use low beam headlights and keep plenty of distance from vehicles in front of them. Visibilities could be as low as 200 feet in some areas, officials said.

Visibilities of less than a quarter mile in Visalia were reported Friday night, the weather service tweeted. CHP reported visibilities were down to 200 feet along I-5 through the Buttonwillow area.