Merced will see dense fog this week. What you need to know
The tule fog that Merced County saw earlier in the month is coming back.
The Merced County Office of Emergency Services on Tuesday issued a dense-fog advisory for Thursday through Saturday, with the worst conditions expected in the mornings.
The MCOES provided these tips for driving in the fog:
- Turn on your low-beam headlights, so others can see you
- Leave early to allow extra travel time
- Keep several car lengths of distance between you and the vehicle ahead
- Slow down and stay alert for sudden drops in visibility.
While the mornings are expected to be cool and foggy, high temperatures are expected to be in the low 70s through Saturday, according to the National Weather Service.
There’s a 20% chance of rain on Sunday after 10 p.m., the NWS says.
Why is it so foggy in Northern California and the Central Valley?
These low-lying clouds typically form in the valley during the colder months when winds are light and the soil is moist.
Tule fog becomes especially dense when moist marine air, calm winds and clear skies come together.
“The Central Valley is fertile ground for the formation of tule fog, a persistent radiation fog, in late autumn and winter,” NASA says.
Jan Null is a former National Weather Service forecaster in Northern California and current professor of meteorology at San Jose State University. “The perfect recipe for radiation fog ... is for there to be low-level moisture, clear skies and light winds,” Null said.
