Eureka, CA – A Dense Fog Advisory remains in effect for California’s northwestern coast through 9 a.m. PST Wednesday, as the National Weather Service (NWS) in Eureka warns of low visibility caused by a thick marine layer settling over the region.
Dense Fog Creates Hazardous Morning Commute
Early morning travelers across Humboldt and Del Norte counties are facing dangerously reduced visibility—at times near zero—particularly along Highway 101, coastal stretches, and low-lying areas near the Eel River Valley. The NWS advisory, issued late Tuesday, cautions that the dense fog could create sudden drops in visibility, making travel conditions treacherous for motorists.
“Drivers should slow down, use low-beam headlights, and maintain extra distance from other vehicles,” forecasters said. “Visibility can change rapidly, especially near coastal routes and bridges.”
Areas Most Affected by the Fog
The fog has been most widespread along the Humboldt Bay area, Crescent City, and Trinidad, where thick patches formed overnight due to cool, moist air trapped under a shallow inversion layer. Coastal communities are expected to see some clearing mid-morning as daytime heating helps lift the fog.
Inland valleys may also experience brief periods of reduced visibility before improving by late morning. Temperatures are forecast to remain seasonably cool, ranging from the upper 40s to mid-50s, with calm winds along the shoreline.
When Conditions Will Improve
Forecasters expect the marine layer to gradually dissipate by mid-to-late morning Wednesday as the sun breaks through the coastal clouds. However, the NWS warns that fog could reform overnight later this week, particularly in coastal valleys and low-lying areas, as persistent marine moisture continues to dominate the weather pattern.
“Drivers should remain cautious during early morning and late-night hours through the end of the week,” the agency noted. “Fog can redevelop quickly and reduce visibility again.”
Travel Safety Tips During Foggy Conditions
Motorists in the affected areas are encouraged to take extra precautions to ensure safety during fog advisories:
- Reduce speed and allow extra time for travel.
- Use low-beam headlights or fog lights instead of high beams.
- Avoid sudden stops or lane changes.
- Stay alert for pedestrians and cyclists, who may be harder to see in dense fog.
These steps can help reduce the risk of accidents, especially along Highway 101, where heavy fog frequently impacts visibility during the early morning hours.
Outlook for the Rest of the Week
After the fog lifts Wednesday morning, partly sunny skies are expected to return to much of the North Coast. Daytime highs will reach the upper 50s, followed by another round of overnight fog later in the week as marine air remains entrenched along the shoreline. Long-range forecasts suggest mild, stable conditions with limited rain chances through the weekend.
Forecasters emphasize continued caution for early commuters, as fog remains one of the leading causes of weather-related accidents in coastal California.
What do you think of these recurring fog conditions along the Northern California coast? Share your experiences in the comments below.
