SAN DIEGO -- Thick fog along the San Diego County coastline Monday could make for a tough morning commute.
A National Weather Service dense fog advisory for the coastal areas is set to remain in effect until 9 a.m. Forecasters said travel could be affected along portions of Interstates 5, 15 and 805, and state Route 163.
"The marine layer and weak onshore flow will bring areas of dense fog near the mesas and other higher coastal terrain in San Diego County and mostly along and inland of Interstate 5 in Orange County through 8 a.m.," according to the weather service. "Visibilities are expected to improve between 8 and 9 a.m. as the fog clears toward the coast."
Forecasters said visibility could drop to less than a quarter-mile at times. The NWS advised motorists to use caution in dense fog, slow down and use low-beam headlights.