What does an Aloha , Oregonian know??
Us Californians are always right!!
So don't be a silly baby and pout in the corner or I'll have to Spank you and give you a time-out young man!
Tule fog (pronounced too-lee) is a very thick fog that collects in parts of California during the rainy season of the late fall and winter. It is a type of radiation fog, caused by the combination of increased humidity due to the rain and rapid cooling due to the longer nights. Tule fog makes for very low visibility and is the cause of many accidents every year.
Tule fog gathers in the Central Valley, from Bakersfield in the south to Chico in the north, and sometimes as far west as San Francisco. Tule fog is created because warm air rises. Cold mountain air descends into the valley during the night and becomes trapped due to low air drainage throughout the Central Valley. The cooler temperatures and reduced sunlight of the winter months make tule fog very slow to burn off, and it can persist for days. The air above the tule fog is warmer, drier, and lighter, further serving to trap the heavy, humid fog within the valley.
Visibility in tule fog ranges from a high of 600 feet (183 meters) to under a foot (30.5 cm). Traffic in zero visibility tule fog has been the cause of fatal accidents, usually due to multiple vehicle pile-ups. Such disasters are often exacerbated by accompanying weather conditions including freezing drizzle and black ice, which makes the road slippery but is invisible to drivers.