Tule Fog

Oct 12, 2005
Little Elm Texas
Any of you guys ever had a chance to see winter Tule fog? I used to live in Central California prior to moving away from this non supercell state and the only weather I really liked was the central valey Tule fog. I could patrol a field when working on the night shift and you can see it develop in trails rising from the moist ground around your feet. Then on the best days it would rapidly fill lower level areas then roll in reaching even greater heights. It is the thickest fog I have ever seen often bringing visibility down to just a few feet in front of you. Once it was so thick that I missed my home street because it was impossible to read the street signs, incredible stuff and the only weather I miss in California.
It's amazing and yes on the worst days of it it will fill up the entire California valley :!: As evaporative cooling takes place and the fog begins to develop it has nowhere to be blown off by winds since mountains surround the lower valley on all sides. If you ever find yourself in the state during the months from November to February check this stuff out it's the thickest fog you will ever get to see.
Tule fog. Winter pea soup fog-apalooza in the Central Valley of California. I just rolled into town day before yesterday from spending a week in Northern California so had to drive through the whole deal from Sacramento (near San Fran) south to the Tejon Pass, as the road ascends into the Angeles Natl Forest north of LA, about 6 hours. I was carrying a large piece of artwork so driving to CA made more sense this year than the normally easy 1 1/2 hr flight from Phoenix.

Tule fog can be incredibly thick, causing big driving hazards too. It is a radiation fog variety that has Californians staring wishfully, hoping for any glimpse of veiled-out sunlight, for weeks at a time in December. There are even road signs along California highways that test for impaired fog visibility. They say - 100 ft, 50ft, 10ft, etc.

Quite often, especially the late night through early morning hours, tule fog can cause zero vis on the roadways. On a couple occasions where a patch takes drivers off guard, I have had to roll my window down and listen, using sound for driving enhancement, as headlights are often useless. Tule fog easily obscures even close objects. I remember one time the tule fog hid an entire locomotive, which I only knew was coming from the sound.

My perma-cure for winter sunlight deprivation when I lived there? Take up skiing. The more you ski, the more you get out of the fog layer and spend time on the sunny Sierra Nevada slopes within an hour's travel time, and have access to some of the best snow in the world (although it is wetter snow than the kind in Colorado). That's how I dealt with winter tule fog. In addition, driving trips or flights in the afternoons are better. The other way I dealt with it is I moved to the Arizona desert! :)
I have never experienced Tule fog but have heard of it and all the big chain wrecks it caused in California. This was a concern to me when I retired from NCEP and was moving to Oregon just before Christmas 1999. While I had a moving company move the furniture, etc., there were a few items that I couldn't or didn't want them to move so I was driving my RAV4 with a U-Haul trailer in tow. To avoid winter weather and extreme grades I took the deep south route. That meant I had to go the whole length of Tule country in California, south to north. I got lucky, though. It was warm and very hazy but no fog, and I got to my destination without incident.