Thick enough to cut with a knife

So for the past few days or so we have been getting some dense eery fog. Saturday and today the morning was nice and clear, but the fog just spread and overtook everything. Sunday the fog was still there from Saturday. It must be an Idaho thing. I remember fog every so often in GR, but fog is guaranteed here during the winter. Although it makes driving here pretty difficult it leaves hoarfrost that is beautiful. Occasionally it get so thick we cant see past our front porch.