This isn't a question, but it's something I found while doing research for something else. It might be helpful for others. https://mae.ucf.edu/fcrar2018/wp-content/uploads/2018/05/8_FPU-Visibility-Drake-Luckey-Erickson-cr.pdf Ever struggle to come up with an idea of how dense a "Dense Fog" really is? How about a moderate fog, or just a thin fog or a haze? How about how far you might expect to see on an "Very Clear" day? Well, now you know! There's apparently a scientific difference between "Fog" and "Mist." Interestingly, by this definition, Steven King's Mist was not.