This question was sent in by Jay Daniels. "From time to time, we've had very dense fog at the ground levels. Yet, when we go to cross over the mountains, say at afton mountain, the skies are absolutely clear, with fog only on the ground. What causes this?"
Click on the video for the answer.
If you have a weather question send it in.
Click here to send your question: www.whsv.com/weather/misc/169671956.html