Every year many sellers wait until spring and summer to list their home. I speak with sellers who have vacant homes however they want to wait until March or after to list their home for sale. The Zillow link below challenges that thinking and suggest now, the winter, January can be a very good time to list.
In Knox County single family inventory is down 51% since August of 2014 and 45% since June of 2015. That benefits sellers who if they list now will face little or no competition from other sellers.
The low inventory being experienced right now is not seasonal. It has been steadily declining over the past year.