the density of water is highest around 39 degrees, what that means is that when the water is colder than 39 degrees it will be on the top. as the water warms past 39 degrees, the colder water will now be on the bottom of the lake. the fish get highly scattered up and down the water column at that time of 39 degrees
Sometimes when it happens, you can see the change in water clarity. In fact, I put the boat on Saturday in Wolfeboro for the first time this year. It seemed that winni might have been flipping this weekend as well. The water appeare very murky down through the water when normally it is crystal clear. Spun out by Clay and Black Points and it was the same.