Timely. Make sure you understand it!
> “Water temps reach a seasonal high during the summer, causing a layering process to occur. The end result is an upper warmer layer and a cooler lower layer — separated by a quickly changing narrow band known as the thermocline.
> “You’ll actually be able to see the thermocline as a consistent narrow band on a quality graph. If it’s still there you could still expect to find quite a few fish clinging to deeper summer patterns. If not, it’s time to make some adjustments.
> “The turnover is a thorough mixing of the upper and lower layers of water in a system that had been separated by a thermocline — usually coinciding with the first hard frost of fall. Some years the change is so gradual that it becomes difficult to pin down. When the surface temp drops into the lower 60s and upper 50s, you can figure you’re in the turnover zone.
> “The quick cool-off of the turnover will shut fish down until they’ve had time to adjust. Even lakes that don’t experience a thermocline still go through a period of cooling off with tough conditions.
> “Lakes that experience the turnover first are more shallow and windswept compared to the deeper and more protected.
> “In the middle of a turnover you can avoid the negative effects by spending your time on a deeper lake. The shallower lakes may be a good choice after the cooling process has taken place everywhere because fish will have had more time to adjust.
> “The move to shallow water will depend on how much good shallow-water cover is available (shallow weed-choked bays, rocky bars/reefs, as well as larger weed flats). The food [baitfish] that has been hiding out in shallow cover is now getting pushed out into the open where it becomes extremely vulnerable.”
Read Rick’s full write-up here on Walleye Central.