How quick can this change? I was fishing in 14-16 ft yesterday and caught 6 fish that were all on the bottom.  Then the bite just stopped.  As I kept fishing I noticed the fish were no longer on the bottom and were suspended 10-12 ft.  As I kept watching he fish finder I started to see the thermocline on my fish finder and it was from 16 ft up to 13 ft.  I didnt think that transition could happen that fast.

Thermoclines are not a fix stationary element and vary by the hour from current and wind. Think of thermocline as a change in water temperature that varies from 2’ to 6’ thick. The DO levels below a thermocline isn’t a void as several fish species live in the colder water zone.

Tom

It's not terribly uncommon for the thermocline to be at different depths in different areas of the same lake.  There's usually some relation, so you're not likely to find one area with a thermocline sitting at 6 foot and then another area of the same lake with the thermocline sitting at 60 feet.  But it's not unusual for it to change a bit as you move in and out of the wind or current.  And as the wind or current changes, it can adjust the thermocline with it.  Again, you usually won't see massive changes, but changes do occur, and can occur pretty quickly under the right conditions. 

On 7/12/2024 at 4:04 PM, Bankc said:

It's not terribly uncommon for the thermocline to be at different depths in different areas of the same lake.  There's usually some relation, so you're not likely to find one area with a thermocline sitting at 6 foot and then another area of the same lake with the thermocline sitting at 60 feet.  But it's not unusual for it to change a bit as you move in and out of the wind or current.  And as the wind or current changes, it can adjust the thermocline with it.  Again, you usually won't see massive changes, but changes do occur, and can occur pretty quickly under the right conditions. 

Is there anything that drives these changes?  Today same area no thermocline out to 30ft.

21 minutes ago, Huckfinn38 said:

Is there anything that drives these changes?  Today same area no thermocline out to 30ft.

Probably wasn’t a thermocline then. Might have been a zooplankton migration or a mass bug hatch. Would explain the few feet difference you saw a bit later as you fished, as well as the absence today. That said, you can completely lose a thermocline over an entire lake in the course of 24 hrs, but it usually takes significant storm and wind activity (think “Wreck of the Edmund Fitzgerald” stuff - lol).

2 hours ago, Team9nine said:

Probably wasn’t a thermocline then. Might have been a zooplankton migration or a mass bug hatch. Would explain the few feet difference you saw a bit later as you fished, as well as the absence today. That said, you can completely lose a thermocline over an entire lake in the course of 24 hrs, but it usually takes significant storm and wind activity (think “Wreck of the Edmund Fitzgerald” stuff - lol).

Ok we had crazy storms yesterday and through the night so had to be it. Im sure what i was seeing yesterday later in the day was thermocline. I didnt think it could change so fast.

33 minutes ago, Huckfinn38 said:

Ok we had crazy storms yesterday and through the night so had to be it. Im sure what i was seeing yesterday later in the day was thermocline. I didnt think it could change so fast.

That might have been the case then (storms), especially since the thermocline was setting up so shallow. If a thermocline, it should reform fairly quickly if stable and hot weather return.

The thermocline is constantly changing where I fish mostly.  Last week it was around 18 feet.   Yesterday is was at 30 feet.  Today I couldn't find any evidence of a thermocline.   Last week surface temp was 89.9 degrees.  That's the hottest water I've ever seen here.  Yesterday, after a little rain, and a couple cooler days surface temp was 87.  Today, after some overnight rains surface temp was 86.   

FWIW I know very little about a thermocline.  I don't understand what I do know.