This weekend wind/thermocline/productivity

[carpedium]

Based on this link:

http://www.glerl.noaa.gov/res/glcfs/glc ... pe=N&hr=-1

It looks like there has been a breeze from the NW over the last few days. Its pretty clear that this breeze has been causeing upwellings of cold water along the canadian side, and pushing all of this warm water toward the american side. Furthermore, judging by the tightly packed bars around 15M on cross section "B" it looks like there is a thermocline finally set up for this weekend.

My questions, if you'd be so kind to provide your input:

- This wind condition (From the NW) looks to be pushing the thermocline lower and moving it around, but not really disturbing its overall presence. This suggests that fishing should be good as far as that goes on the american side this weekend, correct?

- Around 43.45 Lat there are some major shifts in the location of this thermocline, and as you get further out, it seems to greatly stabilize. Is this evidence that fishing will be better down 60-120 over say... 300-400?

In using this data as a tool, am I missing or misinterpreting anything? I'd like to start understanding what is going on based the tools available and what I have learned so far instead of just blindly "following the pack".

Thanks,

Matt

[bluewater]

I have always done well with a northerly wind, last year I did 14 kings one day on a slight nw wind out in 120-150 fow the last week of July about 60-80 feet down.

[Paul Czarnecki]

You're reading it all wrong. What you are calling "thermocline" is, in fact, surface temp and is vastly different from thermocline. Thermocline is "SUB surface" temp stratification that occurs in the summer as the water warms up. To make a long story short it happens a little like this....

Cold water is denser than warm water. As the water warms in the summer the cold water sinks deeper (because of its density). The "thermocline" is established when the lake has finished "the transition period" and the warm water is sitting atop the cold water. Typically, fishermen refer to the "thermocline" as where the cold water and warm water meet----although, technically, that is wrong.

With regard to the effect of the west winds on the lake you are on the right track. Wind acts on the warm water first because it is the easiest to move. The NW winds we had this week pushed the warm water away from the Canadian shore and onto the American side. The warm water that was on the Canadian shore is now gone and was replaced by the cold water---an upwelling. On the American side we have just the opposite results. The cold water moving to Canada has allowed the warmer water to move in and our "down temps" have warmed considerably. In short, right now you are going to have to go out further, or fish deeper, to find cold water.

Hope that makes things a little clearer as you defintiely don't want me to give you the longer version....LOL.

Good luck!

[GAMBLER]

The thermalcline has officially set up. The intake temp where I work went from 47 degrees to 66 degrees in 24 hours. I find where the thermalcline meets the bottom and start there trolling north until I find fish. I will be out Saturday out of Sandy. Call me on the radio if you want info. My boat name is escape. Good luck.

[carpedium]

You're reading it all wrong. What you are calling "thermocline" is, in fact, surface temp and is vastly different from thermocline. Thermocline is "SUB surface" temp stratification that occurs in the summer as the water warms up. To make a long story short it happens a little like this....

Cold water is denser than warm water. As the water warms in the summer the cold water sinks deeper (because of its density). The "thermocline" is established when the lake has finished "the transition period" and the warm water is sitting atop the cold water. Typically, fishermen refer to the "thermocline" as where the cold water and warm water meet----although, technically, that is wrong.

With regard to the effect of the west winds on the lake you are on the right track. Wind acts on the warm water first because it is the easiest to move. The NW winds we had this week pushed the warm water away from the Canadian shore and onto the American side. The warm water that was on the Canadian shore is now gone and was replaced by the cold water---an upwelling. On the American side we have just the opposite results. The cold water moving to Canada has allowed the warmer water to move in and our "down temps" have warmed considerably. In short, right now you are going to have to go out further, or fish deeper, to find cold water.

Hope that makes things a little clearer as you defintiely don't want me to give you the longer version....LOL.

Good luck!

Paul,

I'd love to take you up on the "long version" sometime! I'm a geek like that.

Thanks for the info. I think you misunderstood though. I was not referring only to surface temp, but cross-sectional subsurface temp as given for lake O. Graphic "B" in the link above. It shows you isobars of the temperatures vertically as if you were to look at a cross sectional "cut" of the lake.

[carpedium]

The thermalcline has officially set up. The intake temp where I work went from 47 degrees to 66 degrees in 24 hours. I find where the thermalcline meets the bottom and start there trolling north until I find fish. I will be out Saturday out of Sandy. Call me on the radio if you want info. My boat name is escape. Good luck.

Gambler, I'll do that. thanks

[Paul Czarnecki]

You're reading it all wrong. What you are calling "thermocline" is, in fact, surface temp and is vastly different from thermocline. Thermocline is "SUB surface" temp stratification that occurs in the summer as the water warms up. To make a long story short it happens a little like this....

Cold water is denser than warm water. As the water warms in the summer the cold water sinks deeper (because of its density). The "thermocline" is established when the lake has finished "the transition period" and the warm water is sitting atop the cold water. Typically, fishermen refer to the "thermocline" as where the cold water and warm water meet----although, technically, that is wrong.

With regard to the effect of the west winds on the lake you are on the right track. Wind acts on the warm water first because it is the easiest to move. The NW winds we had this week pushed the warm water away from the Canadian shore and onto the American side. The warm water that was on the Canadian shore is now gone and was replaced by the cold water---an upwelling. On the American side we have just the opposite results. The cold water moving to Canada has allowed the warmer water to move in and our "down temps" have warmed considerably. In short, right now you are going to have to go out further, or fish deeper, to find cold water.

Hope that makes things a little clearer as you defintiely don't want me to give you the longer version....LOL.

Good luck!

Paul,

I'd love to take you up on the "long version" sometime! I'm a geek like that.

Thanks for the info. I think you misunderstood though. I was not referring only to surface temp, but cross-sectional subsurface temp as given for lake O. Graphic "B" in the link above. It shows you isobars of the temperatures vertically as if you were to look at a cross sectional "cut" of the lake.

The "long version" requires a few "Adult beverages" at the Black North. However, I do have an on-the-water class coming up on Sunday July 17th where will be covering all that stuff. How's that for a shameless plug??

I realized after I wrote all that that you were probably referring to graphic B but the Lat Lon lines you referred to threw me off. Like I said, you're on the right track. The most important thing to remember with Lake Ontario is cold water is heavier than warm water. Everything else is usually a function of the wind acting on the water.

[tcon]

Great info... thank you Paul and Matt for asking the question.

Tom

[TyeeTanic]

Good info Paul.

So do you think us guys without a temperature probe can kind of rely on the government

cross section maps. For instance cross section A of Lake Ontario is Toronto, which I'm close

enough to. If I read this, it seems there is a vertical thermocline about 2 miles from shore and

then it goes flat at around 4 miles in around the 60 - 70 ft mark.

That is if we are looking at 55 'C to 60'C temperature band.

It seems like the ministry publishes this data twice a day, and it would be easy enough to take a quick

look on the phone internet before heading out.

[carpedium]

You're reading it all wrong. What you are calling "thermocline" is, in fact, surface temp and is vastly different from thermocline. Thermocline is "SUB surface" temp stratification that occurs in the summer as the water warms up. To make a long story short it happens a little like this....

Cold water is denser than warm water. As the water warms in the summer the cold water sinks deeper (because of its density). The "thermocline" is established when the lake has finished "the transition period" and the warm water is sitting atop the cold water. Typically, fishermen refer to the "thermocline" as where the cold water and warm water meet----although, technically, that is wrong.

With regard to the effect of the west winds on the lake you are on the right track. Wind acts on the warm water first because it is the easiest to move. The NW winds we had this week pushed the warm water away from the Canadian shore and onto the American side. The warm water that was on the Canadian shore is now gone and was replaced by the cold water---an upwelling. On the American side we have just the opposite results. The cold water moving to Canada has allowed the warmer water to move in and our "down temps" have warmed considerably. In short, right now you are going to have to go out further, or fish deeper, to find cold water.

Hope that makes things a little clearer as you defintiely don't want me to give you the longer version....LOL.

Good luck!

Paul,

I'd love to take you up on the "long version" sometime! I'm a geek like that.

Thanks for the info. I think you misunderstood though. I was not referring only to surface temp, but cross-sectional subsurface temp as given for lake O. Graphic "B" in the link above. It shows you isobars of the temperatures vertically as if you were to look at a cross sectional "cut" of the lake.

The "long version" requires a few "Adult beverages" at the Black North. However, I do have an on-the-water class coming up on Sunday July 17th where will be covering all that stuff. How's that for a shameless plug??

I realized after I wrote all that that you were probably referring to graphic B but the Lat Lon lines you referred to threw me off. Like I said, you're on the right track. The most important thing to remember with Lake Ontario is cold water is heavier than warm water. Everything else is usually a function of the wind acting on the water.

Hey, i'm buyin' the drinks! Don't get the wrong impression even though I fish out of sandy........ Guilt by association is not fair. (viewtopic.php?f=52&t=24963&hilit=sandy+creek+shootout&start=15)

I'd seriously consider a class - keep me posted with the schedule. I can't make the 17th 'cause I'll be up fishing Lake George.

Thanks again for the info Paul.

[carpedium]

Good info Paul.

So do you think us guys without a temperature probe can kind of rely on the government

cross section maps. For instance cross section A of Lake Ontario is Toronto, which I'm close

enough to. If I read this, it seems there is a vertical thermocline about 2 miles from shore and

then it goes flat at around 4 miles in around the 60 - 70 ft mark.

That is if we are looking at 55 'C to 60'C temperature band.

It seems like the ministry publishes this data twice a day, and it would be easy enough to take a quick

look on the phone internet before heading out.

I think 60 C is a little too warm. I don't know how warm, but my days in Quebec, NS, and NL taught me a few things! I think it would be reliable for general purposes, but as always YMMV. There really isn't enough resolution bet the farm on it.

[TyeeTanic]

I don't know about you guys - but on the north shore, all the fish were sitting high in the water today (July 1). They were all at 30 ft of water and sometimes less, in almost consistently 130 total water depth. I couldn't believe how high they were, almost didn't use the dipsey's as it wasn't worth while. Well, actually didn't on two lines - put 3 oz weights on instead and put out enough string to make sure they were at the 40 ft depth, and got several hits with these.

2 biggies - I figure 20 to 30 lb fish, broke my connector line and lead (20lb floro). I was a little frustrated ....

[Paul Czarnecki]

They were higher in the water column because the NW wind pushed all the warm water south leaving only cold water on your north shore. Given enough time it will come back and with a south wind it will come back VERY quickly.

[ Post made via BlackBerry ]

[TyeeTanic]

We had a bit of a SW wind andi started spotting fish at the 40 to 50 ft mark sonthings are getting back to normal.

[ Post made via BlackBerry ]

[LongLine]

Those transects are interesting however you really can’t see much for water less than 150 ft deep. Remember the vertical scale is in meters (approx 3 ft)

I’ve found the best use of them is to visualize the general pattern. What I do is click on the times, say -6, -12, -18, -24, -36 etc then click on the “back†arrow on the browser to see what the lake has been doing, then on the forecast for +3, +6, +12 etc. I also do this on the surface temps to visualize where the cold water is going and try to mentally connect the two together.

Another thing to remember, especially in 50 to 160 ft range is that the water temps can be quite different 1 mile away from those lines. (Also note on surface temps map, if you scroll down they show what the bottom temps are doing.)

After all your calculations are done & you think you have it all figured out, just use that as a start point. i.e start shallower then go out past it & adapt to what your screen/probe shows you.

Tom B.

(LongLine)