Correlation Between Tide Change & Wind Changes

[Slider]

Many would know that a change in tide can bring on a wind increase, or change of direction. I have even noticed that fronts or storms can come through with the tide change and land breezes turn to sea breezes. The last couple of mornings has seen light breezes from the SW/S turn more onshore and increase dramatically with the start of the run out.

So for all you meteorologists out there - why is this so?

[Still_Dreamin]

You are a brave person slider. I noted this phenomenon(?spelling) to some other fisho friends and was nearly laughed out of the pub! But I agree winds often change around tide changes

[llourd]

here is a thread with several plausible theories. most seem to agree there is a correlation, question is why and here are several possibilities to think about...

http://www.ybw.com/forums/archive/index.php/t-261318.html

[Noelm]

wonder how many "fronts or storms" come through without a tide change?? I would reckon 10 times as many as do happen to coincide with a tide change, an offshore wind early in the morning is common and nothing to do with the tide, it has to do with temperature differences between land a sea, simple as that.

[Slider]

I once believed that to be the case also Noelm, but I can guarantee that it's not as simple as that.

There has been an awareness that wind changes can occur on tidal changes since the ancient mariners. Long line skippers in the Coral Sea shift their anchorage prior to the tide change to allow for an expected wind increase or change of direction. Other offshore pro fishers have told me the same thing.

Living next to the surf and having had an awareness of this for a long time now, I take note of wind alterations and they very regularly coincide with tidal change and mostly with a morning run out. Not always, but far too often for it to be coincidence.

I'll check the links that Ilourd has put up.

[Noelm]

I also live right on the water, and except for times when the wind blows all night, there is ALWAYS a light offshore wind, right at dawn, regardless of whether it is high tide, low tide or anywhere in between, not that I for minute suggest there isn't some sort of correlation between tides and wind and moon and christ knows what else, but there is always exceptions to the rule.

[Crunchy]

Moon affects tide, moon affects weather, therefore although it this does not imply causation there may well be correlation.

The moon does have an effect on Earth's weather, but apparently no one knows for certain how. The moon causes atmosphere tides, just as the moon causes oceanic tides. It appears that you can expect colder temperatures when the moon is full or new due to this effect. When the moon is full or new, it causes a bulge in the atmosphere, just as it causes a bulge in the Earth's oceans. When the moon is full or new, the Earth, Moon and Sun all line up, and the gravitational forces of the Sun and Moon act together on the Earth. This effect is especially pronounced when the moon is closest to Earth (at perigee). When the moon is at perigee and when the moon is either full or new, a particularly pronounced drop in temperature can be expected.

Read more: http://wiki.answers.com/Q/How_does_the_moon_effect_weather#ixzz21Q0vZBSc

[Slider]

I would expect that the moon is integral to it Crunchy. The most common scenario of a wind change occurring with the tide that I've noticed, is when there is an early to mid morning high which is always associated with either the full or new moon. As soon as the tide starts to run out, the wind either changes strength (increases) or direction.

But according to the long liners and offshore pros I've spoken to, it is almost a daily event and all month round.

[Crunchy]

Yes indeed, the relationship between tides and the wind changes you are experiencing is however not causal, merely correlated. What I dont understand though is how can something made out of cheese have such a big influence on stuff?

[tunaticer]

I'm not convinced that the changes are majority in sync with tidal changes, I would think maybe 30% of the big swings occur with tide changes from my observations.
I have noticed that the bigger changes of wind occur around dawn and dusk with the temp changes.

[Slider]

No, certainly doesn't occur on every wind change, but it does happen and sometimes predictably so. But why does it happen at all?

[snapperbasher]

Slider,

My old man always used to bring this up when out on the water....when we were young and fishing out of a small clark tinny all over moreton bay he would always ensure we were heading home if there was a change in tide especially around that mid morning to lunch time..... I remember asking him why this happened and he said he wasn't 100% sure but believed it was to do with the massive amount of water which changed direction at that time..... I have pondered this many a time since and believe he could be onto something......when you sit back and think how much water is moving in a complete different direction on a change of tide it could well affect the wind....

the fact that it happens to a more noticeable degree on the moons would back this up..... being that there is generally more water movement on the moons???

We all know that seabreezes are caused by temperature...early morning the sea is warmer than the land and the warmer air rises over the ocean and is replaced by the cool air off the land but as the land heats up in the middle of the day it then becomes warmer than the ocean and the reverse happens....theres your seabreeze....

but a change of tide slightly earlier or later than this seems to bring it on.....

something to think about anyways??

[WalrusLike]

Guys have a google of "confirmation bias".

Not saying the moon doesn't affect the weather.... but that if you think it does then you will see all sorts of confirmations... and ignore any discrepancies.

That's just human nature.

[Slider]

I'd go along with that Snapperbasher - when I say that it's moon related, then I'm also including tidal movement which this situation is specifically related to, but obviously controlled by the moon. My belief is that the change in tidal direction creates a pressure release which allows an air mass to fill the void. The larger the high tide size, the greater the release and the more immediate is the response of the air mass. Or something like that.

Perhaps we should ask Livio.

[thelump]

Dont know if this helps or adds to anyones theory but a recent observation. Saturday night just gone did an overnighter in the Cobby. Change of tide(top of high) after 11ish saw the wind pick up very strong. So strong I had to move to more sheltered area. Woke up in the morning (bottom of low) saw light winds. Nearly dead still! Also noticed wind was strong around the Saturday afternoon low to high change. Any help?

[Slider]

Just adds credence to the fact that it does happen Macca.

This topic came up on here a few years back and we were just getting into the topic when an individual who is/was well respected around the rec fishing traps, posted that the tide has nothing whatsoever to do with wind. And that was that - no more posts and none of us became any the wiser. But there is definitely a correlation and those who are aware of it can build this knowledge into their fishing activities. Time runs across Moreton Bay so as to avoid getting hit by wind and tidal change mid bay for instance. So, if you have a 9am high tide and the forecast is for moderate SW to SE, then ensure that you are underway by 7am. If the breeze is 10 knots SW when you leave, then you can be pretty sure it's going to stay that way and not going to turn into 15 - 20 knots of SE mid bay. If you don't have this knowledge and you've downed a bottle of bundy the night before and being casual about departure times, then the days fishing can turn pretty ugly on you.

[Slider]

Tides turning - breeze has swung from NW to NE and kicked a couple of knots.

[Slider]

Actually, the breeze briefly swung to the NE with a couple of small storm cells that turned up just as the tide began to run. Then dead still.

[nigelr]

Would personally agree with Noelm on this; lived within 200m of the high tide mark for the last 33 years and my take would be diffence between the land and sea temperatures.
I'm going to try and take note of your theory though Slider and try and make some observations. I'm thinking maybe could depend on the size of local (saltwater esturine) inland water bodies in contrast to straight land/sea coastal landscapes?

[Slider]

I probably have an assessment advantage in that I hear the breeze change through the sound of the surf. I can sit at my pc, hear a change in the surf noise due to wind direction, look at the clock and correlate with tide times. Probably been paying attention to it for 15 years since a pro mackerel fisherman was astounded that I wasn't aware of the correlation.

[nathank]

its a weird thing that is hard to put some kind of hard facts towards correlating the two together.. tide and wind changes.. I was just talking about this the other night and bang on the low tide (night time) the wind picked up.. Ive seen it happen so many times and always wondered why?

[Slider]

I'm not sure if anyone knows why Nathank - would be great to establish a reason.
I've decided that there might be an easy way to test this. The BOM site has daily half hour observations of wind direction and wind speeds. I'll select a few random days and a few random locations and draw up a chart with wind speeds/direction around tidal changes and post the results. We'll see what happens. I noticed that the wind kicked here yesterday after the morning low, but I doubt that high pressure driven westerly air flows are when these sorts of changes are most likely to occur.

[WalrusLike]

Slider if you truly want to know if your effect is real or if it's a case of confirmation bias you need to do it scientifically.

That means select the days truly randomly ie use a random generator to select the month and the day and do as many as you can.

Do not discard any because they don't fit. Good luck... I hope you see a correlation. But of course if it was science it would need to be statistically significant to 95%. And that's just to get a gernsey. After that its cross checked and further confirmed or refuted.

[WalrusLike]

There are a lot of other factors to doing it correctly..... For instance you might need to break it into summer, winter, spring etc. and work randomly keeping that one variable constant. Or maybe assume that is only when a high is over the center of Oz.... And only examine those days randomly.

As you can see it is not a trivial undertaking if you want to do it right.... And I have only just scratched the surface here....

[Slider]

And I just couldn't be bothered going to those lengths unfortunately WalrusLike. It's not that important - just an interest thing. But let's say I have time on 7 days over a period of a fortnight, then we might get an indication. Or we just ask Livio - last time I tried that though, the Ch 7 website crashed my pc.

[TheRealAndy]

Tide started running back in yesterday and the wind came in. Ask a sailor, they know. I was sitting on the dock yesterday, little wind. We needed the wind cause we had to win a race to take out the series. Sure as the sun rises in the east, soon as the tide turned the wind came in.

[captain rednut]

hi Lindsay i have always noticed this and i remember my father telling me when i was a kid that the wind can quiet often pick up on the turn of the tide. its very interesting and i believe its defiantly associated.
cheers Jim

[Slider]

G'day Jim - thought you'd be on to it.

At Agnes the other week with Chook an crew - didn't notice any changes there - think it stayed at 35 knots through every tide.

[marto78]

Slider if you truly want to know if your effect is real or if it's a case of confirmation bias you need to do it scientifically.

That means select the days truly randomly ie use a random generator to select the month and the day and do as many as you can.

Do not discard any because they don't fit. Good luck... I hope you see a correlation. But of course if it was science it would need to be statistically significant to 95%. And that's just to get a gernsey. After that its cross checked and further confirmed or refuted.

Or you could do a phone poll asking 300 random people if the tide changes affect the wind. Than you can take your results to the government and charge them $250,000 for your results and we can stop people going fishing when there is a change of tide just in case there is also a strong wind change which might make it to dangerous for the average snapper fisherman. ;D
(All tongue in cheek of course)

[marto78]

On a serious note but, in regards to Moreton Bay if the wind is howling (excess 20knts) we always plan our trip home to coincide the tides and winds and have noticed that after the tide changes to the same direction as the wind that the wind does seem to back off a bit.

For example we did a 3 day camping trip at Moreton last year on the Queens Birthday weekend (I think) and it was blowing 30knts SE all weekend and we planned our trip back home to Nudgee to coincide with the out going tide, although I haven't checked the observations it did feel like the wind had dropped out quite a bit by the time we were half way across the bay.

I don't know if the wind and tide are related or not but I do know that if you have wind against tide in the bay (especially strong winds) you can expext the in the middle of the bay to have a lot of sizeable pressure waves. But if the wind and tide are heading the same way the wind does not seem to have as punch and the bay is a lot more manageable.