Crazy barometer next few days

I normally go fishing around my work schedule and not the weather forecast, but check this barometer out for the next few days.

Monday looks good to me

The bigger the fish you are after the smaller the impact. In general I'm a firm believer barometric pressure is over rated as a predictor when it comes to catch rates. I subscribe to John Hope's theories on the matter. Big fish do the same thing day in and day out. They are going to be there doing their thing, only is question is whether you'll be there?

It can have a massive effect on the movement of the fish. They typically move more when the pressure is lower. I've got years worth of logs that show, on average, more activity on days with a low pressure reading than days with high ones. Better catch rates too. And the basic science behind it is sound.

I'm not saying folks should let the barometer tell them when to fish and when not to - but it can really make a difference.

I've looked at tens of thousands of data points from all over the country from the past several decades. In general I've been able to show virtually zero statistically verifiable change in catch rates, in all but the most extreme cases. In my opinion individual logs of a few hundred or a few thousand fish is way too small a sample to draw statistically significant conclusions about something as complex as fish behavior. The number of variables involved demands a huge sample set. If you've got more than a few thousand data points that shows something different, send me a PM, I'd love to see it!

Not to start a statistical or scientific debate here but under what control did you gather your massive data set under? Not that I have any other statistical experience other than what I learned in college but if memory serves correctly a larger data set does not always give you a more accurate analysis. For example if the data was not collected in a controlled manner (or as controlled as possible) then the information gathered would be useless. For example does your data set take into account what I call the fair weather fisherman? Thru personal experience, I have seen far more boats on the water fishing when the sky is clear and the weather is warm (typical high pressure situation) vs cloudy dark sky with some rain mixed in (typical low pressure situation). Now considering that if the number of fish reported are the same would that not suggest a higher catch rate on low pressure days? I am not saying this is the case I am just saying loosely gathering data all over the country and comparing that to the barometric pressure will not yield an accurate statistical model. Unless the large data source you speak of was part of a massive study for fishing and was performed correctly I think I would trust timwins31 data more. Odds are his data was collected using more of a scientific method, one persons way of fishing vs the barometer. Having said all of that, In my "limited" personal experience it is my opinion the smaller fish are more affected by change in barometric pressure than the big girls.

I wouldn't worry about the pressure. Fish still have to eat..

Big Kev, it's a great question. Unfortunately, there is a very long answer. If you are really interested, I'd be happy to chat with you about it over the phone. Shoot me a PM and we can chat sometime. Statistics is a big part of what I do for a living. In a nut shell though, I compared tens of thousands of catch data points to location specific hourly weather. There are ways you can use the data to control for things like "fair weather fishing." For Instance, there are lots of times, when you have beautiful weather with dropping pressure and vice versa. You are correct though, it was not a controlled scientific experiment. To my knowledge, that has never been done on a large scale. Where ever possible I adjusted for various forms of potential bias. In this case, large data most definitely helps. There are far too many potential variables at play to use a few hundred data points. Also, change in pressure isn't even a particularly great of a predictor for weather. Note on his graph on Sunday you've got dropping pressure and sunny skies. On the following Sunday you've got climbing pressure and thunderstorms forecasted. The opposite of what most folks think of.

John Hope studied big fish with transmitters in them for 15 years. He noted barometric changes seemed to impact smaller fish (although he never studied very many) Larger fish however, seemed entirely undaunted. They did the same things they always do, every day, regardless of pressure.