Barometric Pressure

[PGottshall]

Someone posted a link in the old forum to a site which had a history of barometric pressure by zip code.

Does anyone have this link?

Thanks,
Paul

[Jerry Blake]

Hey Paul:

This is probably what you're looking for - http://weather.noaa.gov/

Here's four more that will give you a real good idea of what to expect over the next 24-hours:

Current Surface Conditions

Morning Forecast

Midday Forecast

Evening Forecast

[Barnacle Bill]

Glad to see this. I thought maybe I was the only one that watches barometric pressure. Not that it matters whether it is falling, rising, or whatever, I still go fishing. I've been keeping a log of every fishing trip for several years now. One of the things I record is the starting/stopping pressures of each trip.

[ncnat]

I have too, not long enough top tell anything yet. You?

[Moose1am]

Would you do me a big favor and also record the amount of cloud cover and the wind directions and air temp and water temps. The clarity of the water is also important for such fishing logs.

You see I have this theory that the amount of light reaching and penetrating the water is the key to where the fish are loated and also the main reason for the winds and waves and the amount of sunlight also effects the water's temp and were and how deep the plant life grows in the lake.

You see without sunlight there were be no changing barrometric air pressures.

The sun drives the energy cycles and all life on earth except for those deep ocean vent holes which run on chemical energy not sunlight energy.

Measuring the BP helps predict what the weather will be like and that is a good thing. But just remember it the sunlight and the amount of cloud cover, the winds and waves that determine what the fish will be doing.

The actually air pressure may not really effect the fish as much as Bill Dance and some of the other non scientist fishermen say.

Water is so much more dense that air that the water pressure where the fish live is not changed by the changing air pressure above the water's surface. You see a fish that changes depth by two feet is affected by a lot greater change in water pressure than any change in the air pressure above. The Greatest changes in air pressure that have been recorded all though history are those that occur when a hurricane comes though and area. Even then the changes in air pressure are only a few inches of mercury. The air pressure may go from 32" of mercury down to 27" of mercury. Now that 5" of mercury air pressure change is nothing compared the the pressure change that a fish experiences when it dives from the shallow water down into 32ft of water. There the fish would experience a water pressure change of 29" or one Atmosphere or 760mm of mercury. 5" compared to 29" . And most fronts only change the air pressure by less then an inch or two of mercury. So 2" compared to 29" is a very insignificant changes in pressure. And the key is not the changes in the air pressure above the fish but the changes in the water pressure at the depth that the fish are using. A 2" change in air pressure may not really change the water pressure that much at 10ft deep or even at 2ft deep. Changing air pressure is caused by heavier and denser air being in the area and that air pressure combines with the water above the fish to press on the fish. Fish do have lateral lines and swim bladders that can be effected by RADICAL changes in water pressure but I seriouly doubt very much that a change in water pressure of 2" of mercury effect the fish that much. What effects the fish the most is the water temp and the amount of dissolved oxygen and other chemicals that are dissolved in the water and the amount of sunlight that penetrates though the water to the fish's eyes. You see fish don't have eyelids and they can't close their eyes shut like we mamals can. They don't even have pupils that can constrict to shut out the sunlight like we do. They have to find shade or go deeper in the water where the sunlight is filtered out by particles floating in the water. Some clear lakes have fish swimming at 30ft depths routinely as long as there is enought dissolved oxygen down in those depths. Dale Hollow lake would be a prime example.

Also we all know that fish come shallow in the very early morning hours and when the sun sets. It's not the changing air pressure that make the fish come out of deep water to feed in the shallow water. Think about this. Does the air pressure alwasy drop or rise with the setting and rising of the sun? Of course not! But the amount of light that penetrates into the water is DIRECTLY controlled by the rising and setting of the sun eac day.

Use the changes in BP to predict what all the other factors are going do do. Ie in most cases if you see the pressure dropping you know that a front may be coming though the area. This may mean increased winds and changes in wind direction and increasing clouds in the sky. The increase in clouds will help block out the sunlight and fool the fish into thinking its sunset and the fish will come into shallow water to feed. On cloudy days the fish don't have to wear sunglass. LOL They can feed all day long in the shallows and not have to worry about getting sunburned. Also it's harder for hawks and eagles to see down in the water from above and the fish feel safer when the water is darker. The fish have to be more careful on bright sunny days and they become more visible to overhead predators who can see deeper into the water on bright sunny days. So the fish stay out in deep water on bright sunny days not only to avoid the sunlight but to avoid the potential overhead predators. Birds such as double crested cormorants also do better at catching fish underwater when they can see the fish below the water's surface. The bright sunlight helps the birds see the fish in the water and zero in on their prey.

Use changing BP as an INDICATOR but don't think that the actual changes are really influcing the fish. Remember that the cannary in the coal mine does not cause the miners deaths when there is poisonous gas in the mine. The canarry does not casue the poisonous gas but only warns of them when it dies from breathing the noxious fumes. Since the cannary is so much smaller than the human miners it sucombs faster to the bad air and warns the miners that it's time to leave the mine before they too die.

BP changes is like the cannary. It warns of things to come but is not necessarily the cause of those changes.

--------------

Steps down from the soap box now!

Glad to see this. I thought maybe I was the only one that watches barometric pressure. Not that it matters whether it is falling, rising, or whatever, I still go fishing. I've been keeping a log of every fishing trip for several years now. One of the things I record is the starting/stopping pressures of each trip.

[jcass]

One simple way to record water clarity is to make your own "secchi disc". It is a white disc that is lowered into the water until it dissapears from sight, then raised until it becomes visible. The depth is recorded at that level.
You can make your own simple one and use it at different lakes and times to compare data. There is an article on it at:
http://www.mlswa.org/secchi.htm

[Barnacle Bill]

I have been keeping track of Phase of moon, air temp, water temp, barometric pressure starting/stopping, fish caught, water condition, winds and clould condition. Oh yea, where and when too.

[Moose1am]

Good man! That is an excellent project.

I was thinking about getting a water proof log book some day to record that stuff and my waypoints. I sometimes accidently delete all my tracks, waypoints and routes from my GPS unit and I found it's a good thing to also write them down somewhere on paper. Computer stuff can get deleted too easily.

I have been keeping track of Phase of moon, air temp, water temp, barometric pressure starting/stopping, fish caught, water condition, winds and clould condition. Oh yea, where and when too.

[Moose1am]

One simple way to record water clarity is to make your own "secchi disc". It is a white disc that is lowered into the water until it dissapears from sight, then raised until it becomes visible. The depth is recorded at that level.
You can make your own simple one and use it at different lakes and times to compare data. There is an article on it at:
http://www.mlswa.org/secchi.htm

[TAE73]

Would it matter if you used your polorized glasses? Since they help you cut the glare and allows you to see in the water better. This could change the final reading of the disc.