Scientific Fishing: Barometric Pressure

[Josh Smith]

Hello all,

For as long as I can remember I've fished. I started before I was three at Little Flat Rock creek when we lived in Greensburg IN.

Now, my dad has studied a lot of fishing techniques, especially for bass. He left the books and magazines laying around and I'd read them, and continue to this day. I apply the knowledge to see what works and what doesn't. I've combined this knowledge with other scientific principles I've studied.

This deals with barometric pressure and the effects it has on fish, specifically bass but applicable to other species also.

For those of you who don't know, barometric pressure refers to air pressure. A sudden rise or drop is what makes your ears pop and also what makes a house's windows explode when a tornado comes through.

Barometric pressure affects fish thus: High pressure makes them 'dizzy' and lethargic- they have no desire to feed. Conversely, low pressure or fluctuating pressure wakes them up. They tend to bite like crazy as a low pressure storm front is approaching.

One question is how to keep a constant watch on barometric pressure. A simple barometer is useful. Before you go out and spend big bucks on one though try this: Take an empty tin can and stretch a balloon or non-lubricated condom across the top. Fasten a straightened paper clip to the middle of the rubber with Elmer's glue or hot glue (hot glue sometimes messes with condoms though). This is your needle, your pointer. After this is accomplished take a ball of Play-Doh and stick an unsharpened pencil in it. Let the Play-Doh harden and position the pencil so the needle is pointing to it. Mark the position.

If you'd like, look up the current barometric pressure on a site such as weather.yahoo.com. This will give you a starting point if you want to be even more accurate.

Keep your barometer in a place where there's not much temperature variation or sunlight and watch that sucker. Once that needle starts to drop in a big way, stop whatever you're doing and get out to your favorite fishing hole ASAP. If it dips radically, watch for tornadoes on your way to your favorite fishing hole .

(This is an older article I wrote five years ago, modified properly for this forum. Figure it might be a discussion generator).

Regards,

Josh

[ClarkIR]

You posted some useful information but I am nitpicking... The earth will never experience enough natural pressure change for glass to break... Glass is usually broken from wind speed and projectiles... Also several factors other than pressure change need to be in place before you should worry about severe weather.

[Josh Smith]

You posted some useful information but I am nitpicking... The earth will never experience enough natural pressure change for glass to break... Glass is usually broken from wind speed and projectiles... Also several factors other than pressure change need to be in place before you should worry about severe weather.

Hello,

Yeah, it's simplistic. It was originally "part 1" in what was going to be a multi-part series that got more in depth and complex, eventually combining all the factors I know of that effect fishing.

This one pertains mainly to freshwater, summer fishing.

Where did I say something about glass breaking?

Regards,

Josh

[Moveon]

You posted some useful information but I am nitpicking... The earth will never experience enough natural pressure change for glass to break... Glass is usually broken from wind speed and projectiles... Also several factors other than pressure change need to be in place before you should worry about severe weather.

Evern been in a Tornado's path. Lot's of glass gets broken during a tornado. And a Tornado is created by differential air pressures. Lower air pressure inside the tornado creates intense wind speeds in excess of 200 mph. Swirling winds inside a tornado can easily smash a window out or even blow the doors of buildings. I've been inside a building when a tornado blew right over the building and all the glass doors blew out of the building at once. Pretty scary time in my life.

But as far as fishing and BP I think that many other factors of the storm front have an effect on the fishing. Increased winds and more surface action on the top of the water decreases the amount of light entering the depths and increases the dissolved oxygen contect. The winds also redistrubute the phytoplanknton on the lake's surface. Decreasing light caused by the clouds cause the algae and zooplankton to rise up in the water column. I would hate to be a fish in the water when a lighting bolt hit the water's surface. If I were a fish I'd go deep to get away from any potential lighting strikes. And I would not come back to the surface until I got really hungry and the storm had passed.

[ClarkIR]

I have never, nor hope to be in a tornado's path, but you are confirming what I am saying that wind and projectiles cause damage and not a drop barometric pressure. The eyes of hurricanes have the lowest BP measured on the planet (BP of Hurricane Katrina was 902 millibars). Eyes are also considered the calmest part. No damage is done in the eye.

Nobody knows for sure why or how tornadoes form... but it isnt because of differences in Barometric Pressure. Low pressure allows for warm air to rise and create convection(step one of supercells that can lead to tornadoes) but, the biggest reason they believe is the difference in temperature of the downdraft as it wraps around the mesocyclone...but they are still known to occur without said temperature differentials.

I will say you are spot on(or at least read the same things I have) on Fishings impact with BP... ive been told fish go deep after a thunderstorm because of being spooked, but the biggest bass I have ever caught (4.5lbs) was literally minutes after a thunderstorm had just passed.