You know the feeling. It's raining out and the change of air pressure has you moving slow and fighting fatigue. Well, humans aren't alone in feeling this change in equilibrium.
Barometric pressure is defined as the pressure of the atmosphere (you've probably heard the term "atmospheric pressure"). It's clear now, right? Try thinking of it this way. When barometric pressure is high, air is sinking and pushing on the ground. That same air must eventually rise because it has nowhere else to go. When it rises, air cools down and moisture condenses. With that condensation, barometric pressure goes down. [source: Shutt]
The exact effect barometric pressure has on bass, if any, is not altogether clear. While there is very little scientific information to be found on the topic, many fisherman swear barometric pressure plays a large role in whether or not a fishing trip will be successful. And their specific theories are abundant.
In the end, most of the theories come to the same conclusion. When barometric pressure is at a high, bass fishing will be at a low, especially in shallow waters, where changes in pressure are more easily felt. [source: Adams] Some say that the bass swim bladder is sensitive to changes in air pressure.
When barometric pressure is high, the swim bladder feels increased pressure and the fish becomes slow and tired. [source: Extreme Bass Lures] Other anglers fail to explain why it occurs, but agree and claim bass fishing will be at its best during times of dropping, low or slowly rising pressure.
It is important to remember that these are still just theories, and there are some who believe pressure has little to do whether bass will bite. But hey, who better to trust than people who have experienced the highs and lows firsthand? The consensus among those anglers is to avoid fishing when barometric pressure has peaked.