Understanding Barometric pressure key to patterning big bass

Recently I was having a discussion with my friends Gary Dobyns, Mike Barone, and Goodyear Pro John McGoey about the significance, or lack thereof, in the relationship between barometric pressure and bass fishing. In 2004 I began journaling my fishing trips, and trying to gather as much data from the internet as I could find. Frontal systems, wind direction, moon phase, etc. Among those conditions I found research that suggested that the ideal barometric pressure for bass was roughly 28.5-30.1. In the ten years of data that I’ve collected, the most significant correlation that I could see between feeding activity and weather was when the barometer was falling from 30-29. That’s hard evidence, from over 150 total entries, with all data from that period provided by Weather Underground.

Pretty indisputable if you ask me…

jim with smallmouth bass

At first I was amazed. The amount of fish I caught during those sweet spots was too significant to deny. Not to mention the size of the fish was just incredible. The more I began to study that and understand it, the more I could start to manipulate my tactics to support the conditions that I was in. Let me explain: barometric rises and falls with the presence of high or low pressure systems. How fast it falls and how much tends to vary from one system to another. Now for the past 10 years, there was not a single weather website I could find that was trying to predict this condition. That would leave me to have to use the hourly forecast to predict when the storm would arrive, and monitor the current conditions at wunderground.com (I’m going back to the days of pre-smartphone apps). While the pressure was high I would finesse fish: shaky heads, drop shot, small spinnerbaits, Texas-rigged soft plastics, etc. As soon as I saw the pressure start to fall I’d switch to reaction baits, and target big bites. I can’t tell you how often this allowed me to do well all day, rather than wondering why my fish “shut down” or stopped eating what had seemed to work all day long.

There are a lot of people, especially when you’re referencing deep water fishing (25 feet and deeper), that will tell you bp plays absolutely no part what you catch. While I won’t agree on that, I will say that the fish that are located deeper than 20 feet, in my experience, have proven to be impacted by pressure less than fish in 5 feet or less, but that comparison is really skewed from the very beginning for several reasons. For the most part, largemouth bass don’t typically live in water over 20 feet for prolonged periods of time in the summer months. Any fish that’s caught 20 feet or deeper is already subjected to pressure far greater than shallow fish of the same species. From my own experience, smallmouth are the fish that I’m catching in water deeper than 20 feet, and they’re always better about eating than largemouth anyhow. So naturally you might not see trends as significant in those brown fish in comparison to their green cousins.

weather underground forecast
Weather Underground Forecast Tools

As I said, for the past 10 years nobody was predicting barometric pressure. Was being the key word in that sentence. With the conversion to their new website platform, Weather Underground now has a completely customizable graph that will show you the 10 day or hourly forecast that includes chance of precipitation, wind direction and speed, humidity, cloud cover, dew point, and…barometric pressure. So now I can make a note to myself that I’ll expect my best fishing times to be between this time and that time, and allow myself to have a really solid game plan before I launch. Now to be fair, I’m not saying this will make you the next KVD. But it has certainly helped me catch more and bigger bass.

3 COMMENTS

  1. Thanks. With 10 years of supporting data, I’ll be adjusting my presentation and lure selection the next time I find the bp dropping. I had been convinced that bass shut down when a low pressure system moves in. This was based on my casual observations when I was living in Florida. Having moved to Kentucky, I’ve heard anglers here like it when the bp drops.

  2. Great article, thanks for the info! I have also found that 9 times out of 10 falling pressure means clouds moving in, and high pressure means bright sunny skies. From my experience, the shallow bass bite better when it’s overcast (most of the time). It seems that after a period of high pressure and bright sunny skies that the fish turn on under cloud cover, even if it’s very brief. The rise and fall of barometric pressure and cloud cover are very closely related and I believe those magic times when you load the boat in five minutes, sometimes while one little cloud passes, are the perfect combination of the two.

  3. That is a great article. I’m new to fishing again and have noticed fish activities before and after it rains. Now that makes sense as to why. Thanks for the time you put in.

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