Understanding pressure systems

As we move out of summer and into fall, this transition period means weather will be a major factor in the activity and behavior of the fish.  As anglers, we need to be prepared for just about any type of weather, even if our trusty old weatherman doesn’t call for it.

This time of year, the jet stream shifts pulling cold arctic air down towards the south, and high and low pressure systems will collide.  This collision course creates increased wind and fronts and as the pressure systems overlap, clouds will begin to form and potentially rain will fall.

One of the main factors that makes the wind blow are those high and low pressure systems.  Wind in itself is simply the movement of air, which is after all a fluid, just like water.  It’s the high and low pressure systems that force this fluid to move.

Take a balloon for example.  The air inside of a balloon is the high pressure system and the air outside of the balloon is low pressure.  If you pop the balloon the high pressure escapes to the low pressure areas, this holds true with the atmosphere.  Air wants to move away from high pressure to areas of lower pressure.  In fact, the stronger the high and the stronger the low the faster the air will move.  This is called the “pressure gradient”.

Understanding high and low pressure systems imgWind plays a major factor in fishing all over the world and in different ways depending on the position and latitude and longitude co-ordinates of the body of water.

Take for example Lake Erie.  Historically speaking, October and November are the windiest months out of the year.   As that cooler northern air gets pulled down meeting the warm southern air, the low and high systems meet, creating wind and fronts. Unfortunately for Lake Erie, this can happen close enough to create those 20 – 25 mile an hour winds northern anglers are used to seeing in the fall.

Unlike in most reservoirs in the south, Lake Erie is a Natural lake and there really is no place to hide.  Sure, you can fish the rivers, but with high winds usually means muddy water and mud and smallmouth just don’t mix!

South western and western winds usually blow the majority of the time in the fall in the Lake Erie region.  Due to its long bowl like shape, lack of hiding places and it seemingly being the meeting grounds of the high and low pressure systems, Lake Erie fishermen experience that “pressure gradient” more often than you can shake a fishing rod at.  Getting out and enjoying one last outing before the ice pushes fishermen off the water can sometimes be a challenge.

Other major fisheries around North America are effected greatly by wind, much like on Lake Erie.

Understanding high and low pressure systems Lake ForkTake for example Lake Fork in Texas.  Late winter to early spring, right before the bass move up to begin their spawn, the northern wind roars usually making the main lake unfishable.  Unlike Lake Erie though, Lake Fork is a reservoir with many small feeder creeks, so finding solitude isn’t that difficult.  Deep valleys with higher than normal elevation levels creates a nice little hideaway for anglers seeking the spring time bite.

Hop on a plane and fly cross country to Lake Okeechobee and that is another lake that can have wind issues.  Weather systems tend to take advantage of the state of Florida’s pancake like landscape and when the wind rolls..it rolls!  On the windiest of days, leaving the confines of the cane can be a challenge for any angler.

Although strong winds and pressure systems may be our enemy, they can also be our ally.  As the low and high pressure systems meet, the barometric pressure will rise.  Before and even during a storm is usually the best time for fishing.  As the eye of the storm reaches and then passes, the barometric pressure will drop, which usually creates a drop in fish activity and fishing will be difficult until the weather stabilizes.

Small doses of wind also play in our favor, as it pushes sediment and plankton around, which moves the bait fish and ultimately the fish.  Offshore humps and windblown shorelines become our best friends, as the fish are now more predictable and will wolf pack together in these areas.

In most cases throughout the year, utilizing the forecast and understanding how the fish will react and where they will be is just another tool and can help you catch more fish.