Pacemaker Fishing Forum

The following write up is from Capt. Matt Tawes, an excellent fly fishing guide from the Chesapeake Bay.

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"Weather Factors for Fishing - The Affects of Weather and How best to Deal with Them When Fishing."

We’re all aware of how the weather plays a role in fishing…right? Sure, we all hate it when the weatherman forecasts wind or rain when planning our next fishing trip.

However, how many fishermen really know what affect changing weather conditions have on fish (the way they react, feed and so on), and better yet how to deal with the conditions and still catch fish.

My goal in writing this is to put into laymen’s terms what these so-called meteorological events have to do with going fishing.  Well, there is no really simple way to explain clipper systems, warm fronts, cold fronts, isobars and barometric pressure but knowing what affect they have on fish is yet another key to having a successful day on the water.

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"Fishing in the Rain & Wind"

Rainy conditions are typical in the spring (usually March, April and May) and just as the water is starting to warm up it will rain for what seems like days and cool things down again. Heavy rain also over time will freshen the water (decrease its salinity) and in the bay and surrounding tributaries it will often make a mess of the water with run off (cloudy muddy conditions resulting in poor water clarity). Of course fresher cooler water and low salinity send fish a little deeper at times, cloudy to dirty water is not really preferred by any species especially Speckled Trout but Stripers are a little more tolerant. The resolution is to fish deeper and look for clearer water. Fish will often hold on the edge of dirty to clear water and at a thermocline or depth where the temperature and pressure better suit them (we’ll discuss the effects of pressure in the next section).

Wind can be an advantage and disadvantage. Some of my best fishing has come on windy days. Fish tend to like choppy water, lesser species and baitfish are less able to fight strong currents associated with wind and therefore get tumbled in the current or cannot out swim their prey making an easy meal for the fish.

The fisherman can take advantage of the wind which diffuses the water’s surface clarity (making their overhead presence less visible to the fish). A great place to target fish is against shorelines and points where the wind is rolling waves against the banks. This wave action makes these spots prime hunting grounds for fish chasing bait thus making it prime for fishermen as well. The disadvantage on the other hand is that over time the wind can make the water turbid and cloudy sending fish in search of cleaner water in which to hunt their prey. As mentioned above just look for the dirty/clean water line or fish deeper, fish often go to the outer edge of flats or cover looking for clean water and also may hold in potholes or troughs.

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"Barometric Pressure and Fish"

Warm fronts and cold fronts as described above affect the temperature and winds and are associated with low and high pressure. Of course over a prolonged period changes in air temperature will affect water temperature but during the short term they only have a marginal affect or change to the water surface temperature. The real affect during the approach and passage of fronts comes with the change in barometric pressure.  All fishermen know that as weather changes it seemingly has an affect on fishing some short term and some longer term.

Well, the reason it affects fishing is explained in barometric pressure or rather the rising and falling of the barometer. Changing weather impacts whether or not we go fishing depending upon how severe the weather but fish are already wet so they don’t’ really care so much if it rains, they like to swim in the waves and current so they don’t care about the wind that causes it to be rough. What fish are concerned about is being comfortable and finding food.

Have you ever heard of a swim-bladder in fish… of course you have. What I bet you didn’t know is that barometric pressure affects a fish’s swim bladder. That’s right; air pressure affects fish under water.  Barometric pressure is one of the most talked about but least understood factors that affect the way fish act.  Learning why fish eat one day and don’t the next is often the mystery.

Let me explain in a little more detail; first lets address a little scientific data. Barometric pressure produces a lot less pressure on fish than the water does but it does affect them in shallow water. The entire column of air above the earth’s surface is defined as weighing one atmosphere. To move from the surface of the water to let’s say 16 feet deep is also one atmosphere of pressure. The small amount of change in pressure caused by a frontal system is less than the pressure of a fish swimming down two feet. Basically a fish can withstand 10 times any change that barometric pressure causes and the deeper the water the greater the pressure compressing their swim-bladder. Now let’s take a closer look at the biology of a fish. The fish’s swim bladder is a gas-filled sac that controls buoyancy, if a fish starts to descend, the increased pressure from the water results in a compression of gas inside the swim bladder. If the fish swims shallower there is a decrease in water pressure and so the gas in the swim bladder expands. Where barometric pressure comes into play is when the pressure changes suddenly as it does with the passage of weather fronts (warm= low pressure & cold = high pressure) these sudden changes affect the pressure on the fish’s swim bladder (again more so in shallow water) thus making them uncomfortable (due to the expansion of their swim-bladder) and less interested in feeding (or chasing your lure/fly) and more interested in finding more stable pressure found at greater depths.

Is your head spinning yet or is your brain cramped...while researching this phenomenon for facts mine was. Irregardless of whether you understand and can follow all of this data it does in fact offer the explanation of how weather and the barometer (the rise and fall in pressure) affect fishing.

Some general guidelines for dealing with the affects of barometric pressure when fishing are as follows:

Pressure                             Type of Weather                     Affect on Fish                            Techniques/Tactics

High                                  Clear Skies/Bluebird days         Fish are slower and lethargic.     Don’t expect high numbers. Slow your
                                                                                      They hold tight to cover or          presentation. Target cover and deeper water.
                                                                                       in deeper water.                        Fishing S-l-o-w can spell s-u-c-c-e-s-s!                                                                                                                                               
                                                                                                                                                                                                                                                                         
Rising                                   Skies clearing and weather      Fish are starting to become         Fish with brighter lures/patterns and
                                          improving.                             more active.                              near cover/structure. Work varying depths.

Normal to Stable              Fair                                         Normal fishing.                          Experiment or use your favorite lures/flies.

Falling                                   Conditions starting do decline.  Generally fish are more active    Speed up your presentation. Work topwater lures
                                         Approaching front.                  and feeding.                              and fish shallow. Pack the rain gear just in case

    
Slightly Lower pressure          Usually overcast or cloudy.    Fish generally move off cover,    Work the shallows with moderate speed retrieve.
                                                                                      chase bait shallower and will
                                                                                      become more aggressive.    

Low                                  Rainy and Storms                      Fish are wary, become less         As action subsides try fishing deeper,
                                                                                      active the longer these               head for the dock, go rent a movie
                                                                                      conditions exist.   

Let’s face it there are compromises with everything in life fishing is one of them. It’s near impossible to have perfect weather and conditions most of the time and we’re going to have to deal with the conditions Mother Nature deals out if we expect to go fishing.

Armed with a little knowledge we can make the best of most conditions so know your areas, and watch the weather on TV or listen to the weather channel on your VHF. With some preparation and common sense (knowing when to stay in or call it a day) will make your fishing trips more successful and enjoyable.

Notes: I’m no weatherman, nor am I a fisheries biologist. Information stated above is from my personal experience. I did research both in terms of meteorology and biology science throughout the internet and other sources which were deemed both credible and accurate.