Contrails And You

[dayhut]

Has anyone done a in-depth discussion on contrails?
I've been wondering about how to explain their presence/meaning, as it relates to atmospheric moisture and its impact on light penetration.
This, of course, is one of the factors that result in movements of fish from sanctuary to the shallows.

I remember Buck saying we don't wanna complicate all this weather jazz trying to remember too much. Keep it simple, stupid....

Since contrails are both observable and can at least indicate potentially good conditions, what emphasis can we place on them?

David

[Steve Craig]

Their presense pretty much simply indicates that there is a moisture build up in the atmosphere.
As more and more moisture builds, the high cirrus clouds, and the trails get thicker. When this takes place we can usually associate this with less light penetration into the fishes world.
The more and thicker this becomes, the more the light refracts and the less penetration.
This translates into shallower migrations of the fish, and longer movement times.

Many times however, this is NOT the case. For instance if this begins to change to quickly. Here in AZ. I have seen this built up happen the second day after a servere cold front. Like Buck always said, the fish can adapt and handle change, but a CHANGING enviorment, will send them or keep them downstairs for a while until things become STABLE.
This same buildup over several days is to be preferred.

HOWEVER........
I have also seen and experienced mile high skys and great long lasting fish movements. The reason.......
A long STABLE weather condtion.
Again, here in AZ we can have many days and even weeks between cold fronts. The sky will look cloudless with very little if any high cirrus. But this condition allows a very stable enviorment and very good fish movements. But let even a DRY cold front come though, and downstairs they go!

So those trails are simply good inticators for us. I once remember Tom Coleman telling me that he and Buck were fishing under a post frontal condition and off in the distance Tom noticed many clouds developing. When he pointed them out to Buck, Buck looked up, and simply said, "False hope, those are too far away and not enough moisture in the air"!

[jwt]

David, Buck left out the information about the formation of contrails because, other than the fact they exist and what they indicate, it doesn't add anything to ones fishing knowledge. The paragraph below will give you some insight into the formation of contrails; Interesting if you are interested in meteorology(as I am), but useless for fishing.

Contrails (short for condensation trails) are line-shaped clouds produced by exhaust from aircraft engines or by changes in air pressure, typically at cruise altitudes of aircraft; about 30,000 to 40,000 feet. Contrails are composed of water in the form of ice crystals. The combination of water vapor and pollutants in the exhaust from aircraft engines and the low temperature, approximately -48° F to -70° F, that exist at high altitudes allows the formation of the trails. The exhaust from aircraft engines contains impurities from the fuel plus water vapor, which provides the particles that serve as sites for the growth of ice crystals. As the water vapor in the exhaust is introduced into the frigid air it condenses(actually it sublimates) into ice crystals that compose a contrail, which falls a considerable distance before evaporating. If the air at the flight level is dry, i.e. low dew point, the contrails tend to dissipate, but if the contrails persist and spread out into broad bands it indicates warm humid air. Formation of contrails can also be triggered by changes in air pressure in wingtip vortices or in the air over the entire wing surface. Contrails are actually Cirrus clouds.

Cirrus clouds and persistent contrails normally form at the leading edge of a warm front as it overrides a cold front, i.e. warm air advection, and that's why Buck emphasizes them as a sign of improving conditions.

[Sonny]

Thanks, interesting.



Sonny

[John Bales]

David, You just answered your own question. Your observations of what exists upstairs can tell you a lot of what you can expect. You can SEE what is happening as you start out, throughout the day and see exactly what took place when the fishing was at its best. You should observe upstairs every time you fish and pay attention all day long. Wind or lack of wind can also play a part in fish movements. Waves break up light. You can bet your life that when the fish become active, there will be some kind of light conditions change. You and I may not be able to see it happen every time but if you pay attention to everything around you, many times you will see that the best part of the catching occurs during some kind of change in the light condition. On another note, you can only relate the two if you catch the fish. John