question about crappie behavior/migration:

I was pondering the meaning of someone reporting "the crappie are off the trees". What do they mean? If not on the trees (brushpiles included, I presume), then where? Suspended deep? Is this why long-lining is recommended? The crappie are suspended in deeper water? Last week I found plenty crappie on trees (Oconee), but the surface water temp was 61F that day, and since the big cold front, is probably in upper 50s now.

As I have read, crappie go deep in too warm (above 80F) or too cold water (below 50F) as a generalization, and so are supposed to be moving deep this time of year as water temps drop thru 50. I realize the many other factors such as water level, bait moving up the creeks, have a lot to do with it, so this question is mainly "why and when" long-lining becomes more productive than timber dippin' or brushpile fishing in the fall? I realize many long-line all the time, but when does it really get good in the fall, and any reasons why?

The spawn transition is a little easier to understand to me.

I went to Thomas Mill Creek on Eufaula yesterday to try out the new H-bird Piranha. This is an upgrade from a mid 80's Eagle Fish ID, which still works, by the way. The wind was blowing from the NE, and a bit strong for my rig. Regardless, the fish were out near the mouth starting at 30 then up to 40 fow, and holding just off the bottom. There were fish on what brush and logs were there, and on the humps, with many more where the channel sides leveled off at the bottom. The surface temp was 59.

Will they move further out with colder water?
Maybe 6 to 8 seen up the creek in more shallow water, and all on tops.

If it was shad I was seeing, they was in the channel, too.

Thanks, but I must admit to having never fished Eufala (yet). Is this what you think is seasonal behavior, and how? Sorry if I don't understand.

It was my first visit at Eufaula after recently moving to this area. I think that it is seasonal and predictable from searches on the web, and past observations. The area I moved from, the upper Black Warrior River, NW of Birmingham, had depth, but also had current at times. With current the crappie moved into the creek mouth. When generation stopped at the dam, they disappeared. The water in the mouth of the creek was not as deep, but current was minimal compared to the river. With more cooling I predict that they will move closer to the river channel as the deeper water will likely be warmer there. Bream fishing on the Mobile River Delta where I grew up revealed the same behavior. Hot and cold months the fish were deep, to a point, but 30 feet was not unusual if there was that much water, and shallow spring and fall. In some smaller creeks we fished out of the other side of the boat as the fish moved to the center or shore depending on the season.
Granted, I have not been much over 10 feet under the surface, and that swimming during the summer, but it was noticeably cooler than the quite warm surface water, which was more like bath water during the hot summer months. I am not sure how much difference there is in temp at that depth, and it seems that the shad are close by. Correlation, causation, or both? A guess is that the fish, crappie and shad, are searching for the warmest temp and most oxygen concentrated water for metabolism and energy management.
Having no experience with long lining I can offer no comment

When the crappie move off the timber this time of year you will be able to find and catch them in the channels, flats, coves, etc..
In my opinion when that happens it is much like fishing pre-spawn and the long lines work good because you don't have to deal with all the hang-ups. I also think that the optimal time is when the water is in the 53-58 degree range both spring and fall. It's all about the crappie following the shad. I've experienced excellent fishing from around Thanksgiving to mid December just depending on how long the water temperatures stays in the range mentioned above.