Watts jumping like a rabbit

1. In outside riding, when you can't be looking at the PM as often and road conditions, wind, terrain, etc. are constantly changing, power will tend to jump around a lot more than indoors on the trainer. You can set the PM to display average watts over different (short) time intervals like one, three, five seconds, etc. Might help to use a longer interval outside. In general, keeping a steady power despite different conditions is a goal; in reality, it's never going to be as steady outside on the road as on a trainer.

2. Normal for power to change when changing position. Mine is always a bit higher inside on the trainer if I get out of aero and sit up. But outside, I'm usually going faster at the same power in aero, which makes sense, because I'd be more....aero.

3. I also can hit higher watts out of aero; if a workout calls for sprint-type effort on the trainer or big-gear intervals, I generally don't do them in aero unless my coach specifies that. Probably you are more efficient in that position, at least in terms of being able to push bigger gears without serious discomfort--in your case maybe from arthritis; in mine probably due to low body weight and limited strength. But on the road with wind, higher watts may not translate to higher speed. In aero you should be able to push higher speed with lower watts.

4. I wouldn't bother with watts/kg. on your screen. It's more a metric you might use to gauge progress on periodic FTP tests rather than day by day, since your weight probably won't change much on a short time scale.

5.Not sure. Most power-based workouts will specify a certain number of minutes at a particular % of max (as determined by an FTP test) or maybe a specific range of watts (if a coach has written them for you based on your level). Typically there are intervals of harder riding followed by recovery intervals at a lower % of FTP.

Hope this makes some kind of sense. No doubt the bike experts will chime in with the technical stuff.

A PM is a wise investment. Congratulations

I suggest you also get a book and do some reading. You will get the most out of your investment

Coggan's book is kind of the bible but a little complex at times for the beginner.
Skiba has a great book which is a bit simpler.

Both are great resources.

To efficiently train with power, eventually you will do some type of testing to establish your threshold. Then various intervals, race pacing, measurement of training load ......will be based on that threshold. This is all explained in either of those books

Most people can generate more watts out of aero. If the difference is too great however it's probably a combination of being used to it and fit.

Thanks a bunch. I have Joe Friel's training Bible and it has a bit on power meters so I'll start with that and see where I go.