The model is definitely oversimplified, because there's data we just don't have. But I assume (I have not verified) that this is a quantitative problem, not a qualitative one: With more complete data, the numbers and the plots should move, but there should still be straight-line solutions and/or constant-altitude solutions, just at different altitudes/headings/speeds. I’m happy to try out a different set of inputs to see if that’s the case, but some data will always be missing.Since (as markus said), the wind can be different at different altitudes (and even with distance, although less so), just using an assumed wind of 0 is an oversimplification. However you can assume it does not change for the jet (i.e. a local wind speed of 0) then the local wind for the object and the clouds is just a component of their velocity. It's the relative speeds which are important. You can translate that to a ground speed by adding in an arbitrary jet-local wind velocity, but it won't make a huge difference. The first goal would be see what the possible relative motions are.
However we do have one datapoint of "120 knots out of the West", which is probably the jet-local wind. So you might as well use that.
Broadly speaking, the downward camera angle sets the constraints on that. The clouds in the video looked to me like stratocumulus (I have a little background in meteorology), stratocumulus being very common over water and generally the most common cloud type globally, and they typically top out at 5,000–7,000 feet. It turns out, If I point a 25,000-foot camera at a large cloud layer at 6,500, tilting the camera down by 2.22° (and keeping it there) reproduces the clouds in the FOV surprisingly well.I'm sorry if you posted this before, but how do you know the altitude of the cloud layer? Is it an assumption? If so it seems a very important one.
But that’s not the only way to do it. A “secret admirer” on Twitter did his own simulation and put the clouds at 23,000 feet (altocumulus, presumably):
If I do that in my model, the camera, anywhere between 1.5–2.5°, doesn’t see any sky at all; it just points at the clouds. I assume that my friend made the cloud layer end along a very convenient line in order to make the sky reappear. That indeed may have been the case on that day, and it changes things a lot — but it’s inventing data, and I don’t think that’s helpful or warranted.
My Twitter friend mentioned (several times!) that the range for the ATFLIR is listed at 40 NM, and the clouds in my FOV are some 90–120 NM away, while his are much closer. But the ATFLIR isn’t locked on the clouds. In my Scenario #5 and others, the object it’s locked onto is well inside that range. The camera can't help that there also happens to be stuff in the background.