Do you honestly sit there and look at the TAT every 3 to 5 seconds though?
No, but I keep an eye on it while flogging around in forecast
severe CAT areas at CAT levels. Mostly, temp trends (high to
low or low to high) are slow which usually means only mod
turb, but sudden 3 degree jumps or more is like slamming
into a brick wall a few secs later.
I've done a lot of China/Japan/trans-Pacific/Europe flights for
many years and one tends to pick up the clues. The best idea
of course is to stay low and keep out of it, but that's not always
possible.