Oh c'mon guys, get real.
Hmmm...
For navigation you'd be better off looking at the ground wind at the start of your flight and making the speed and direction adjustment for winds aloft. Please, at least do this to check that what the F214 told you is still right.
T'other way round I should have thought (in any event, I find it difficult to imagine the winds aloft from a distance of 100 miles on a long cross-country!!!)?
These things are to give you an idea of how the atmosphere is expected to behave in a general sense. Not to give you an accurate wind vector for flight navigation purposes.
It's the best information available - and should be the basis of calculation for all flights, especially flight tests and 'qualifying' flights.
Apart from wind velocity, how would you know what the temperature will be at your planned level/altitude, unless you 'suck it and see' and depart regardless?
Maybe not too much of an issue if it's a summer's day and/or you can guarantee VMC and have the knowledge and experience never to be caught out - for the rest of us it would be preferable to know prior to departure what the freezing level is forecast to be.
