On the subject of several miles away, what about a weather balloon
launched from Cornwall on a day with a strong westerly wind?

The resulting readings can be plotted on a tephigram labelled Camborne
03808, but by the time the balloon has reached the 300mb level it might be
vertically above Bognor.

And yet we are supposed to say "bugger Bognor, we will still call it the
Camborne ascent".

That will soon change. The TEMP code's days are numbered now, as it will
soon be superseded by a binary BUFR code form. This new code form has
"levels" like a TEMP message, but each level has latitude and longitude
data - so the concept of assigning all the data at the various levels to the
location of the launch will not exist. That should help with model
analysis/assimilation cycle and, consequently, accuracy of model
predictions.
--
Freddie
Bayston Hill
Shropshire
102m AMSL
http://www.hosiene.co.uk/weather/
https://twitter.com/#!/BaystonHillWx for hourly reports