"Matt Barrow" writes:

[...]
Funny, after 20 or so replies, no one has answered the original question,
[...]

The original point was that +/- "ATC uses reading front reporting
stations on hill tops, rather than from stations nearby in
valleys". Gee, I have terrain over 13000 feet high just a few miles
from here, but they (ATC) use the Montrose or Grand Junction station
readings.

And what exactly is your question now? Why your local ATC does that?
Maybe there is no more better observation station higher up, even
though that would yield more accurate altitudes there.

As you seem to forget, you doubted this point, and that caused the
bulk of the thread. To quote you: "How would a station be more
representative if it was/wasn't in a valley or on a hill top?", and
"You're still not explaining how a ground station at, say, 6000' MSL
would be have a more accurate baro reading than one down in a nearby
valley at, say, 2000' MSL. That is the point of the thread.".

Maybe for en-route purposes, or with their weather patterns, it tends
to be close enough. Maybe they don't want to issue a separate
altimeter call for people doing approaches into the lower areas. Call
and ask them if you really need to know.


- FChE