"JT Wright" wrote in message
...

The altimeter setting value does not take into account the temperature.
The
temperature profile of a "standard" atmosphere is assumed. The SLP takes
into
affect the actual temperature reading (12 hour mean temperature average).
So it
looks like the difference between these two readings can be greater at
higher
station elevations.

That's right. Bear in mind that SLP is somewhat theoretical, in that you
don't dig a mineshaft down to sea level to check it. :-) In some senses so
is altimeter setting.

I think the reason for having SLP numbers is so that you can plot higher and
lower elevation stations on the same chart without getting anomalies. If
you used altimeter settings, then on hot or cold days the high elevation
stations would stand out, because their altimeter settings would be much
higher or lower than low level stations nearby.

Julian Scarfe