On Thu, 06 Feb 2020 20:17:31 -0000, Commander Kinsey wrote:

Because the pointer shows good weather to the right of centre and bad
weather to the left, with the centre being nominal pressure. But that
nominal pressure varies with altitude.

Which is why you have to compensate for altitude. Current standard
pressure is about 1020 (Set Fair). Current real pressure is 970
(Stormy). The weather is dead calm, clear and dry. ie that associated
with 1020.

There is no way to adjust the barometer for altitude.

Crap barometer or you've not found tweak yet.

--
Cheers
Dave.