Interpolation and QNH
Observed values are rounded down.
ie. Decimal values don't appear on a TAF.
Anyway, 15' isn't going to affect it
that much.
Play nice, kiddies.
Tweeky,
Since when has ASL been able to keep up with rule changes?
Major changes to IFR rules 9 months ago that I bet still haven't been switched in IREX.
If you get an answer wrong because of expired rules (your AIPs current, their answer not), you have the right to appeal.