Question No 1 [AIP ENR 1.1 para 10.7.2.3 & 10.7.2.7 (a)] (ATC AU-302 3.2.5 & 3.2.3)
A private IFR flight is planned to arrive at Adelaide at 250615 UTC. The destination TAF3 includes.
FM 250500 23020KT 3000 +SHRA BKN020
The nearest suitable alternate is 120 minutes away. The minimum extra fuel required to satisfy any alternate or
holding requirements is-

[a] no holding or alternate is required because arrival is within the first 3 hours
[b] 60 minutes holding is required
[c] 120 minutes alternate fuel is required
[d] 30 minutes holding fuel is required

ACVWPLS

3000 VIS is below alt for any AD in Australia.. usually its 4.4 vis for an alternate

TAF3 purely means you don't need a 30 min buffer before and after the first three hours

OPR ALTERNATES ARE STILL NEEDED ON TAF3

Thanks for your feed-back. I've changed the arrival time in that question to 250440. That makes it within 30min of the commencement of the FM but, because it's a TAF3, the 30min buffers do not apply within the first 3 hours. You don't need an alternate.

For this question, how do we know the arrival is within the first three hours of the TAF3? All we have is the FM part of the TAF, but we aren't given the TAF validity start & finish times, so how can we assume we don't need to account for the 30 min buffer when it's possible that the TAF started more than 3 hours before the FM?
Thanks