If it were as simple as that I wouldn't be asking. I ask because it is not in the Ops manual; the wording says that met reports & forecasts will indicate that the weather will be at or above the applicable planning minima. This does not preclude tempo nor prob30 since they do not indicate what the weather will be (only a probability of a temporary deterioration). Should your Astraeus ops manual be more specific I would be grateful if you would let me know, and whether it is a company introduced rule or if it is mandated somewhere. I agree that arriving in the tempo and/or prob30 causes problems, but nothing that suitable holding fuel shouldn't help solve.
The consensus (overwhelmingly so) at work is that tempo and/or prob30 below minima need not necessarily be taken in to account, but like me they can't recall where it is written and if it isn't specifically written then what the logic is for the derivation.