Diverting to non-planned alternate
Hi, just a general question about alternates in EASA land.
Flying a light turboprop, one of the routes I fly goes from A to B to C.
Leg A-B is just over an hour, while leg B to C is under 10 minutes.
Neither airport B or C have TAFs, so I need to have two alternates. If we have a full flight on the first leg, I cannot use A as an alternate (too far away), so we use airports D and E, which we do not have any handling at.
If I fly leg B to C, and decide to divert, am I obligated to choose between D and E, or can I divert to B, even though it is not in my atc flight plan? B is much more practical, and even though weather is generally the same at B and C, B has an ILS, so there is a good chance I would be able to land at B. Would I need to plan extra fuel for that? If I go with min fuel according to flight plan, choosing B would rule out at least one of the other alternates.
By the way, this is really only theoretical. Both airport B and C issue METARS, and we wouldn't really depart B unless we knew we could get into C.
As a secondary question. As airport C is so close to B. Would I actually require two alternates assuming METAR weather is good? I know there isn't technically a forecast, but as flight time is so close, could the METAR be considered the weather we will get on arrival?