I'm pushed for time, but the key point is that normally you use your departure a/d as the alternate unless it has an approach ban in force. ie unless the rvr is down to 5-600m (cloud base is a discussion point in its own right). If that is the case then in the UK they do indeed use alternates an hour away. Having said that, there is a CAA dispensation to use on a/d more than an hour away as it is on the other side of the country and therefore in a different wx system; one problem is that if Abn is down in fog, so are most of the ususal 60 min alternates.
Must go, hope that helps a bit..
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Another day in paradise