(myself, eiterorm --- see above)
And about drawing and ignoring Mythos cards for the sake of it. This only has a purpose if you, as a consequence of this, either
1. draw "The story continues…", such that the deck is reshuffled.
2. end up having cycled through the entire Mythos deck.
In all other situations, drawing and ignoring Mythos cards will have absolutely no effect on the game. So unless one of the two situations above occur, the probability of drawing a gate burst, for instance, will be exactly the same whether or not you draw and ignore those cards.
This is obviously a mistake, and I just want to correct this. As long as "The story continues…" is a part of the deck, situation 2 will never happen. "The story continues…" is always inside the deck, so you will always find "The story continues…" before you cycle through all the Mythos cards.
I see the loop point you're referring too, but still, I'm not 100% with you. Basically, I believe that since you're resolving an encounter, is the encounter that "takes precedence", while if you were resolving a Mythos card, it'd be the AO ability to "command". So, the encounters instructs you to draw Mythos card until you find a Wehather environment. You do it. But then, since you cannot put that card into play, you discard it without triggering the second part of Cthugha's ability (that was written referring to a "what shall I do when I draw a Weather card during the Mythos Phase") and break the loop.
Still, no rules behind my answer, it's just the way I'll solve the conundrum
Well, let's just look at the numbers. In the base game, there's 67 Mythos cards. In the Innsmouth expansion there's 36, adding up to a total of 103. Of these 103 there are 10 Weather cards. So if you were to draw and ignore Mythos cards until you get a Weather card, you'd be expected to draw 10 cards. Let's assume that you've already played 10 Mythos cards, none of which were "The story continues…", such that there are 93 cards remaining in the Mythos deck. If you draw 10 cards out of these 93, you will have an 11% chance of drawing "The story continues…". Of course, drawing and ignoring 10 cards will increase the probability of drawing "The story continues…" later in the game, but just how many Mythos cards will be played during the game? If you draw 52 Mythos over the course of the game, you have a 50% chance of "The story continues…" ever showing up during the entire game. But when do you ever play that many Mythos cards during a game? The probability that drawing and ignoring Mythos cards will have any effect on the game, is too low for me to bother. I'll just draw a new encounter instead. ;-]
EDIT: What's wrong with the forum? Why can't I quote people?