Need some help filling out an adventure

[ASquirrel258]

So for the last few years, my player group has basically taken turns GM'ing games. My friends does adventure paths, while my game is homebrew. As a GM, I have an easy time creating the overall idea for .... chapters or maybe Modules would make it easy to compare to Paizo material. I have next to no problem coming up with the BBEG, the reasoning behind whats happening, and the creation of encounters. My big problem is filling out an adventure. Making it more that just two or three encounters. So what I'm going to do is tell what my current project is about, and hope some of ya'll might be able to help me fill out this chapter. I'm hoping to learn a thing or two to help with future creations. So here is what I've got:
A certain cliff side village is on the verge of being battered every year by a horrible storm, like a very powerful hurricane. And every year, the storm mysteriously breaks or turns back out to sea before it can cause any major damage or hurt anyone. The secret behind this is that this storm in particular is represented by the BBEG which I have called The Embodiment of the Storm. There is a now old man in the village whose purpose for most of his life was to be there when the storm comes a calling, and defeat the Embodiment with an axe called the Storm Breaker. This does not defeat the Embodiment, but does send him, and the storm, away. This year though, some accident had befallen the old man and he has had to send for help from a nearby Guild (the Players). The players are, of course, meant to take up the old mans job and defeat the Storm. I really like this idea, and I think they will find it pretty cool. My problem is..... I don't quite know how to make this last. Do any of you have an idea on how I could fluff this out a bit? I would really appreciate some advice.
By-the-By, if anyone is interested, the inspiration for this adventure came from the Drabblecast podcast episode 131- Storm Comes A' Callin'.

[Watery Soup]

You can add some urgency my shifting the time frame a bit - the storm has already hit and the PCs are summoned not to break the storm but to evacuate or rescue. In the course of helping, they learn about the old man, and then from him, they learn about the axe.

You'll also need to tie off the story in the end, unless your PCs are okay with becoming the permanent solution to a yearly problem. For instance, maybe they can't use the axe themselves, they have to find the Chosen One (a young child), who is the only one who can wield the axe. Or they realize that the storm retreats out of self-preservation and they have to chase the storm out at sea and finish it off in its lair.

You can plan for a plot twist. Maybe the old man turns out to be the BBEG - he's an exiled storm prince who stole the scepter of power (the axe) and the storm king is here to recover it. Or the old man and the storm are lovers and this is a 40-year-old lover's quarrel. The old man chases the storm off because he's still mad, but not mad enough to kill it.

[Quixote]

First, I'd suggest reading everything the Angry GM has to offer (on adventure- and encounter-building, specifically, but then everything else).

Second, if you're looking to fill this idea out a bit, you could consider:

-a small cult that worships the storm; maybe they don't know who carries the Storm Breaker and are trying to find him. Maybe they've already captured him.

-mermaids/sirens/selkies who, no longer held at bay by the artifact's magics, roam the local waters, preying upon wandering villagers.

-a stretch of research in the village's moldering archives for clues as to the nature of the storm and how to turn it back.

-the current carries a lone boat far out to sea. The storm approaches. Do the players decide to let the fisherman (who has been very helpful, and who's daughter is very upset) drown as they defeat the storm, or do they put one man's life above all the others at risk?

-a small islet with a secret buried in a small cave. It could help them in their endeavors here, but local myth tells of a fearsome guardian (a huge shark or an octopus or a ghost or a ghost shark or whatever).

[Pizza Lord]

The Old Man was preparing out on the cliffs, when he slipped on a wet rock. He fell, broke an ankle or wrist, but the Storm Breaker fell into the waves at the bottom.

The PCs must search it out (or face the Embodiment without it, which would destroy the village during the fight). It either washed with current into some sea caves (accessed underwater, though they could connect elsewhere) or was carried into it by a giant octopus or sahaugin or something. Either just on their own or serving the Embodiment.

Possibly defeating the creature(s), they find the axe handle has been broken or splintered. Make whole can fix it, but the Old Man says the (important) enchantment is lost. It needs a new handle from a sunken ship wrecked on the rocks nearby 'The Stormbringer.' Possibly from the old mast which is just visible below the surface of the water. Or from something else deeper in the ship itself if you want some exploration.

[DungeonmasterCal]

Ooooooh...that's good.