Originally posted by Draklar
Originally posted by Seytra
Yes, but they don\'t originate in caves, but in outer space.
Originally posted by Wikipedia
A meteor is the visible path of a meteoroid that enters the Earth\'s (or another body\'s) atmosphere
That line refers to meteoroid, not meteor 
\"A
meteor is the visible path
of a meteorid\", so it clearly refers to a meteor.
Originally posted by Draklar
Some inhabitants of Yliakum remember snow from before entering the underground (as stated in the setting),
Up until now I am unable to recognise the char creation as part of the setting, as it has absolutely no interconnections with it, and most importantly, has no foundation there. In fact, it could just as easily be an alternative setting entirely. In fact, several things in it, like the naming / descriptions of the months, seem to contradict the spirit of the settings.
The term azure
sun, OTOH, is in the original settings and therefore undeniably connected (see below).
Originally posted by Draklar
so I don\'t see why it couldn\'t be so with meteors... Actually, the spell might be something completely different than meteor, but since people would find it very similar to what they experienced on the surface, they might name them after those 
Yes, that\'s what I was trying to say with the post before my previous one. The previous post merely said that the definition of meteor as presented by spydirweb would be way too broad to, on it\'s own, give rise to a spell like that,
especially if developed inside a cave.
I agree that the term / inspiration for the spell \"meteor\" can be a remainder from the first settlers who came from a planetary surface.
Originally posted by TheMinority
well, rain and clouds could, theoretically, be plausible. with the warm, moist air rising to the top, it would condense on the cool rock above. some could condense in the air to form clouds. the water that has cooled on the rock, however, would simply fall back down. hence: rain.
If the ceiling isn\'t exactly horizontal, then the condensing water would not fall down but instead run down, at the underside of the ceiling, and thus form \"rivers\" that run along the ceiling and then down the walls, where it eventually meets ground level. This can be observed in cooking pots.
Given that the ceiling is by no means even, a different scenario would be possible, but has an important implication:
If the condensing water forms a river, it\'ll encounter the uneven surface and follow them to the nearest point that is lowest. That would be spikes hanging from the ceiling.
From the tips of these, the water would fall down, as it has no other way to go.
Result: instead of rain, which would fall anywhere within the region with the same probability, there would be distinct places where water falls down, and not in form of distributed drops but instead of a continous trickle or even flow. This is just like in normal caves, and the reason why stalactites / stalagmites form: water containing lime dripping from uneven spots, leaving some of the lime, which then forms the growing stalactite. With condensed water, no lime would be contained, thus no stalactites would form, but the water would still drip down in the exact same places all the time.
Originally posted by TheMinority
hail could also work, the moist air condensing into clouds, then freezing and falling back.
AFAK clouds form because the upper atmosphere is cooler than below, inhibiting the water from rising higher. However, I don\'t think that the upper atmosphere in the cave would be notably cooler than at ground level, given that the crystal would directly heat it. So all water would reach the cavern ceiling, condensing there as above, or be dissociated by the crystal (which is a problem, as that would mean that air is dissociated as well, eventually burning all the atmosphere of the planet, unless it\'s merely split into individual atoms that would eventually reconnect (high danger of hydrogen explosion unless ventilated very well)).
So the only thing I can see forming would be ice spikes but neither snow nor hail nor real rain.
Originally posted by TheMinority
lightning would be something more difficult to explain.
Indeed the most common way for lightning to form (water particles in clouds) doesn\'t work AFAICS. There are other, much rarer ways for lightning to form, though (dust particles). An interesting effect would be that lightning would not only strike ground, but also the ceiling and the walls.