[Legolas]

The storm was the "ill will of Caradhras."

Gimli speaks more of it (in addition to the quote above):

Gimli looked up and shook his head. `Caradhras has not forgiven us.' he said. `He has more snow yet to fling at us, if we go on. The sooner we go back and down the better.'

`Ah, it is as I said,' growled Gimli. 'It was no ordinary storm. It is the ill will of Caradhras. He does not love Elves and Dwarves, and that drift was laid to cut off our escape.'
'But happily your Caradhras has forgotten that you have Men with you,' said Boromir, who came up at that moment. `And doughty Men too, if I may say it; though lesser men with spades might have served you better. Still, we have thrust a lane through the drift; and for that all here may be grateful who cannot run as light as Elves.'

`Yonder is the Dimrill Stair,' said Aragorn, pointing to the falls. 'Down the deep-cloven way that climbs beside the torrent we should have come, if fortune had been kinder.'
`Or Caradhras less cruel,' said Gimli. `There he stands smiling in the sun! ' He shook his fist at the furthest of the snow-capped peaks and turned away.