§ Akallabêth The Silmarillion

Now aforetime in the isle of Númenor the weather was ever apt to the needs and liking of Men: rain in due season and ever in measure; and sunshine, now warmer, now cooler, and winds from the sea. And when the wind was in the west, it seemed to many that it was filled with a fragrance, fleeting but sweet, heart-stirring, as of flowers that bloom for ever in undying meads and have no names on mortal shores. But all this was now changed; for the sky itself was darkened, and there were storms of rain and hail in those days, and violent winds; and ever and anon a great ship of the Númenóreans would founder and return not to haven, though such a grief had not till then befallen them since the rising of the Star. And out of the west there would come at times a great cloud in the evening, shaped as it were an eagle, with pinions spread to the north and the south; and slowly it would loom up, blotting out the sunset, and then uttermost night would fall upon Númenor. And some of the eagles bore lightning beneath their wings, and thunder echoed between sea and cloud.