So I had this idea, i'm no story teller...so i'll just explain quickly xD

But I feel like when Vitani first hears simba talk about "The great kings" living amongst the stars...Vitani feels no solace with her mother or brothers death...So she wonders where they may be...

Its sort of sad to think, but maybe her family is in the rain. Since they never got out their anger in life they still brew up in the heavens and come out during great storms. Violent winds, chilling rain, great thunder. Never can they find peace.