Something exceptional, substantial, or great is prodigious. A blizzard includes prodigious wind and snow. A prodigious writer is one who can write a lot and do it well.
Prodigious is a word for things that are impressive. If you have prodigious strength, you're very strong. If your cat had a prodigious litter of kittens, then you've got a houseful of kittens. This is a strong word that's also kind of formal. Save it for things that really blow you away because of their quality or quantity. A little drizzle isn't a prodigious rain, but a storm that floods a whole city certainly is.