The adjective intensifying describes something that is increasing in strength or degree. The intensifying snowstorm may cause your neighbors to rush to the store for bread and milk, but if you grew up with lots of snow, you know there is no need to panic.
Intensifying is from the verb intensify, a word coined by the famous poet Samuel Taylor Coleridge. He first used the word in a book to describe the effects of opium — a pain killer which was still legal to buy. He promptly apologized for the new word in a footnote that read in part, "I have therefore hazarded the word, intensify: though, I confess, it sounds uncouth to my own ear." Even so, poetry can be an intensifying use of ordinary language.