Your choices are: Adverb, Verb, Noun, and Adjective. A sentence cannot be either one of these as those are types of words.
The Weatherman, Storms, and Afternoon are nouns as they are people, places, or things.
Warned and expect are verbs as they are actions.
There are no adverbs as no verb is given any details or description.
There are no adjectives as none of the nouns are described. Hope this helps!