Questions & Answers about Hier gibt es viel Schnee.
Why does this sentence use "gibt es" to mean "there is"?
In German, the set phrase for "there is" or "there are" is es gibt (literally: it gives). It acts like an impersonal phrase, just like how we use es to say "it is raining" (es regnet). You will use es gibt anytime you want to state that something exists somewhere.
Why are the words swapped to "gibt es" instead of "es gibt"?
This happens because of the German verb-second rule. In a regular statement, the main verb must be the second piece of information. Since the sentence starts with the location Hier (Here), the verb gibt has to come next. The subject es (it) gets pushed to the third position.
Why do we use "viel" here instead of "viele"?
The word viel means "much" and is used for uncountable things, like Schnee (snow), water, or time. You would use viele (many) when talking about things you can count individually, like viele Autos (many cars).
I learned that "es gibt" always takes the accusative case. Why doesn't the word for snow change here?
You are right that the thing existing after es gibt is the direct object, which requires the accusative case. However, you usually only notice the accusative change when there is an article, like einen or den for masculine nouns like Schnee. Since this sentence just says viel Schnee without "a" or "the", the spelling does not look any different.