aber liegt denn schon irgendwo Schnee

This phrase is from Lesson 7.1, and translates as "but is there snow anywhere?".

The discussion doesn't really mention "denn schon" which I think means something like "then already".

Is it one of those "filler" expressions that can take various meanings in translation?

I think this is about modal particles - English does not have them so they cannot be directly translated. The are used to express the speakers mood or attitude to what is being said.
The confusing thing is that modal particles have normal meanings such as denn -  because

Denn is a very common one that appears a lot later  in the course, but I am surprised to see it in level 1. It is often used in questions to express interest. 

You can often recognise modal particles because they can be omitted without changing the fundamental meaning of the sentence and they don't seem to fit.

According to my grammar book, schon can also be a modal particle, but the meaning of schon - "already" works in the sentence so it probably isn't one.

I think you could translate the sentence semi literally as
"But is there already snow lying anywhere."

Tutors, did I get this right?
 

Hi Peter--252 and sfpugh,

sfpugh, you are absolutely right and your explanation is very thorough. In the sentence above, the modal particle "denn" is being used to emphasise or intensify "schon" which means already. But it is also added to show the speakers interest as you said. 

Over time you will become more familiar with recognising modal particles and eventually start using them yourself which will make you sound much more like a native speaker.

Viele Grüße
Julia

Thanks for the explanation!

I also note that sfpugh brought this subject up a couple of years ago:

https://members.rocketlanguages.com/members/forum/german-feedback-and-comments/modal-particles-should-the-course-include-a-brief-explanation-as-they-appear-quite-often 

and I agree this could be useful, once one has gone beyond the basics.

And for Julia's suggestion, I'll keep my eyes and ears open to try to familiarise myself with the kind of expressions!

Vielen Dank & Viele Grüße
Peter