Since I in some way initiated this discussion, I feel like explaining why I did it and giving my 2 cents about this particular tag in GIS SE.
I have to say that I am almost completely GIS-ignorant. I do know a bit about it, I even set up PostGIS and Open Street Map ready databases myself, but I never used, analyzed or manipulated that data. I am a Python programmer and my purpose in the company is related to RESTful API development.
Just recently we started to gather world-wide weather-related data and for the first time in my life I came across GRIB files. It took me a while to figure out what those files represent and how to use them. After few days of "research", I still feel like I know almost nothing about those, just because I feel like each and every web site dedicated to this topic is just terrible. I don't even understand how people can browse those pages and find actual information, especially if you are into professional meteorological terms for the first time in your life. Starting from the visual representation (10 different CSS styles on same domain???), tons of broken links, etc, etc...
In my mind, GRIB files are just bunch of data related to planet Earth and different weather conditions across the globe. GIS data however is (in my mind) exactly the same, except from the weather part but with some other specific additions. That is my basic, simple (and ignorant) way of looking at those two things. Since both are based strictly on Earth-related data, in my simplistic mind they are very much related. I agree that I might be completely wrong about it, but, after few days of being unable to clarify in my head the most simple things about GRIB files, I decided to look for an answer in GIS SE community. Main reason for this was being unable to find it in "official documentation" (if you can call it that way), various forums, IRC, googling for it or anywhere else. This community was seriously my final chance to get some proper information about it.
Before I asked my first question, I did look for "GRIB" and "Python" tags here. Seeing that there was some active discussion about both, I felt like this is a good place to ask. I extremely appreciate amount of helping in each and every SE community and I was incredibly happy to see that people are discussing about GRIB files here but I was very surprised to see the amount of rejecting any help regarding it.
Back to the topic...
- Is it spatial data? I would say yes.
- Is it GIS-related data? I would say yes (at least looking at the acronym here - Geographic Information System - GRIB files contain nothing but "geographic information weather data").
- Is it off-topic? No. As alpha-beta-soup pointed out, you have to look at the bigger picture here. I can find lots of questions in this community which could be marked off-topic, but still are answered and never marked as a problematic by anyone.
GRIB files are also widely used by GIS community. Although I know almost nothing about those two combined together, extremely simple Google search told me that there are plenty of GIS-related websites explaining how to use GRIB data in GIS software:
For the sake of helping developers (and other people) with GRIB data, and especially because "official documentation" is almost unreadable, I vote for keeping this tag on-topic because I seriously feel that this might be the only place to get a proper answers about it.