system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Recently my hometown got 9" of snow, and the forecast was 8-12 inches. How can this (and other weather) be predicted so accurately so far in advance?
gpt
Centuries of record keeping helps us see patterns and trends, decades of tracking weather patterns and results and feeding into ever-improving computer modeling, better data collection using radar and satallites, and every day we understand better the sciences behind weather which allows us to improve our computer modeling and amount of data we can track and document.  

And for all that we still get it wrong.  A lot.