National Oceanic and Atmospheric Administration (NOAA) has a FREE middle school unit on the essential principles of climate science titled: Discover Your Changing World. Click HERE to download the entire PDF or individual activities. These materials could be useful in helping to meet some of the weather/climate related expectations in the NGSS. The resource was recently revised but does not contain direct correlations to the NGSS or the Framework for K-12 Science Education but I’m assuming that NOAA is working on this…? Also, see Chris Ohana’s brief critique of the materials in the comment section.
If you are a middle school science teacher or a science curriculum specialist- please leave your thoughts in the comments- Does this look like a useful supplemental resource? Why/why not? How might you use this?
Science for All 
I looked through it and it seemed like a disconnected set of activities without a real unifying big idea or clear learning progression. The GEMS Ocean curriculum for 3-6 and their new middle school climate change module are much better. Of course, they aren’t free, though.
Thanks Chris- this is very helpful feedback