The key that helped me understand why there are jet streams was a "pressure block" activity that I did while taking the DataStreme (online) Course offered by the American Meteorological Society. Although I don't have students do the activity, I use photos of the blocks in my presentation. The topics covered in the PowerPoint are . . .
3. Why are they important?
NOTE: The presentation is posted on www.slideboom.com - a free site that allows you to post up to 100 presentations, which students or colleagues can view or download. To view other presentations that I've posted type "rod benson" into the search box.