You are right considering Mark Margavage's degree curriculum only includes up to calculus 1 and just synoptic meteorology, a far cry from the standard education requirements one must achieve to call themselves a meteorologist:
https://catalog.wilkes.edu//preview_program.php?catoid=13&poid=1760
https://wilkes.meritpages.com/stories/Wilkes-University-Awards-Degree-to-Mark-Margavage-of-Edwardsville-Pa-18704-/7693061
a standard meteorology path should include up to partial differential equations and a whole slew of thermodynamics and dynamics classes. 99% sure he never took any of those classes.