The grad classes can be easier or harder, depending on what kind of study habits and mental retention you have. Most of it is old stuff rehashed and more deeply investigated. The classes you take can also make a big difference, which are tailored to which part of meteorology you want to concentrate in.
What kind of GPA got you into your grad. program, if you don't mind me asking? I only ask because I had a 3.31 GPA (and something like 28 or 29 GRE), and I struggled getting into grad school. Of course, part of it was the fact that last year was one of the hardest years to try to get into grad school. When I applied in fall 2009, most colleges had cut back on the number of paid graduates. For instance, SUNY Albany cut their incoming RA/TA positions in half, and I was 2nd in line on the waiting list, so I got screwed over there Any other year before that and I would have gotten in.