Fix limits on skew-T example.
Fix limits on skew-T example.

ahill818/MetPy,deeplycloudy/MetPy,Unidata/MetPy,jrleeman/MetPy,dopplershift/MetPy,jrleeman/MetPy,ahaberlie/MetPy,dopplershift/MetPy,ahaberlie/MetPy,ShawnMurd/MetPy,Unidata/MetPy