Make the meteogram script only use data from the last 24 hours when plotting current, in addition to setting an appropriate range.  This fixes the problem of plotting limits being determined by data that is not shown.
Make the meteogram script only use data from the last 24 hours when plotting current, in addition to setting an appropriate range.  This fixes the problem of plotting limits being determined by data that is not shown.

git-svn-id: acf0ef94bfce630b1a882387fc03ab8593ec6522@222 150532fb-1d5b-0410-a8ab-efec50f980d4

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