Here is a table showing what variables are available at each level:
<pre>

Table of Levels and Variables (max 37 grids per analysis time)

      100  z t u v
      200  z t u v
      250  z t u v            (starts 75nov30, ends 86nov29)
      300  z t u v
      500  z t u v mr
      700  z t u v mr
      850  z t u v mr
     1000  z t u v mr
      msl  slp
</pre>
<br>
ds108.0_variables.