Extrapolating pressure levels below ground level

[cyclone6]

Has NCL graphics incorporated a way to extrapolate below ground level yet? The last question I saw on this issue was back in '09, I think... Without extrapolation, 850 mb and 700 mb are virtually useless in the west.

If it can't, any suggestions on how to generate these plots?

Thanks in advance!

[cyclone6]

Just in case somebody else has this question:

I just stumbled across it today. NCL has a command that will do this. Its the wrf_user_vert_interp function,
along with "opts@extrapolate (logical) - whether to extrapolate values below ground (default=False)"

I haven't had a chance to play with this yet, but that seems to be the answer.