dset ^tpw%y4_mon.grd
undef -999.9
title NVAP Water vapor Total Precip Water 
options template yrev
*format yrev
XDEF  144 LINEAR   1.25  2.5
YDEF  72  LINEAR  -88.75 2.5
zdef     1 levels .5 
tdef 144  linear    12Z01JAN1988     1mon
vars    1
tpw      1 212,8,0 total precip water (mm)                   
endvars
* title:tpw: NVAP Total Precipitable Water $_month $_year