CUTDOWN         41   N   cut down flag
DD               1   N   wind direction
FF               2   N   wind speed
HT              16   N   geometric height   
LAT             17   N   latitude
LON             18   N   longitude                            
P               35   N   pressure calulated                    
POBS            42   N   pressure observed
RH              20   N   relative humidity                    
T                5   N   air temperature                      
U                3   N   u wind component
V                4   N   v wind component
