SEARCH

     SEARCH controls the search radius in an objective analysis program.  
     The radius is the maximum distance that a station may be from a grid 
     point to be used in the analysis for that point.  The search radius 
     is set so that stations whose weighting factor is less than 
     EXP (-SEARCH) are not used.  SEARCH must have a value in the range 
     1 - 50.  If the value is outside this range, a default value of 20 
     is used.  If SEARCH is given a very small value, many grid points 
     will not have three stations within the search area, and consequently 
     will be set to the missing data value.

     SEARCH may also be used to set a flag to allow extrapolation of data 
     values to grid points on the periphery of the data area.  To do this, 
     follow the value of SEARCH with /EX; for example, SEARCH = 20/EX will 
     result in data extrapolation.