Many fields have seconds in their units e.g. precipitation and radiation fields. How can instantaneous values be calculated?

Some forecast fields (fluxes) are accumulated from the start of the forecast, so to get averaged values you need to divide by the length of the forecast (the forecast step). In this way the average between the start of the forecast and the forecast step is obtained.   To obtain the average between two forecast steps (e.g. STEP1 and STEP2) it is necessary to retrieve the fields for the two steps:

( FLD ( STEP1) and FLD( STEP2))

then calculate the difference and divide by the time difference in seconds:

( FLD( STEP2)- FLD( STEP1))/(( STEP2-STEP1)*3600).