NIMROD product data are in the non-standard NIMROD binary format. Refer to linked documentation for further details. However, the documentation does not indicate there are three 4 byte elements in each record. These are located before each block of data within the record, the first and second should be equal to 512 to confirm the size of the next data block; the third should be equal to twice the size of the data grid (e.g. if the data are in a grid 200 by 500 boxes, then this third entry should be 200,000).The data files contain integer precipitation rates in unit of (mm/hr)*32. Each value is between 0 and 32767. In practice it is rare to see a value in excess of 4096 i.e. 128 mm/hr.