WTIMINC is a parameter in the fort.15 file that informs the model of the meteorological forcing time interval in seconds.
WTIMINC is required unless you are using the parametric vortex model for meteorology (refer
NWS). WTIMINC is usually a single integer. An exception this is when
NWS = -14, where the first value indicates the time interval of the GRIB2/NetCDF dataset, and the second value indicates the time interval of the OWI dataset.