Cloud cover is accounted for using a simple stochastic cloud simulator. Probability of cloudiness is based upon elevation, season, and time of day. This number represents the average flux during a particular hour. This method uses a modified sine function for daytime temperatures and an exponential decay function for nighttime temperature. The elevations of these stations range from near sea level to 1059 meters.
Relative humidity is modeled as a function of temperature and water vapor content.
Rainfall is modeled using a rainfall-elevation regression equation from Garcia, et al. This monthly pattern is used to derive monthly values of rainfall at all points in the forest. Thus, any differences in the pattern of monthly rainfall, due to elevation or location, are not accounted for in this version. Daily or hourly rainfall estimates are not available using this model. The primary DEM covers the entire Caribbean National and Luquillo Experimental Forest with a 30 meter by 30 meter grid.