This dataset contains parameter values for the Precipitation Isosceles Triangle (PITRI) precipitation disaggregation method (Bohn et al., 2019) over the CONUS+Mexico domain (southern Canada, the continental US, and Mexico; 14.65 - 53° N latitude, 65-125° W longitude), at 1/16° (6 km) spatial resolution. There are two parameters: "dur" (mean event duration [minutes]) and "t_pk" (mean time of peak precipitation intensity [minutes from beginning of day]).  In each land grid cell, each parameter has 12 climatological mean monthly values for the period 1981-2013. This dataset contains 2 NetCDF-format files: domain.CONUS_MX.L2015.nc  - this contains parameters over the entire CONUS+Mexico domain, using the land mask of the Livneh et al. (2015) daily meteorology dataset. domain.USMX.L2015.nc - this contains the same parameters, but clipped to exclude Canada (to be consistent with datasets that cover only that part of the domain). These files are structured as input "domain" files for 2 applications: MetSim meteorology simulator (https://github.com/UW-Hydro/MetSim/releases/tag/2.0.0_alpha; Bennett et al., 2018). The PITRI algorithm has been implemented as an option in MetSim. To use this algorithm within MetSim, set the "prec_type" option to "triangle" or "mix" in the configuration file. The "mix" option is a blend of the "uniform" (previous) method and the "triangle" method that fixes biases in snow accumulation rates yielded by the "triangle" method in some climates. "mix" uses the "uniform" method on days for which minimum daily temperature falls below 0 C, and "triangle" method on all other days. Variable Infiltration Capacity (VIC) model, release 5.0 and later (Liang et al., 1994; Hamman et al., 2018; https://github.com/UW-Hydro/VIC). VIC does not use the PITRI parameters, but does use the other variables such as mask, elevation, area, etc. For VIC to use the output of MetSim (disaggregated meteorological fields) as input, VIC needs to use the same domain file as was used in MetSim. Algorithm details can be found in the following paper, which should be cited if you use this dataset: Bohn, T. J., K. M. Whitney, G. Mascaro, and E. R. Vivoni, 2019: A deterministic approach for approximating the diurnal cycle of precipitation for use in large-scale hydrological modeling, Journal of Hydrometeorology 20(2), 297-317, doi: 10.1175/JHM-D-18-0203.1.