Liquid precipitation and snow precipitation measurements having a first resolution and spanning a first time period are aggregated with data from a computer generated model of current liquid precipitation and snowfall estimates having a second resolution and spanning a second time period to form near up-to-date estimates of liquid precipitation and snowfall over a determined time period. The measurements are received from various weather history data severs over a network. The data is processed into a gridded data set for a determined geographical region. The current conditions estimates are received over a network from a different sever. The processor then aggregates the processed liquid and snow precipitation estimates with the current precipitation estimates corresponding to the period from the most recent precipitation and snowfall data until present.