Really recommend reading http://jackadam.github.io/2011/how-dark-sky-works/ http://jackadam.github.io/2011/how-dark-sky-works/ and https://en.wikipedia.org/wiki

Really recommend reading http://jackadam.github.io/2011/how-dark-sky-works/ http://jackadam.github.io/2011/how-dark-sky-works/ and https://en.wikipedia.org/wiki/Weather_radar#How_a_weather_radar_works https://en.wikipedia.org/wiki/Weather_radar#How_a_weather_ra... to get something of a handle on it For one thing, the resolution of radar is finite where one "pixel" (gate) is quite large, and everything under it is assumed to be constant. Precipitation at a spot on the ground is the result of everything happening from sea level up 40,000', and we don't have exact properties (temperature, dew point, humidity) for the atmosphere at all of those locations. We can fill in some gaps with models on supercomputers, but they're just models.