I want to test some 3D weather radar software by simulating rainy weather. I want some degree of realism in the sense that it simulates rain systems and their boundaries and also simulates rain rates over their volumes. Weather systems should be dynamic in the sense that they can evolve and change at typical rates.
I would be satisfied with a statistical model if that's possible, rather than one driven by solving differential equations, based on my assumption that generating random numbers is easier than solving large systems of equations.
The model should be capable of running for long periods of time (a few hours of simulated real time) while generating an assorted set of weather patterns (clear weather and various levels of rain intensity). It should be suitable for real time simulation of the radar software, so weather development over time is an important requirement.
Being able to support real-time simulation is another reason I am leaning toward any more simplistic (by arguably reasonable) model.
I don't know where to begin finding a model like this. The models I have seen appear to be more complex than I would like, and probably not really suitable for my limited requirement.
What would help me is to identify any existing models that might be used for this purpose or any literature that describes how to create a model like this.