Weather Generation: BWh Climate

The players in my campaign are heading north from Thyatis up to Ylaruam and I'm in need of a new weather generator for the desert climate.  I increased the chance of thunderstorms during rain. For the moment, until I do more in depth analysis, I'm applying a dominant wind from the North with a -3 applied to wind speeds; this is due to a high pressure zone over Ethengar which would expand in the summer months over the altan tepes in rockhome(based on my wind pattern map). For those regions near the mountains, the wind would be coming off them, either from the west, or the south, depending on location. Basically Ylaruam is surrounded by high pressure zones over the altan tepe mountains and the wind comes from all directions to meet in the lowlands, driving away any moisture from the sea to the east. So as much as many in the fan community might think ylaruam shouldn't be a desert, the presence of high pressure from the mountains and its latitude actually makes the presence of a desert reasonable. Though this is based on my own educated guesswork, I have yet to make an accurate simulation of winds and currents that would really show this definitively.