Hi guys, I wonder if anyone can help.

I'm trying to create a fantasy world to set fiction and an RPG in, and Fractal Terrains 3 is giving awesome results. However, there's one problem- no matter what I do, I can't seem to generate worlds that have any deserts; the only regions with less than 10in of rainfall a year are the icy ones. The world just doesn't seem complete without some sandy deserts.

Here are the settings I'm using:

Synthetic World
Highest Peak 30000ft
Lowest Depth -30000ft
Circumference 25000 miles
World Seed 938497408
Wilbur Ridged Multifractal
Rouhgness 0.70
Percent Sea 57
Land size 2.58

Any help would be greatly appreciated.