The Prodigal Mage — Karen Miller

Many years have passed since the last Mage War. It has been a time of great change. But not all changes are for the best, and Asher's world is in peril once more.
The weather magic that keeps Lur safe is failing. Among the sorcerers, only Asher has the skill to mend the antique weather map that governs the seasons, keeping the land from being crushed by natural forces. Yet, when Asher risks his life to meddle with these dangerous magics, the crisis is merely delayed, not averted.

Asher's son Rafel inherited his father's talents, but he has been forbidden to use them. With Lur facing devastation, however, he may be its only hope.